EVALUATION OF DYNAMIC CONSTITUTIVE RELATION ON PURE COPPER BASED ON EXPERIMENTAL - NUMERICAL ANALYSIS

摘要

A hybrid experimental and computational investigation of dynamic constitutive relationship of annealed pure copper is presented in this paper. A series of experiments based on the split - Hopkinson torsional bar (SHTB) method was executed. In the present experiments shear strain of a thin walled tubular specimen is evaluated in two manners; one is nominal shear strain which is obtained from incidcnt and transmitted waves on elastic bars and another is direct shear strain which is measured by strain gages cemented on the specimen. The nominal shear strains of the specimens were tend to be overestimated in comparison with the direct shear strains. By numerical analyses, it is found that this overesmistimation is due to strain concentration on corners and deformation of flanges of the specimens. Shear stress of the specimen is assessed properly by the transmitted wave. These results are compared with the constitutive relation which is obtained from the stress bar experiments.