Influence of loading sequence on the Bauschinger curve.

Abstract

In case of some kinds of material, distinct difference between pre-tensed and pre-compressed Bauschinger's stress-strain curves occurs. Experiments of copper test pieces were conducted in pre-strain region to about 30% in this paper. From the test data, the ratio of two stress values in the narrowest point between simple stress-strain curve in pre-strain direction and reversely loaded stress-strain curve which is shifted by pre-strain value and shown in pre-strain direction is approximately 0.94, not depending on kinds of pre-strain and pre-strain value. Therefore the above said difference of Bauschinger's curve is derived from difference between simple tensile and compressive stress-strain curves in some kinds of material. And also this phenomenon can be explained by observation of slip bands.