Analysis of Anisotropic Plastic Properties of Perforated Sheet Metal Using Homogenization Method

Abstract

In this study, the anisotropic plastic properties of perforated sheet metal with regular staggered holes were analyzed by the homogenization method. A hexagonal unit cell with periodic boundary conditions was selected for the analysis. To validate the analysis results, comparisons were made with the experimental results obtained from a uniaxial tensile test. The analyzed stress-strain curves obtained from directional tensile tests match the corresponding experimental stress-strain curves. The in-plane variations of the analyzed r-values also agree qualitatively with the experimental results. In the biaxial tensile test, the macro yield surface was evaluated as an equal plastic work contour in the proportional stress path. Obtained results indicate differential (anisotropic) hardening and slight tension-compression asymmetry of the subsequent macro yield surface. In the case of the proportional loading path, the associated flow rule (AFR) for the initial and subsequent yield surfaces is applicable. However, regarding the non-proportional loading path, the AFR may not be applicable in certain cases because the distribution patterns of the strain rate around the holes depend on the history of local work hardening.