Experimental and finite-element simulation results for a plane-strain punch-test using isotropic and anisotropic materials

Strength constitutive relationships that account for yield surface expansion (i.e., strain-rate hardening, strain hardening and thermal softening) and shape changes (anisotropy) are important for the simulation of metal cutting with Finite Element (FE) techniques. The behavior of 70:30 brass and pure Zn have been examined in the context of the symmetric plane-strain punch test shown in sectional view. This test can be viewed as a precursor orthogonal machining (metal-cutting) problem with a rake (alpha) and clearance angles of 0 degrees. Punch test simulations using an explicit continuum mechanics code are presented and compared to experimental profile and hardness data in the spirit of the work of Weinmann and Turkovich. The rate-dependent elastoplastic constitutive behavior, experimentally measured for these materials, is treated using von Mises and quadratic yield functions (f=0) for brass and Zn, respectively, in conjunction with the Mechanical Threshold Stress (MTS) flow stress (sigma) model. In this paper, we first describe the punch test, present the experimental data, review briefly the constitutive modeling used in the FE simulations, and then compare the simulation results and the experimental data.