Numerical and experimental study of strain distribution of trip steel sheet using hydraulic bulge test

This paper presents a numerical and experimental study of strain distribution in a spherical cup drawn from TRIP steel RAK 40/70 by hydraulic bulge test. The strain distribution was measured based on the data obtained by coordinate measuring machine (CMM) to identify the wall thickness and plastic anisotropy through measuring the circularity. Numerical modelling of hydraulic bulge test was performed in two types of finite element code - explicit as well as implicit. Hill's family plasticity models with a combination of two types of the hardening curves were used in the simulation model of the bulging process. The FE analysis was compared with the experimental study. The results indicate that the model is applicable to describe the wall thickness, strain distribution and bulged profile.