Measurement of work hardening behavior of 5052 aluminum alloy sheet subjected to cross loadings

Stress–strain relationships of A5052-O subjected to various cross loading paths were experimentally observed. Cross-loading paths consist of the uniaxial tension in the rolling direction and the following simple shear applied along the orientation inclined at 0°, 45°, 90°, and 135° from the rolling direction. These cross-loading paths result in so-called orthogonal, quasi-monotonic, and quasi-reverse loadings. In the orthogonal loading, the reyield stress and the subsequent flow stress were higher than the flow stress in the monotonic simple shear, and the work hardening rate was decreased. The same type of the work hardening behavior was observed even for the quasi-reverse and quasi-monotonic loadings. Thus, cross effect occurred for a wide range of the change in the strain paths. Subsequently, the cross-loading paths were applied to a steel sheet (SPCE). For the steel sheet, the reyield stress was reduced in the quasi-reverse loading, and no cross effect was observed for the quasi-monotonic loading. From comparisons of the cross-hardening behaviors and R values of A5052-O and SPCE, it is revealed that the tension–shear type cross loading cannot mimic the reverse and monotonic loading paths, if the R value is small.