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Residual Stress
In materials science and solid mechanics, residual stresses are Stress (physics), stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening imparts deep beneficial compressive residual stresses into metal components such as turbine engine fan blades, and it is used in toughened glass to allow for large, thin, crack- and scratch-resistant glass displays on smartphones. However, unintended residual stress in a designed structure may cause it to Catastrophic failure, fail prematurely. Residual stresses can result from a variety of mechanisms including inelastic (Plasticity (physics), plastic) Deformation (engineering), deformations, temperature gradients (during thermal cycle) or structural changes (phase transformation). Heat from welding may cause localized expansion, which is taken up during welding by either the molten metal or the placement of parts being welde ... [...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." 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 forces and of ductile high-strength steel when subje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macroscopic
The macroscopic scale is the length scale on which objects or phenomena are large enough to be visible with the naked eye, without magnifying optical instruments. It is the opposite of microscopic. Overview When applied to physical phenomena and bodies, the macroscopic scale describes things as a person can directly perceive them, without the aid of magnifying devices. This is in contrast to observations (microscopy) or theories ( microphysics, statistical physics) of objects of geometric lengths smaller than perhaps some hundreds of micrometers. A macroscopic view of a ball is just that: a ball. A microscopic view could reveal a thick round skin seemingly composed entirely of puckered cracks and fissures (as viewed through a microscope) or, further down in scale, a collection of molecules in a roughly spherical shape (as viewed through an electron microscope). An example of a physical theory that takes a deliberately macroscopic viewpoint is thermodynamics. An example of a topi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Residual Stress Measurement Techniques Comparison
A residual is generally a quantity left over at the end of a process. It may refer to: Business * Residual (entertainment industry), in business, one of an ongoing stream of royalties for rerunning or reusing motion pictures, television shows or commercials * Profit (accounting), residuals that shareholders, partners or other owners are entitled to, after debtors are covered **Residual in the bankruptcy of insolvent businesses, moneys that are left after all assets are sold and all creditors paid, to be divided among ''residual claimants'' * Residual (or balloon) in finance, a lump sum owed to the financier at the end of a loan's term; for example Balloon payment mortgage Mathematics, statistics and econometrics * Residual (statistics) ** Studentized residual * Residual time, in the theory of renewal processes * Residual (numerical analysis) ** Minimal residual method ** Generalized minimal residual method * Residual set, the complement of a meager set * Residual property (math ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Example HiFIT-treated Assembly
Example may refer to: * '' exempli gratia'' (e.g.), usually read out in English as "for example" * .example, reserved as a domain name that may not be installed as a top-level domain of the Internet ** example.com, example.net, example.org, example.edu, second-level domain names reserved for use in documentation as examples * HMS ''Example'' (P165), an Archer-class patrol and training vessel of the Royal Navy Arts * ''The Example'', a 1634 play by James Shirley * ''The Example'' (comics), a 2009 graphic novel by Tom Taylor and Colin Wilson * Example (musician), the British dance musician Elliot John Gleave (born 1982) * ''Example'' (album), a 1995 album by American rock band For Squirrels See also * * Exemplar (other), a prototype or model which others can use to understand a topic better * Exemplum, medieval collections of short stories to be told in sermons * Eixample The Eixample (; ) is a district of Barcelona between the old city ( Ciutat Vella) an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Frequency Impact Treatment
The high-frequency impact treatment or HiFIT – Method is the treatment of welded steel constructions at the weld transition to increase the fatigue strength. Features The durability and life of dynamically loaded, welded steel structures is determined in many cases by the welds, in particular the weld transitions. Through selective treatment of the transitions ( grinding (abrasive cutting), abrasive blasting, hammering, etc.), the durability of many designs increase significantly. Hammering methods have proven to be particularly effective treatment methods and were within the joint project REFRESH extensively studied and developed. The HiFIT (High-Frequency Impact Treatment (also called HFMI (High Frequency Mechanical Impact))) process is such a hammering method that is universally applicable, requires only a low tech equipment and still offers high reproducibility and the possibility for quality control. Operation The HiFIT hammer operates with a hardened pin with a ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shot Peening
Shot peening is a cold working process used to produce a compressive residual stress layer and modify the mechanical properties of metals and composites. It entails striking a surface with shot (round metallic, glass, or ceramic particles) with force sufficient to create plastic deformation."Shot Peening," ''Tool and Manufacturing Engineers Handbook'' (TMEH), Volume 3, Society of Manufacturing Engineers, 1985 In machining, shot peening is used to strengthen and relieve stress in components like steel automobile crankshafts and connecting rods. In architecture it provides a muted finish to metal. Shot peening is similar mechanically to sandblasting, though its purpose is not to remove material, but rather it employs the mechanism of plasticity to achieve its goal, with each particle functioning as a ball-peen hammer. Details Peening a surface spreads it plastically, causing changes in the mechanical properties of the surface. Its main application is to avoid the propagation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prince Ruperts Drops
A prince is a male ruler (ranked below a king, grand prince, and grand duke) or a male member of a monarch's or former monarch's family. ''Prince'' is also a title of nobility (often highest), often hereditary, in some European states. The female equivalent is a princess. The English word derives, via the French word ''prince'', from the Latin noun , from (first) and (head), meaning "the first, foremost, the chief, most distinguished, noble ruler, prince". Historical background The Latin word (older Latin *prīsmo-kaps, literally "the one who takes the first lace/position), became the usual title of the informal leader of the Roman senate some centuries before the transition to empire, the '' princeps senatus''. Emperor Augustus established the formal position of monarch on the basis of principate, not dominion. He also tasked his grandsons as summer rulers of the city when most of the government were on holiday in the country or attending religious rituals, and, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katana
A is a Japanese sword characterized by a curved, single-edged blade with a circular or squared guard and long grip to accommodate two hands. Developed later than the ''tachi'', it was used by samurai in feudal Japan and worn with the edge facing upward. Since the Muromachi period, many old ''tachi'' were cut from the root and shortened, and the blade at the root was crushed and converted into ''katana''. The specific term for ''katana'' in Japan is ''uchigatana'' (打刀) and the term ''katana'' (刀) often refers to single-edged swords from around the world. Etymology and loanwords The word ''katana'' first appears in Japanese in the '' Nihon Shoki'' of 720. The term is a compound of ''kata'' ("one side, one-sided") + ''na'' ("blade"), in contrast to the double-sided '' tsurugi''. See more at the Wiktionary entry. The ''katana'' belongs to the ''nihontō'' family of swords, and is distinguished by a blade length (''nagasa'') of more than 2 ''shaku'', approximately . ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. Measuring hardness There are three main types of hardness measurements: ''scratch' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martensite
Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens. By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation. Properties Martensite is formed in carbon steels by the rapid cooling (quenching) of the austenite form of iron at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite (Fe3C). Austenite is gamma-phase iron (γ-Fe), a solid solution of iron and alloying elements. As a result of the quenching, the face-centered cubic austenite transforms to a highly strained body-centered tetragonal form called martensite that is supersaturated with carbon. The shear deformations that result produce a large number of dislocations, which is a primary strengthening mechanism of steels. The highest hardness of a pearlitic steel is 400 Brinell, whereas martensite can achieve 700 Bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
