MULTIAXIAL STRESS TESTS FOR METAL SHEETS AND TUBES FOR ACCURATE MATERIAL MODELING AND FORMING SIMULATIONS

Abstract

This paper is a review of the mechanical testing methods developed by the author's research group: multiaxial stress test methods using a cruciform test piece and a tubular test piece. The former is useful for small strain ranges under several percent while the latter is useful for larger strain ranges (from yielding to fracture). These test methods are useful to determine appropriate materials model for performing accurate metal forming simulations. Special attention is given to the measurement and modeling of the anisotropic plastic deformation behavior of sheet metals commonly used in industry and to the validation of the material models based on phenomenological yield functions for large plastic strain ranges. The effects of material models used in metal forming simulations on the improvement of the predictive accuracy for forming defects are also discussed.