Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 97 === The specimens are in the form of a thin plate and subjected to a plane stress loading. The timing and intensity of any kind of toughening mechanisms have been observed when the specimen is subjected to the tensile-compressive or simple tension cyclic loadings. Instantaneous bulk modulus, instantaneous Poisson’s ratio and instantaneous Young’s modulus are derived from the recorded stress-strain curves. Then those instantaneous mechanical properties are compared with those in linear elastic deformation to analyze the occurring intensity of various kind of inelastic deformation, such as phase transformation and domain reorientation.
It has been shown that substantial inelastic deformation, especially phase transformation and its reverse deformation, occurs in the alternating tensile-compressive loadings. The intensity of this kind of toughening mechanism in this alternating loading is much higher than that in pure tension or compression.
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