Experimental investigation of an anisotropy in copper subjected to predeformation due to constant and monotonic loadings

Abstract

Experimental analysis of the plastic properties for both an aged pure copper and the same material subjected to various types of predeformation is presented. The analysis was made by studying; the position in stress space and by determination of dimensions of the yield surfaces. The initial yield surface has been determined using the probing technique of a single specimen and this surface was used as the starting point for comparative studies of yield surfaces of the prestrained material. The material predeformations of the same magnitude were induced either by a creep process at elevated temperature or by monotonic loading at ambient temperature. After required values of plastic prestrain were attained, yield surfaces were determined by the same method as for the non-prestrained material. The anisotropic yield condition was used to create a least squares fit of the experimental data.