DIC法によるポリカーボネイトおよびABS材の変形の局所化現象の解明と局所化部周辺の硬さによる強度評価

抄録

It is a well-known fact that there is significant difference in magnitude of flow stresses and work hardening rates of Polycarbonate and ABS between in tension and compression. There is a possibility that hydrostatic pressure is involved in this asymmetry to the loading axis, in which case volume change occurs in plastic deformation. The aim of this study is to measure the variation of plastic Poisson’s ratio by means of Digital Image Correlation method to clarify the existence of the plastic compressibility of Polycarbonate and ABS. The authors conducted tensile tests of thin strip specimens, and measured the axial and lateral strains by DIC method, then, plastic Poisson's ratio was derived. The result showed that plastic Poisson’s ratio of Polycarbonate was smaller than the value of 0.5, that result in the existence of plastic compressibility in this material. The Vickers hardness measurement for a gauge length was also performed to clarify the strength distribution of a specimen, and the results showed that the necking part of the materials was softened.