Yield stress after double strain-path change

Two different types of complex loading paths, with three strain paths (rolling-rolling-tension), were carried on a polycrystalline copper sheet. The first and second paths in rolling were performed perpendicular to each other. Depending on the case, the last strain path in tension was considered to be parallel to the first or second rolling path. The effect of double strain path change on the subsequent reloading yield stress is studied in this work. The results show that the behavior after prestraining depends mainly on the orientation relationship between the previous (rolling-rolling) and the subsequent (tension) paths and less on the order in which they have been performed. The mechanical behavior in reloading is discussed on the basis of a statistical study of the slip systems that remain active after path change.