Finite-Element Simulation of Deformation and Breakage in Sheet Metal Forming : 2nd Report, An Elastic-Plastic Analysis of Square-Cup Drawing Process

Abstract

The square-cup deep drawing process is numerically simulated by elastic-plastic FEM. J 2-flow theory (J2F), J 2-Goth's corner theory (J2G) and the biquadratic yield function for anisotropy, which were previously proposed by one of the authors, are used as constitutive equations. Friction coefficients on dies are measured using a model test, and the actual pressure distribution on the blank-holder is taken into account in the calculation. Breakage initiation is numerically evaluated by the authors' method, in which the onset of localized necking is adopted as the breakage condition, using the J2G constitutive equation and the biquadratic yield function. Numerical results such as distribution of displacement and strain along the die surface, the punch load, the breakage location, and the punch travel at the onset of breakage are in good agreement with the experimental results.