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Prestressed Structure
In structural engineering, a prestressed structure is a load-bearing structure whose overall integrity, stability and security depend, primarily, on ''prestressing'': the intentional creation of permanent stresses in the structure for the purpose of improving its performance under various service conditions. The basic types of prestressing are: *Precompression with mostly the structure's own weight *Pre-tensioning with high-strength embedded tendons *Post-tensioning with high-strength bonded or unbonded tendons Today, the concept of a prestressed structure is widely employed in the design of buildings, underground structures, TV towers, power stations, floating storage and offshore facilities, nuclear reactor vessels, and numerous bridge systems. It is especially prominent in construction using concrete (see pre-stressed concrete). The idea of precompression was apparently familiar to ancient Roman architects. The tall attic wall of the Colosseum The Colosseum ( ; , ul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Colosseum With Moon
Roman or Romans most often refers to: *Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of Roman civilization *Epistle to the Romans, shortened to Romans, a letter written by Paul, found in the New Testament of the Christian Bible * Ar-Rum (), the 30th sura of the Quran. Roman or Romans may also refer to: Arts and entertainment Music * Romans (band), a Japanese pop group * ''Roman'' (album), by Sound Horizon, 2006 * ''Roman'' (EP), by Teen Top, 2011 *" Roman (My Dear Boy)", a 2004 single by Morning Musume Film and television *Film Roman, an American animation studio * ''Roman'' (film), a 2006 American suspense-horror film * ''Romans'' (2013 film), an Indian Malayalam comedy film * ''Romans'' (2017 film), a British drama film * ''The Romans'' (''Doctor Who''), a serial in British TV series People * Roman (given name), a given name, including a list of people and fictional characters *Roman (surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Engineering
Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and joints' that create the form and shape of human-made Structure#Load-bearing, structures. Structural engineers also must understand and calculate the structural stability, stability, strength, structural rigidity, rigidity and earthquake-susceptibility of built structures for buildings and nonbuilding structures. The structural designs are integrated with those of other designers such as architects and Building services engineering, building services engineer and often supervise the construction of projects by contractors on site. They can also be involved in the design of machinery, medical equipment, and vehicles where structural integrity affects functioning and safety. See glossary of structural engineering. Structural engineering theory is based upon applied physics, physical laws and empirical knowledge of the structural performance of different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals. Abstract structures include data structures in computer science and musical form. Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links, or a lattice featuring connections between components that are neighbors in space. Load-bearing Buildings, aircraft, skeletons, anthills, beaver dams, bridges and salt domes are all examples of load-bearing structures. The results of construction are divided into buildings and non-building structures, and make up the infrastructure of a human society. Built structures are broadly divided by their varying design approaches and standards, into categories including building struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Integrity And Failure
Structural integrity and failure is an aspect of engineering that deals with the ability of a structure to support a designed structural load (weight, force, etc.) without breaking and includes the study of past structural failures in order to prevent failures in future designs. Structural integrity is the ability of an item—either a structural component or a structure consisting of many components—to hold together under a load, including its own weight, without breaking or deforming excessively. It assures that the construction will perform its designed function during reasonable use, for as long as its intended life span. Items are constructed with structural integrity to prevent catastrophic failure, which can result in injuries, severe damage, death, and/or monetary losses. ''Structural failure'' refers to the loss of structural integrity, or the loss of load-carrying structural capacity in either a structural component or the structure itself. Structural failure is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Stability
In mathematics, structural stability is a fundamental property of a dynamical system which means that the qualitative behavior of the trajectories is unaffected by small perturbations (to be exact ''C''1-small perturbations). Examples of such qualitative properties are numbers of fixed points and periodic orbits (but not their periods). Unlike Lyapunov stability, which considers perturbations of initial conditions for a fixed system, structural stability deals with perturbations of the system itself. Variants of this notion apply to systems of ordinary differential equations, vector fields on smooth manifolds and flows generated by them, and diffeomorphisms. Structurally stable systems were introduced by Aleksandr Andronov and Lev Pontryagin in 1937 under the name "systèmes grossiers", or rough systems. They announced a characterization of rough systems in the plane, the Andronov–Pontryagin criterion. In this case, structurally stable systems are ''typical'', they form an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress (mechanics)
In continuum mechanics, stress is a physical quantity that describes forces present during deformation. For example, an object being pulled apart, such as a stretched elastic band, is subject to ''tensile'' stress and may undergo elongation. An object being pushed together, such as a crumpled sponge, is subject to ''compressive'' stress and may undergo shortening. The greater the force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Stress has dimension of force per area, with SI units of newtons per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while ''strain'' is the measure of the relative deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushes on the particles immediately below it. When a liquid is in a closed container under pressure, each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building
A building or edifice is an enclosed Structure#Load-bearing, structure with a roof, walls and window, windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for numerous factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, monument, prestige, and aesthetic reasons. To better understand the concept, see ''Nonbuilding structure'' for contrast. Buildings serve several societal needs – occupancy, primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical separation of the :Human habitats, human habitat (a place of comfort and safety) from the ''outside'' (a place that may be harsh and harmful at times). buildings have been objects or canvasses of much architecture, artistic expression. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reactor
A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons production and Research reactor, research. Fissile material, Fissile nuclei (primarily uranium-235 or plutonium-239) absorb single neutron, neutrons and split, releasing energy and multiple neutrons, which can induce further fission. Reactors stabilize this, regulating Neutron absorber, neutron absorbers and neutron moderator, moderators in the core. Fuel efficiency is exceptionally high; Enriched uranium#Low-enriched uranium (LEU), low-enriched uranium is 120,000 times more energy dense than coal. Heat from nuclear fission is passed to a working fluid Nuclear reactor#By coolant, coolant. In commercial reactors, this drives Turbine, turbines and electrical generator shafts. Some reactors are used for district heating, and isotopes, isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge
A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, the material used to make it, and the funds available to build it. The earliest bridges were likely made with fallen trees and stepping stones. The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge, dating from the 13th century BC, in the Peloponnese is one of the oldest arch bridges in existence and use. Etymology The ''Oxford English Dictionary'' traces the origin of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactured material in the world. When aggregate is mixed with dry Portland cement and water, the mixture forms a fluid slurry that can be poured and molded into shape. The cement reacts with the water through a process called hydration, which hardens it after several hours to form a solid matrix that binds the materials together into a durable stone-like material with various uses. This time allows concrete to not only be cast in forms, but also to have a variety of tooled processes performed. The hydration process is exothermic, which means that ambient temperature plays a significant role in how long it takes concrete to set. Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-stressed Concrete
Prestressed concrete is a form of concrete used in construction. It is substantially prestressed ( compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service. Post-tensioned concreted is "structural concrete in which internal stresses have been introduced to reduce potential tensile stresses in the concrete resulting from loads." It was patented by Eugène Freyssinet in 1928. This compression is produced by the tensioning of high-strength ''tendons'' located within or adjacent to the concrete and is done to improve the performance of the concrete in service. Tendons may consist of single wires, multi-wire strands or threaded bars that are most commonly made from high-tensile steels, carbon fiber or aramid fiber. The essence of prestressed concrete is that once the initial compression has been applied, the resulting material has the characteristics of high-strength concrete when subject to any subsequent compression f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
