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VocabularyVocabulary bar— брусок, прут compression — сжатие creep — ползучесть cross-sectional area — площадь поперечного сечения cyclic stress — циклическое напряжение decrease — уменьшение elastic deformation — упругая деформация elastic limit — предел упругости exceed — превышать external forces — внешние силы fracture — перелом, излом loosen — ослаблять, расшатывать permanent deformation — постоянная деформация remaining — оставшийся shear — срез simultaneously — одновременно technique — методы tension — напряженность to propagate — распространяться to meet the needs — отвечать требованиям to occur — происходить to respond — отвечать реагировать torsion — кручение twisting — закручивание, изгиб volume — объем, количество rupture — разрыв Materials Science and Technology is the study of materials and how they can be fabricatedto meet the needsof modern technology. Using the laboratorytechniquesand knowledge of physics, chemistry, and metallurgy, scientists are finding new ways of using metals, plastics and other materials. Engineers must know how materialsrespond to external forces, such astension, compression, torsion, bending, and shear. All materials respond to these forces by elastic deformation. That is, the materials return their original size and form when theexternal force disappears. The materials may also havepermanent deformation or they mayfracture. The results of external forces arecreep andfatigue. Compression isa pressure causing adecrease in volume. When a material is subjected to abending, shearing, or torsion (twisting) force, both tensile and compressive forces aresimultaneously at work. When a metal bar is bent, one side of it is stretched and subjected to a tensional force, and the other side is compressed.
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