Mechanical engineering is the study of physical
machines
A machine is a physical system using power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecul ...
that may involve
force
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a p ...
and movement. It is an
engineering branch
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
that combines
engineering physics
Engineering physics, or engineering science, refers to the study of the combined disciplines of physics, mathematics, chemistry, biology, and engineering, particularly computer, nuclear, electrical, electronic, aerospace, materials or mechanical en ...
and
mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
principles with
materials science, to
design
A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process or the result of that plan or specification in the form of a prototype, product, or process. The verb ''to design' ...
, analyze, manufacture, and maintain
mechanical systems. It is one of the oldest and broadest of the
engineering branches.
Mechanical engineering requires an understanding of core areas including
mechanics
Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objects r ...
,
dynamics,
thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of th ...
,
materials science,
structural analysis, and
electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describ ...
. In addition to these core principles, mechanical engineers use tools such as
computer-aided design (CAD),
computer-aided manufacturing
Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...
(CAM), and
product lifecycle
In industry, Product Lifecycle Management (PLM) is the process of managing the entire lifecycle of a product from its inception through the engineering, design and manufacture, as well as the service and disposal of manufactured products. PL ...
management to design and analyze
manufacturing plants
A factory, manufacturing plant or a production plant is an industrial facility, often a complex consisting of several buildings filled with machinery, where workers manufacture items or operate machines which process each item into another. T ...
,
industrial equipment
Industrial technology is the use of engineering and manufacturing technology to make production faster, simpler, and more efficient. The industrial technology field employs creative and technically proficient individuals who can help a company ac ...
and
machinery,
heating and cooling systems,
transport
Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...
systems,
aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engine ...
,
watercraft
Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail, ...
,
robotics
Robotics is an interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist humans. Robotics integrat ...
,
medical devices
A medical device is any device intended to be used for medical purposes. Significant potential for hazards are inherent when using a device for medical purposes and thus medical devices must be proved safe and effective with reasonable assura ...
,
weapons
A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...
, and others.
Mechanical engineering emerged as a field during the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
in Europe in the 18th century; however, its development can be traced back several thousand years around the world. In the 19th century, developments in
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
led to the development of mechanical engineering science. The field has continually evolved to incorporate advancements; today mechanical engineers are pursuing developments in such areas as
composites,
mechatronics
Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics, ...
, and
nanotechnology. It also overlaps with
aerospace engineering,
metallurgical engineering
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the sc ...
,
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage ...
,
structural engineering
Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and muscles' that create the form and shape of man-made structures. Structural engineers also must understand and cal ...
,
electrical engineering,
manufacturing engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
,
chemical engineering
Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials int ...
,
industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information a ...
, and other engineering disciplines to varying amounts. Mechanical engineers may also work in the field of
biomedical engineering
Biomedical engineering (BME) or medical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes (e.g., diagnostic or therapeutic). BME is also traditionally logical sciences ...
, specifically with
biomechanics
Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to organs, cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of ...
,
transport phenomena
In engineering, physics, and chemistry, the study of transport phenomena concerns the exchange of mass, energy, charge, momentum and angular momentum between observed and studied systems. While it draws from fields as diverse as continuum mecha ...
,
biomechatronics
Biomechatronics is an applied interdisciplinary science that aims to integrate biology and mechatronics (electrical, electronics, and mechanical engineering). It also encompasses the fields of robotics and neuroscience. Biomechatronic devices encom ...
,
bionanotechnology
Nanobiotechnology, bionanotechnology, and nanobiology are terms that refer to the intersection of nanotechnology and biology. Given that the subject is one that has only emerged very recently, bionanotechnology and nanobiotechnology serve as blan ...
, and modelling of biological systems.
History
The application of mechanical engineering can be seen in the archives of various ancient and medieval societies. The six classic
simple machines were known in the
ancient Near East
The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia (modern Iraq, southeast Turkey, southwest Iran and northeastern Syria), ancient Egypt, ancient Iran ( Elam, ...
. The
wedge
A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converti ...
and the
inclined plane
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six clas ...
(ramp) were known since
prehistoric times. The
wheel, along with the
wheel and axle
The wheel and axle is a simple machine consisting of a wheel attached to a smaller axle so that these two parts rotate together in which a force is transferred from one to the other. The wheel and axle can be viewed as a version of the lever, wi ...
mechanism, was invented in
Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
(modern Iraq) during the 5th millennium BC. The
lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is d ...
mechanism first appeared around 5,000 years ago in the Near East, where it was used in a simple
balance scale
A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, and weight balances.
The traditional scale consists of two plates or bowls suspended at equal distances from a ...
,
and to move large objects in
ancient Egyptian technology
Ancient Egyptian technology describes devices and technologies invented or used in Ancient Egypt. The Egyptians invented and used many simple machines, such as the ramp and the lever, to aid construction processes. They used rope trusses to stiff ...
. The lever was also used in the
shadoof
A shadoof or shaduf (from the Arabic word , ''šādūf'') is an irrigation tool. It is highly efficient, and has been known since 3000 BCE.
Names
It is also called a lift, well pole, well sweep, or simply a sweep in the US.Knight, Edward Henry ...
water-lifting device, the first
crane machine, which appeared in Mesopotamia circa 3000 BC.
The earliest evidence of
pulleys date back to Mesopotamia in the early 2nd millennium BC.
The
Sakia
A sāqiyah or saqiya ( ar, ساقية), also spelled sakia or saqia) is a mechanical water lifting device. It is also called a Persian wheel, tablia, rehat, and in Latin tympanum. It is similar in function to a scoop wheel, which uses buckets, ...
was developed in the
Kingdom of Kush
The Kingdom of Kush (; Egyptian: 𓎡𓄿𓈙𓈉 ''kꜣš'', Assyrian: ''Kûsi'', in LXX grc, Κυς and Κυσι ; cop, ''Ecōš''; he, כּוּשׁ ''Kūš'') was an ancient kingdom in Nubia, centered along the Nile Valley in wh ...
during the 4th century BC. It relied on animal power reducing the tow on the requirement of human energy.
Reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
s in the form of
Hafirs
A hafir is an artificially constructed water catchment basin with a circular earthen wall and diameters of between 70-250 m and heights of up to 7 m. Adapted to semi-desert conditions, the hafirs catch the water during the rainy season to ...
were developed in Kush to store water and boost irrigation.
[Fritz Hintze, Kush XI; pp.222-224.] Bloomeries and
blast furnaces were developed during the seventh century BC in
Meroe.
Kushite
sundials
A sundial is a horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat ...
applied mathematics in the form of advanced trigonometry.
The earliest practical
water-power
Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a wa ...
ed machines, the
water wheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or bucket ...
and
watermill
A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of ...
, first appeared in the
Persian Empire, in what are now Iraq and Iran, by the early 4th century BC. In
ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
, the works of
Archimedes (287–212 BC) influenced mechanics in the Western tradition. In
Roman Egypt,
Heron of Alexandria
Hero of Alexandria (; grc-gre, Ἥρων ὁ Ἀλεξανδρεύς, ''Heron ho Alexandreus'', also known as Heron of Alexandria ; 60 AD) was a Greek mathematician and engineer who was active in his native city of Alexandria, Roman Egypt. He i ...
(c. 10–70 AD) created the first
steam-powered
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be tr ...
device (
Aeolipile
An aeolipile, aeolipyle, or eolipile, from the Greek "αιολουπυλη", also known as a Hero's engine, is a simple, bladeless radial steam turbine which spins when the central water container is heated. Torque is produced by steam jets exi ...
). In
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
,
Zhang Heng (78–139 AD) improved a
water clock
A water clock or clepsydra (; ; ) is a timepiece by which time is measured by the regulated flow of liquid into (inflow type) or out from (outflow type) a vessel, and where the amount is then measured.
Water clocks are one of the oldest time- ...
and invented a
seismometer
A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The outpu ...
, and
Ma Jun (200–265 AD) invented a chariot with
differential gears. The medieval Chinese horologist and engineer
Su Song (1020–1101 AD) incorporated an
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
mechanism into his
astronomical
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxi ...
clock tower two centuries before escapement devices were found in medieval European clocks. He also invented the world's first known endless power-transmitting
chain drive.
During the
Islamic Golden Age
The Islamic Golden Age was a period of cultural, economic, and scientific flourishing in the history of Islam, traditionally dated from the 8th century to the 14th century. This period is traditionally understood to have begun during the reign ...
(7th to 15th century),
Muslim inventors made remarkable contributions in the field of mechanical technology.
Al-Jazari, who was one of them, wrote his famous ''
Book of Ingenious Devices
The ''Book of Ingenious Devices'' (Arabic: كتاب الحيل ''Kitab al-Hiyal'', Persian: كتاب ترفندها ''Ketab tarfandha'', literally: "The Book of Tricks") is a large illustrated work on mechanical devices, including automata, pub ...
'' in 1206 and presented many mechanical designs.
In the 17th century, important breakthroughs in the foundations of mechanical engineering occurred in
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
and the
Continent
A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven ...
. The Dutch mathematician and physicist
Christiaan Huygens invented the
pendulum clock
A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator: It swings back and forth in a precise time interval dependent on i ...
in 1657, which was the first reliable timekeeper for almost 300 years, and
published a work dedicated to clock designs and the theory behind them. In England,
Isaac Newton
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a " natural philosopher"), widely recognised as one of the grea ...
formulated
Newton's Laws of Motion
Newton's laws of motion are three basic laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows:
# A body remains at rest, or in moti ...
and developed the
calculus
Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...
, which would become the mathematical basis of physics. Newton was reluctant to publish his works for years, but he was finally persuaded to do so by his colleagues, such as
Edmond Halley
Edmond (or Edmund) Halley (; – ) was an English astronomer, mathematician and physicist. He was the second Astronomer Royal in Britain, succeeding John Flamsteed in 1720.
From an observatory he constructed on Saint Helena in 1676–77, H ...
.
Gottfried Wilhelm Leibniz
Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of math ...
, who earlier designed a
mechanical calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators we ...
, is also credited with developing the calculus during the same time period.
During the early 19th century Industrial Revolution,
machine tool
A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All ...
s were developed in England,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
, and
Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
. This allowed mechanical engineering to develop as a separate field within engineering. They brought with them manufacturing machines and the engines to power them. The first British professional society of mechanical engineers was formed in 1847
Institution of Mechanical Engineers
The Institution of Mechanical Engineers (IMechE) is an independent professional association and learned society headquartered in London, United Kingdom, that represents mechanical engineers and the engineering profession. With over 120,000 member ...
, thirty years after the civil engineers formed the first such professional society
Institution of Civil Engineers
The Institution of Civil Engineers (ICE) is an independent professional association for civil engineers and a charitable body in the United Kingdom. Based in London, ICE has over 92,000 members, of whom three-quarters are located in the UK, whi ...
. On the
European continent
Continental Europe or mainland Europe is the contiguous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by ...
, Johann von Zimmermann (1820–1901) founded the first factory for grinding machines in
Chemnitz, Germany in 1848.
In the United States, the
American Society of Mechanical Engineers (ASME) was formed in 1880, becoming the third such professional engineering society, after the
American Society of Civil Engineers
American(s) may refer to:
* American, something of, from, or related to the United States of America, commonly known as the "United States" or "America"
** Americans, citizens and nationals of the United States of America
** American ancestry, pe ...
(1852) and the
American Institute of Mining Engineers
The American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) is a professional association for mining and metallurgy, with over 145,000 members. It was founded in 1871 by 22 mining engineers in Wilkes-Barre, Pennsylvania, Uni ...
(1871). The first schools in the United States to offer an engineering education were the
United States Military Academy
The United States Military Academy (USMA), also known metonymically as West Point or simply as Army, is a United States service academy in West Point, New York. It was originally established as a fort, since it sits on strategic high groun ...
in 1817, an institution now known as
Norwich University
Norwich University – The Military College of Vermont is a private senior military college in Northfield, Vermont. It is the oldest private and senior military college in the United States and offers bachelor's and master's degrees on-campus ...
in 1819, and
Rensselaer Polytechnic Institute in 1825. Education in mechanical engineering has historically been based on a strong foundation in mathematics and science.
Education
![Archimedes-screw one-screw-threads with-ball 3D-view animated small](https://upload.wikimedia.org/wikipedia/commons/2/22/Archimedes-screw_one-screw-threads_with-ball_3D-view_animated_small.gif)
Degrees in mechanical engineering are offered at various universities worldwide. Mechanical engineering programs typically take four to five years of study depending on the place and university and result in a
Bachelor of Engineering
A Bachelor of Engineering (BEng) or a Bachelor of Science in Engineering (BSE) is an academic undergraduate degree awarded to a student after three to five years of studying engineering at an accredited college or university.
In the UK, a Ba ...
(B.Eng. or B.E.),
Bachelor of Science
A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years.
The first university to admit a student to the degree of Bachelor of Science was the University of ...
(B.Sc. or B.S.), Bachelor of Science Engineering (B.Sc.Eng.),
Bachelor of Technology (B.Tech.), Bachelor of Mechanical Engineering (B.M.E.), or
Bachelor of Applied Science
The Bachelor of Applied Science, often abbreviated as B.AS., BAS, BSAS, BASc, B.A.Sc., or BAppSc, is an undergraduate degree. There are also ''Bachelor of Arts and Science'' and ''Bachelor of Administration Science'' undergraduate degrees, also a ...
(B.A.Sc.) degree, in or with emphasis in mechanical engineering. In Spain, Portugal and most of South America, where neither B.S. nor B.Tech. programs have been adopted, the formal name for the degree is "Mechanical Engineer", and the course work is based on five or six years of training. In Italy the course work is based on five years of education, and training, but in order to qualify as an Engineer one has to pass a state exam at the end of the course. In Greece, the coursework is based on a five-year curriculum.
In the United States, most
undergraduate
Undergraduate education is education conducted after secondary education and before postgraduate education. It typically includes all postsecondary programs up to the level of a bachelor's degree. For example, in the United States, an entry-le ...
mechanical engineering programs are
accredited
Accreditation is the independent, third-party evaluation of a conformity assessment body (such as certification body, inspection body or laboratory) against recognised standards, conveying formal demonstration of its impartiality and competence to ...
by the
Accreditation Board for Engineering and Technology (ABET) to ensure similar course requirements and standards among universities. The ABET web site lists 302 accredited mechanical engineering programs as of 11 March 2014. Mechanical engineering programs in Canada are accredited by the Canadian Engineering Accreditation Board (CEAB), and most other countries offering engineering degrees have similar accreditation societies.
In
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, mechanical engineering degrees are awarded as Bachelor of Engineering (Mechanical) or similar nomenclature, although there are an increasing number of specialisations. The degree takes four years of full-time study to achieve. To ensure quality in engineering degrees,
Engineers Australia
Engineers Australia (EA) is an Australian professional body and not-for-profit organisation whose purpose is to advance the science and practice of engineering for the benefit of the community. Engineers Australia is Australia's recognized org ...
accredits engineering degrees awarded by Australian universities in accordance with the global
Washington Accord. Before the degree can be awarded, the student must complete at least 3 months of on the job work experience in an engineering firm. Similar systems are also present in South Africa and are overseen by the Engineering Council of South Africa (ECSA).
In India, to become an engineer, one needs to have an engineering degree like a B.Tech or B.E, have a diploma in engineering, or by completing a course in an engineering trade like fitter from the
Industrial Training Institute (ITIs) to receive a "ITI Trade Certificate" and also pass the All India Trade Test (AITT) with an engineering trade conducted by the National Council of Vocational Training (NCVT) by which one is awarded a "National Trade Certificate". A similar system is used in Nepal.
Some mechanical engineers go on to pursue a postgraduate degree such as a
Master of Engineering
A Master of Engineering (abbreviated MEng, M.E. or M.Eng.) is either an academic or professional master's degree in the field of engineering.
International variations
Australia
In Australia, the Master of Engineering degree is a research de ...
,
Master of Technology
A Master of Engineering (abbreviated MEng, M.E. or M.Eng.) is either an academic or professional master's degree in the field of engineering.
International variations
Australia
In Australia, the Master of Engineering degree is a research de ...
,
Master of Science
A Master of Science ( la, Magisterii Scientiae; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree in the field of science awarded by universities in many countries or a person holding such a degree. In contrast t ...
,
Master of Engineering Management
Master of Engineering Management (MEM) (or Master of Science in Engineering Management (MSEM)) is a professional master's degree that bridges the gap between the field of engineering or technology and the field of business management. Engineering ...
(M.Eng.Mgt. or M.E.M.), a
Doctor of Philosophy
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common Academic degree, degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields ...
in engineering (Eng.D. or Ph.D.) or an
engineer's degree. The master's and engineer's degrees may or may not include
research
Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness ...
. The Doctor of Philosophy includes a significant research component and is often viewed as the entry point to
academia
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, ...
. The Engineer's degree exists at a few institutions at an intermediate level between the master's degree and the doctorate.
Coursework
Standards set by each country's accreditation society are intended to provide uniformity in fundamental subject material, promote competence among graduating engineers, and to maintain confidence in the engineering profession as a whole. Engineering programs in the U.S., for example, are required by ABET to show that their students can "work professionally in both thermal and mechanical systems areas." The specific courses required to graduate, however, may differ from program to program. Universities and
institutes of technology
An institute of technology (also referred to as: technological university, technical university, university of technology, technological educational institute, technical college, polytechnic university or just polytechnic) is an institution of te ...
will often combine multiple subjects into a single class or split a subject into multiple classes, depending on the faculty available and the university's major area(s) of research.
The fundamental subjects required for mechanical engineering usually include:
*
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
(in particular,
calculus
Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...
,
differential equations, and
linear algebra
Linear algebra is the branch of mathematics concerning linear equations such as:
:a_1x_1+\cdots +a_nx_n=b,
linear maps such as:
:(x_1, \ldots, x_n) \mapsto a_1x_1+\cdots +a_nx_n,
and their representations in vector spaces and through matrices ...
)
* Basic physical sciences (including
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
and
chemistry)
*
Statics and
dynamics
*
Strength of materials
The field of strength of materials, also called mechanics of materials, typically refers to various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. The methods employed to predict the re ...
and
solid mechanics
Solid mechanics, also known as mechanics of solids, is the branch of continuum mechanics that studies the behavior of solid materials, especially their motion and deformation under the action of forces, temperature changes, phase changes, and ...
*
Materials engineering,
composites
*
Thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of th ...
,
heat transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
,
energy conversion
Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work or moving, (e.g. Lifting an object) or provides heat ...
, and
HVAC
*
Fuels
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
,
combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combusti ...
,
internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal c ...
*
Fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them.
It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and ...
(including
fluid statics
Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body " fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an imm ...
and
fluid dynamics)
*
Mechanism
Mechanism may refer to:
* Mechanism (engineering), rigid bodies connected by joints in order to accomplish a desired force and/or motion transmission
*Mechanism (biology), explaining how a feature is created
*Mechanism (philosophy), a theory that ...
and
Machine design (including
kinematics and
dynamics)
*
Instrumentation
Instrumentation a collective term for measuring instruments that are used for indicating, measuring and recording physical quantities. The term has its origins in the art and science of scientific instrument-making.
Instrumentation can refer to ...
and
measurement
*
Manufacturing engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
, technology, or processes
*
Vibration
Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic, such as the motion of a pendulum—or random, su ...
,
control theory
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a ...
and
control engineering
Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls o ...
*
Hydraulics
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...
and
Pneumatics
*
Mechatronics
Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics, ...
and
robotics
Robotics is an interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist humans. Robotics integrat ...
*
Engineering design
The engineering design process is a common series of steps that engineers use in creating functional products and processes. The process is highly iterative - parts of the process often need to be repeated many times before another can be entere ...
and
product design
*
Drafting,
computer-aided design (CAD) and
computer-aided manufacturing
Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...
(CAM)
Mechanical engineers are also expected to understand and be able to apply basic concepts from chemistry, physics,
tribology
Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear. Tribology is highly interdisciplinary, drawing on many academic f ...
,
chemical engineering
Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials int ...
,
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage ...
, and
electrical engineering. All mechanical engineering programs include multiple semesters of mathematical classes including calculus, and advanced mathematical concepts including
differential equations,
partial differential equations
In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function.
The function is often thought of as an "unknown" to be solved for, similarly to ...
,
linear algebra
Linear algebra is the branch of mathematics concerning linear equations such as:
:a_1x_1+\cdots +a_nx_n=b,
linear maps such as:
:(x_1, \ldots, x_n) \mapsto a_1x_1+\cdots +a_nx_n,
and their representations in vector spaces and through matrices ...
,
abstract algebra
In mathematics, more specifically algebra, abstract algebra or modern algebra is the study of algebraic structures. Algebraic structures include group (mathematics), groups, ring (mathematics), rings, field (mathematics), fields, module (mathe ...
, and
differential geometry
Differential geometry is a mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds. It uses the techniques of differential calculus, integral calculus, linear algebra and multili ...
, among others.
In addition to the core mechanical engineering curriculum, many mechanical engineering programs offer more specialized programs and classes, such as
control systems
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial c ...
, robotics,
transport
Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...
and
logistics
Logistics is generally the detailed organization and implementation of a complex operation. In a general business sense, logistics manages the flow of goods between the point of origin and the point of consumption to meet the requirements of ...
,
cryogenics
In physics, cryogenics is the production and behaviour of materials at very low temperatures.
The 13th IIR International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of “cryogenics” and “cr ...
,
fuel technology,
automotive engineering,
biomechanics
Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to organs, cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of ...
, vibration,
optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...
and others, if a separate department does not exist for these subjects.
Most mechanical engineering programs also require varying amounts of research or community projects to gain practical problem-solving experience. In the United States it is common for mechanical engineering students to complete one or more
internship
An internship is a period of work experience offered by an organization for a limited period of time. Once confined to medical graduates, internship is used practice for a wide range of placements in businesses, non-profit organizations and gover ...
s while studying, though this is not typically mandated by the university.
Cooperative education
Cooperative education (or co-operative education) is a structured method of combining classroom-based education with practical work experience. A cooperative education experience, commonly known as a "co-op", provides academic credit for struct ...
is another option. Future work skills research puts demand on study components that feed student's creativity and innovation.
Job duties
Mechanical engineers research, design, develop, build, and test mechanical and thermal devices, including tools, engines, and machines.
Mechanical engineers typically do the following:
* Analyze problems to see how mechanical and thermal devices might help solve the problem.
* Design or redesign mechanical and thermal devices using analysis and computer-aided design.
* Develop and test prototypes of devices they design.
* Analyze the test results and change the design as needed.
* Oversee the manufacturing process for the device.
* Manage a team of professionals in specialized fields like mechanical drafting and designing, prototyping, 3D printing or/and CNC Machines specialists.
Mechanical engineers design and oversee the manufacturing of many products ranging from medical devices to new batteries. They also design power-producing machines such as electric generators, internal combustion engines, and steam and gas turbines as well as power-using machines, such as refrigeration and air-conditioning systems.
Like other engineers, mechanical engineers use computers to help create and analyze designs, run simulations and test how a machine is likely to work.
License and regulation
Engineers may seek
license by a state, provincial, or national government. The purpose of this process is to ensure that engineers possess the necessary technical knowledge, real-world experience, and knowledge of the local legal system to practice engineering at a professional level. Once certified, the engineer is given the title of
Professional Engineer
Regulation and licensure in engineering is established by various jurisdictions of the world to encourage life, public welfare, safety, well-being, then environment and other interests of the general public and to define the licensure process thro ...
(United States, Canada, Japan, South Korea, Bangladesh and South Africa),
Chartered Engineer
Regulation and licensure in engineering is established by various jurisdictions of the world to encourage life, public welfare, safety, well-being, then environment and other interests of the general public and to define the licensure process thr ...
(in the United Kingdom, Ireland, India and Zimbabwe), ''Chartered Professional Engineer'' (in Australia and New Zealand) or ''European Engineer'' (much of the European Union).
In the U.S., to become a licensed Professional Engineer (PE), an engineer must pass the comprehensive FE (Fundamentals of Engineering) exam, work a minimum of 4 years as an ''Engineering Intern (EI)'' or ''Engineer-in-Training (EIT)'', and pass the "Principles and Practice" or PE (Practicing Engineer or Professional Engineer) exams. The requirements and steps of this process are set forth by the
National Council of Examiners for Engineering and Surveying
The National Council of Examiners for Engineering and Surveying (NCEES) is an American non-profit organization dedicated to advancing professional licensure for engineers and surveyors. The Council’s members are the engineering and surveying lic ...
(NCEES), composed of engineering and land surveying licensing boards representing all U.S. states and territories.
In the UK, current graduates require a
BEng
A Bachelor of Engineering (BEng) or a Bachelor of Science in Engineering (BSE) is an academic undergraduate degree awarded to a student after three to five years of studying engineering at an accredited college or university.
In the UK, a Bache ...
plus an appropriate master's degree or an integrated
MEng
Meng may refer to:
* Meng (surname) (孟), a Chinese surname
* Master of Engineering (MEng or M.Eng.), an academic or professional master's degree in the field of engineering
* , "M with hook", letter used in the International Phonetic Alphabet
* ...
degree, a minimum of 4 years post graduate on the job competency development and a peer reviewed project report to become a Chartered Mechanical Engineer (CEng, MIMechE) through the
Institution of Mechanical Engineers
The Institution of Mechanical Engineers (IMechE) is an independent professional association and learned society headquartered in London, United Kingdom, that represents mechanical engineers and the engineering profession. With over 120,000 member ...
. CEng MIMechE can also be obtained via an examination route administered by the
City and Guilds of London Institute
The City and Guilds of London Institute is an educational organisation in the United Kingdom. Founded on 11 November 1878 by the City of London and 16 livery companies – to develop a national system of technical education, the institute has ...
.
In most developed countries, certain engineering tasks, such as the design of bridges, electric power plants, and chemical plants, must be approved by a
professional engineer
Regulation and licensure in engineering is established by various jurisdictions of the world to encourage life, public welfare, safety, well-being, then environment and other interests of the general public and to define the licensure process thro ...
or a
chartered engineer
Regulation and licensure in engineering is established by various jurisdictions of the world to encourage life, public welfare, safety, well-being, then environment and other interests of the general public and to define the licensure process thr ...
. "Only a licensed engineer, for instance, may prepare, sign, seal and submit engineering plans and drawings to a public authority for approval, or to seal engineering work for public and private clients." This requirement can be written into state and provincial legislation, such as in the Canadian provinces, for example the Ontario or Quebec's Engineer Act.
In other countries, such as Australia, and the UK, no such legislation exists; however, practically all certifying bodies maintain a
code of ethics
Ethical codes are adopted by organizations to assist members in understanding the difference between right and wrong and in applying that understanding to their decisions. An ethical code generally implies documents at three levels: codes of bus ...
independent of legislation, that they expect all members to abide by or risk expulsion.
Salaries and workforce statistics
The total number of engineers employed in the U.S. in 2015 was roughly 1.6 million. Of these, 278,340 were mechanical engineers (17.28%), the largest discipline by size. In 2012, the median annual income of mechanical engineers in the U.S. workforce was $80,580. The median income was highest when working for the government ($92,030), and lowest in education ($57,090). In 2014, the total number of mechanical engineering jobs was projected to grow 5% over the next decade. As of 2009, the average starting salary was $58,800 with a bachelor's degree.
Subdisciplines
The field of mechanical engineering can be thought of as a collection of many mechanical engineering science disciplines. Several of these subdisciplines which are typically taught at the undergraduate level are listed below, with a brief explanation and the most common application of each. Some of these subdisciplines are unique to mechanical engineering, while others are a combination of mechanical engineering and one or more other disciplines. Most work that a mechanical engineer does uses skills and techniques from several of these subdisciplines, as well as specialized subdisciplines. Specialized subdisciplines, as used in this article, are more likely to be the subject of graduate studies or on-the-job training than undergraduate research. Several specialized subdisciplines are discussed in this section.
Mechanics
![Mohrs circle](https://upload.wikimedia.org/wikipedia/commons/d/d6/Mohrs_circle.svg)
Mechanics is, in the most general sense, the study of
force
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a p ...
s and their effect upon
matter
In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic part ...
. Typically, engineering mechanics is used to analyze and predict the acceleration and deformation (both
elastic
Elastic is a word often used to describe or identify certain types of elastomer, elastic used in garments or stretchable fabrics.
Elastic may also refer to:
Alternative name
* Rubber band, ring-shaped band of rubber used to hold objects togeth ...
and
plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
) of objects under known forces (also called loads) or
stresses. Subdisciplines of mechanics include
*
Statics, the study of non-moving bodies under known loads, how forces affect static bodies
*
Dynamics the study of how forces affect moving bodies. Dynamics includes kinematics (about movement, velocity, and acceleration) and kinetics (about forces and resulting accelerations).
*
Mechanics of materials, the study of how different materials deform under various types of stress
*
Fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them.
It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and ...
, the study of how fluids react to forces
*
Kinematics, the study of the motion of bodies (objects) and systems (groups of objects), while ignoring the forces that cause the motion. Kinematics is often used in the design and analysis of
mechanisms.
*
Continuum mechanics, a method of applying mechanics that assumes that objects are continuous (rather than
discrete
Discrete may refer to:
*Discrete particle or quantum in physics, for example in quantum theory
*Discrete device, an electronic component with just one circuit element, either passive or active, other than an integrated circuit
*Discrete group, a g ...
)
Mechanical engineers typically use mechanics in the design or analysis phases of engineering. If the engineering project were the design of a vehicle, statics might be employed to design the frame of the vehicle, in order to evaluate where the stresses will be most intense. Dynamics might be used when designing the car's engine, to evaluate the forces in the
pistons and
cam
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the bin ...
s as the engine cycles. Mechanics of materials might be used to choose appropriate materials for the frame and engine. Fluid mechanics might be used to design a ventilation system for the vehicle (see
HVAC), or to design the
intake
An intake (also inlet) is an opening, structure or system through which a fluid is admitted to a space or machine as a consequence of a pressure differential between the outside and the inside. The pressure difference may be generated on the ins ...
system for the engine.
Mechatronics and robotics
![FMS1 small](https://upload.wikimedia.org/wikipedia/commons/4/4c/FMS1_small.JPG)
Mechatronics is a combination of mechanics and electronics. It is an interdisciplinary branch of mechanical engineering,
electrical engineering and
software engineering
Software engineering is a systematic engineering approach to software development.
A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term '' ...
that is concerned with integrating electrical and mechanical engineering to create hybrid automation systems. In this way, machines can be automated through the use of
electric motor
An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...
s,
servo-mechanisms, and other electrical systems in conjunction with special software. A common example of a mechatronics system is a CD-ROM drive. Mechanical systems open and close the drive, spin the CD and move the laser, while an optical system reads the data on the CD and converts it to
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s. Integrated software controls the process and communicates the contents of the CD to the computer.
Robotics is the application of mechatronics to create robots, which are often used in industry to perform tasks that are dangerous, unpleasant, or repetitive. These robots may be of any shape and size, but all are preprogrammed and interact physically with the world. To create a robot, an engineer typically employs kinematics (to determine the robot's range of motion) and mechanics (to determine the stresses within the robot).
Robots are used extensively in industrial automation engineering. They allow businesses to save money on labor, perform tasks that are either too dangerous or too precise for humans to perform them economically, and to ensure better quality. Many companies employ
assembly lines
An assembly line is a manufacturing process (often called a ''progressive assembly'') in which parts (usually interchangeable parts) are added as the semi-finished assembly moves from workstation to workstation where the parts are added in sequ ...
of robots, especially in Automotive Industries and some factories are so robotized that they can run
by themselves. Outside the factory, robots have been employed in bomb disposal,
space exploration, and many other fields. Robots are also sold for various residential applications, from recreation to domestic applications.
Structural analysis
Structural analysis is the branch of mechanical engineering (and also civil engineering) devoted to examining why and how objects fail and to fix the objects and their performance. Structural failures occur in two general modes: static failure, and fatigue failure. ''Static structural failure'' occurs when, upon being loaded (having a force applied) the object being analyzed either breaks or is deformed
plastically, depending on the criterion for failure. ''Fatigue failure'' occurs when an object fails after a number of repeated loading and unloading cycles. Fatigue failure occurs because of imperfections in the object: a microscopic crack on the surface of the object, for instance, will grow slightly with each cycle (propagation) until the crack is large enough to cause
ultimate failure
In mechanical engineering, ultimate failure describes the breaking of a material. In general there are two types of failure: fracture and buckling. Fracture of a material occurs when either an internal or external crack elongates the width or len ...
.
Failure is not simply defined as when a part breaks, however; it is defined as when a part does not operate as intended. Some systems, such as the perforated top sections of some plastic bags, are designed to break. If these systems do not break, failure analysis might be employed to determine the cause.
Structural analysis is often used by mechanical engineers after a failure has occurred, or when designing to prevent failure. Engineers often use online documents and books such as those published by ASM to aid them in determining the type of failure and possible causes.
Once theory is applied to a mechanical design, physical testing is often performed to verify calculated results. Structural analysis may be used in an office when designing parts, in the field to analyze failed parts, or in laboratories where parts might undergo controlled failure tests.
Thermodynamics and thermo-science
Thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of th ...
is an applied science used in several branches of engineering, including mechanical and chemical engineering. At its simplest, thermodynamics is the study of energy, its use and transformation through a
system. Typically, engineering thermodynamics is concerned with changing energy from one form to another. As an example, automotive engines convert chemical energy (
enthalpy
Enthalpy , a property of a thermodynamic system, is the sum of the system's internal energy and the product of its pressure and volume. It is a state function used in many measurements in chemical, biological, and physical systems at a constant ...
) from the fuel into heat, and then into mechanical work that eventually turns the wheels.
Thermodynamics principles are used by mechanical engineers in the fields of
heat transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
,
thermofluids
Thermofluids is a branch of science and engineering encompassing four intersecting fields:
*Heat transfer
*Thermodynamics
*Fluid mechanics
*Combustion
The term is a combination of "thermo", referring to heat, and "fluids", which refers to liquids ...
, and
energy conversion
Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work or moving, (e.g. Lifting an object) or provides heat ...
. Mechanical engineers use thermo-science to design
engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...
s and
power plant
A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an el ...
s, heating, ventilation, and air-conditioning (HVAC) systems,
heat exchanger
A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct conta ...
s,
heat sink
A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, th ...
s,
radiators,
refrigeration
The term refrigeration refers to the process of removing heat from an enclosed space or substance for the purpose of lowering the temperature.International Dictionary of Refrigeration, http://dictionary.iifiir.org/search.phpASHRAE Terminology, ht ...
,
insulation
Insulation may refer to:
Thermal
* Thermal insulation, use of materials to reduce rates of heat transfer
** List of insulation materials
** Building insulation, thermal insulation added to buildings for comfort and energy efficiency
*** Insulated ...
, and others.
Design and drafting
Drafting or technical drawing is the means by which mechanical engineers design products and create instructions for
manufacturing
Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to ...
parts. A technical drawing can be a computer model or hand-drawn schematic showing all the dimensions necessary to manufacture a part, as well as assembly notes, a list of required materials, and other pertinent information. A U.S. mechanical engineer or skilled worker who creates technical drawings may be referred to as a drafter or draftsman. Drafting has historically been a two-dimensional process, but
computer-aided design (CAD) programs now allow the designer to create in three dimensions.
Instructions for manufacturing a part must be fed to the necessary machinery, either manually, through programmed instructions, or through the use of a
computer-aided manufacturing
Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...
(CAM) or combined CAD/CAM program. Optionally, an engineer may also manually manufacture a part using the technical drawings. However, with the advent of
computer numerically controlled (CNC) manufacturing, parts can now be fabricated without the need for constant technician input. Manually manufactured parts generally consist of
spray coatings, surface finishes, and other processes that cannot economically or practically be done by a machine.
Drafting is used in nearly every subdiscipline of mechanical engineering, and by many other branches of engineering and architecture. Three-dimensional models created using CAD software are also commonly used in
finite element analysis
The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...
(FEA) and
computational fluid dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate th ...
(CFD).
Modern tools
![cad crank](https://upload.wikimedia.org/wikipedia/commons/d/dc/Cad_crank.jpg)
Many mechanical engineering companies, especially those in industrialized nations, have begun to incorporate
computer-aided engineering
Computer-aided engineering (CAE) is the broad usage of computer software to aid in engineering analysis tasks. It includes , , , durability and optimization. It is included with computer-aided design (CAD) and computer-aided manufacturing (CAM) ...
(CAE) programs into their existing design and analysis processes, including 2D and 3D
solid modeling
Solid modeling (or solid modelling) is a consistent set of principles for mathematical and computer modeling of three-dimensional shapes '' (solids)''. Solid modeling is distinguished from related areas of geometric modeling and computer graphi ...
computer-aided design (CAD). This method has many benefits, including easier and more exhaustive visualization of products, the ability to create virtual assemblies of parts, and the ease of use in designing mating interfaces and tolerances.
Other CAE programs commonly used by mechanical engineers include
product lifecycle management
In industry, Product Lifecycle Management (PLM) is the process of managing the entire lifecycle of a product from its inception through the engineering, design and manufacture, as well as the service and disposal of manufactured products. PL ...
(PLM) tools and analysis tools used to perform complex simulations. Analysis tools may be used to predict product response to expected loads, including fatigue life and manufacturability. These tools include
finite element analysis
The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...
(FEA),
computational fluid dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate th ...
(CFD), and
computer-aided manufacturing
Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...
(CAM).
Using CAE programs, a mechanical design team can quickly and cheaply iterate the design process to develop a product that better meets cost, performance, and other constraints. No physical prototype need be created until the design nears completion, allowing hundreds or thousands of designs to be evaluated, instead of a relative few. In addition, CAE analysis programs can model complicated physical phenomena which cannot be solved by hand, such as
viscoelasticity
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearl ...
, complex contact between mating parts, or
non-Newtonian flows.
As mechanical engineering begins to merge with other disciplines, as seen in
mechatronics
Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics, ...
,
multidisciplinary design optimization
Multi-disciplinary design optimization (MDO) is a field of engineering that uses optimization methods to solve design problems incorporating a number of disciplines. It is also known as multidisciplinary system design optimization (MSDO), and Multi ...
(MDO) is being used with other CAE programs to automate and improve the iterative design process. MDO tools wrap around existing CAE processes, allowing product evaluation to continue even after the analyst goes home for the day. They also use sophisticated optimization algorithms to more intelligently explore possible designs, often finding better, innovative solutions to difficult multidisciplinary design problems.
Areas of research
Mechanical engineers are constantly pushing the boundaries of what is physically possible in order to produce safer, cheaper, and more efficient machines and mechanical systems. Some technologies at the cutting edge of mechanical engineering are listed below (see also
exploratory engineering
Exploratory engineering is a term coined by K. Eric Drexler to describe the process of designing and analyzing detailed hypothetical models of systems that are not feasible with current technologies or methods, but do seem to be clearly within th ...
).
Micro electro-mechanical systems (MEMS)
Micron-scale mechanical components such as springs, gears, fluidic and heat transfer devices are fabricated from a variety of substrate materials such as silicon, glass and polymers like
SU8
SU-8 is a commonly used epoxy-based negative photoresist. Negative refers to a photoresist whereby the parts exposed to UV become cross-linked, while the remainder of the film remains soluble and can be washed away during development.
As show ...
. Examples of
MEMS
Microelectromechanical systems (MEMS), also written as micro-electro-mechanical systems (or microelectronic and microelectromechanical systems) and the related micromechatronics and microsystems constitute the technology of microscopic devices, ...
components are the accelerometers that are used as car airbag sensors, modern cell phones, gyroscopes for precise positioning and microfluidic devices used in biomedical applications.
Friction stir welding (FSW)
Friction stir welding, a new type of
welding
Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as bra ...
, was discovered in 1991 by
The Welding Institute
The Welding Institute (TWI Ltd) is a research and technology organisation, with a specialty in welding. It has had headquarters near Cambridge, England, since 1946, and has other facilities across the UK and around the world. TWI works across ...
(TWI). The innovative steady state (non-fusion) welding technique joins materials previously un-weldable, including several
aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...
alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
s. It plays an important role in the future construction of airplanes, potentially replacing rivets. Current uses of this technology to date include welding the seams of the aluminum main Space Shuttle external tank, Orion Crew Vehicle, Boeing Delta II and Delta IV Expendable Launch Vehicles and the
SpaceX
Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...
Falcon 1 rocket, armor plating for amphibious assault ships, and welding the wings and fuselage panels of the new Eclipse 500 aircraft from Eclipse Aviation among an increasingly growing pool of uses.
Composites
![Kohlenstofffasermatte](https://upload.wikimedia.org/wikipedia/commons/4/44/Kohlenstofffasermatte.jpg)
Composites or composite materials are a combination of materials which provide different physical characteristics than either material separately. Composite material research within mechanical engineering typically focuses on designing (and, subsequently, finding applications for) stronger or more rigid materials while attempting to reduce
weight
In science and engineering, the weight of an object is the force acting on the object due to gravity.
Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar qua ...
, susceptibility to corrosion, and other undesirable factors. Carbon fiber reinforced composites, for instance, have been used in such diverse applications as spacecraft and fishing rods.
Mechatronics
Mechatronics
Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics, ...
is the synergistic combination of mechanical engineering,
electronic engineering
Electronics engineering is a sub-discipline of electrical engineering which emerged in the early 20th century and is distinguished by the additional use of active components such as semiconductor devices to amplify and control electric current ...
, and software engineering. The discipline of mechatronics began as a way to combine mechanical principles with electrical engineering. Mechatronic concepts are used in the majority of electro-mechanical systems. Typical electro-mechanical sensors used in mechatronics are strain gauges, thermocouples, and pressure transducers.
Nanotechnology
At the smallest scales, mechanical engineering becomes nanotechnology—one speculative goal of which is to create a
molecular assembler
A molecular assembler, as defined by K. Eric Drexler, is a "proposed device able to guide chemical reactions by positioning reactive molecules with atomic precision". A molecular assembler is a kind of molecular machine. Some biological molecul ...
to build molecules and materials via
mechanosynthesis
Mechanosynthesis is a term for hypothetical chemical syntheses in which reaction outcomes are determined by the use of mechanical constraints to direct reactive molecules to specific molecular sites. There are presently no non-biological chemica ...
. For now that goal remains within
exploratory engineering
Exploratory engineering is a term coined by K. Eric Drexler to describe the process of designing and analyzing detailed hypothetical models of systems that are not feasible with current technologies or methods, but do seem to be clearly within th ...
. Areas of current mechanical engineering research in nanotechnology include nanofilters, nanofilms, and nanostructures, among others.
Finite element analysis
Finite Element Analysis is a computational tool used to estimate stress, strain, and deflection of solid bodies. It uses a mesh setup with user-defined sizes to measure physical quantities at a node. The more nodes there are, the higher the precision. This field is not new, as the basis of Finite Element Analysis (FEA) or Finite Element Method (FEM) dates back to 1941. But the evolution of computers has made FEA/FEM a viable option for analysis of structural problems. Many commercial codes such as
NASTRAN
NASTRAN is a finite element analysis (FEA) program that was originally developed for NASA in the late 1960s under United States government funding for the aerospace industry. The MacNeal-Schwendler Corporation (MSC) was one of the principal and o ...
,
ANSYS, and
ABAQUS
Abaqus FEA (formerly ABAQUS) is a software suite for finite element analysis and computer-aided engineering, originally released in 1978. The name and logo of this software are based on the abacus calculation tool.
The Abaqus product suite consis ...
are widely used in industry for research and the design of components. Some 3D modeling and CAD software packages have added FEA modules. In the recent times, cloud simulation platforms like
SimScale
SimScale is a computer-aided engineering (CAE) software product based on cloud computing. SimScale was developed by SimScale GmbH and allows computational fluid dynamics, finite element analysis and thermal simulations. The backend of the platf ...
are becoming more common.
Other techniques such as finite difference method (FDM) and finite-volume method (FVM) are employed to solve problems relating heat and mass transfer, fluid flows, fluid surface interaction, etc.
Biomechanics
Biomechanics is the application of mechanical principles to biological systems, such as
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s,
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s,
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...
s,
organs
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a f ...
, and
cells. Biomechanics also aids in creating prosthetic limbs and artificial organs for humans. Biomechanics is closely related to
engineering
Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...
, because it often uses traditional engineering sciences to analyze biological systems. Some simple applications of
Newtonian mechanics and/or
materials sciences can supply correct approximations to the mechanics of many biological systems.
In the past decade, reverse engineering of materials found in nature such as bone matter has gained funding in academia. The structure of bone matter is optimized for its purpose of bearing a large amount of compressive stress per unit weight. The goal is to replace crude steel with bio-material for structural design.
Over the past decade the
Finite element method
The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...
(FEM) has also entered the Biomedical sector highlighting further engineering aspects of Biomechanics. FEM has since then established itself as an alternative to
in vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...
surgical assessment and gained the wide acceptance of academia. The main advantage of Computational Biomechanics lies in its ability to determine the endo-anatomical response of an anatomy, without being subject to ethical restrictions. This has led FE modelling to the point of becoming ubiquitous in several fields of Biomechanics while several projects have even adopted an open source philosophy (e.g. BioSpine).
Computational fluid dynamics
Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as turbulent flows. Initial validation of such software is performed using a wind tunnel with the final validation coming in full-scale testing, e.g. flight tests.
Acoustical engineering
Acoustical engineering is one of many other sub-disciplines of mechanical engineering and is the application of acoustics. Acoustical engineering is the study of
Sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the ...
and
Vibration
Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic, such as the motion of a pendulum—or random, su ...
. These engineers work effectively to reduce
noise pollution
Noise pollution, also known as environmental noise or sound pollution, is the propagation of noise with ranging impacts on the activity of human or animal life, most of them are harmful to a degree. The source of outdoor noise worldwide is ma ...
in mechanical devices and in buildings by soundproofing or removing sources of unwanted noise. The study of acoustics can range from designing a more efficient hearing aid, microphone, headphone, or recording studio to enhancing the sound quality of an orchestra hall. Acoustical engineering also deals with the vibration of different mechanical systems.
Related fields
Manufacturing engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
,
aerospace engineering and
automotive engineering are grouped with mechanical engineering at times. A bachelor's degree in these areas will typically have a difference of a few specialized classes.
See also
*
Index of mechanical engineering articles
; Lists
*
Glossary of mechanical engineering
''Most of the terms listed in Wikipedia glossaries are already defined and explained within Wikipedia itself. However, glossaries like this one are useful for looking up, comparing and reviewing large numbers of terms together. You can help enhan ...
*
List of historic mechanical engineering landmarks
*
List of inventors
This is a list of notable inventors.
Alphabetical list
A
* Vitaly Abalakov (1906–1986), Russia – camming devices, Abalakov thread (or V-thread), gearless ice climbing anchor
* Ernst Karl Abbe (1840–1905), Germany – Condenser (micros ...
*
List of mechanical engineering topics
This is an alphabetical list of articles pertaining specifically to mechanical engineering. For a broad overview of engineering, please see List of engineering topics. For biographies please see List of engineers.
A
Acceleration –
Accuracy an ...
*
List of mechanical engineers
This is a list of mechanical engineers, noted for their contribution to the field of mechanical engineering.
See also List of engineers for links to other engineering professions.
__NOTOC__
A
* Ahmed Zulfikar (1952–2010) – Entrepreneur an ...
*
List of related journals
*
List of mechanical, electrical and electronic equipment manufacturing companies by revenue
; Associations
*
(ASHRAE)
*
American Society of Mechanical Engineers (ASME)
*
Pi Tau Sigma
Pi Tau Sigma () is an international honor society in the field of mechanical engineering, with most chapters established in the United States. It honors mechanical engineering students who have exemplified the "principles of scholarship, characte ...
(Mechanical Engineering honor society)
*
Society of Automotive Engineers
SAE International, formerly named the Society of Automotive Engineers, is a United States-based, globally active professional association and standards developing organization for engineering professionals in various industries. SAE Internatio ...
(SAE)
*
Society of Women Engineers (SWE)
*
Institution of Mechanical Engineers
The Institution of Mechanical Engineers (IMechE) is an independent professional association and learned society headquartered in London, United Kingdom, that represents mechanical engineers and the engineering profession. With over 120,000 member ...
(IMechE) (British)
*
Chartered Institution of Building Services Engineers
The Chartered Institution of Building Services Engineers (CIBSE; pronounced 'sib-see') is an international professional engineering association based in London, England that represents building services engineers. It is a full member of the C ...
(CIBSE) (British)
*
Verein Deutscher Ingenieure
Verein Deutscher Ingenieure (VDI) (English: Association of German Engineers) is an organization of over 150,000 engineers and natural scientists. More than 12,000 honorary experts process the latest technical findings each year to promote the techn ...
(VDI) (Germany)
; Wikibooks
*
Engineering Mechanics
Applied mechanics is the branch of science concerned with the motion of any substance that can be experienced or perceived by humans without the help of instruments. In short, when mechanics concepts surpass being theoretical and are applied and e ...
*
Engineering Thermodynamics
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
*
Engineering Acoustics
*
Fluid Mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them.
It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and ...
*
Heat Transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
*
Microtechnology
Microtechnology deals with technology whose features have dimensions of the order of one micrometre (one millionth of a metre, or 10−6 metre, or 1μm). It focuses on physical and chemical processes as well as the production or manipulation of str ...
*
Nanotechnology
*
Pro/Engineer (ProE CAD)
*
Strength of Materials/Solid Mechanics
References
Further reading
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*
External links
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{{Authority control
Engineering disciplines
Mechanical designers