Hole Expansion Forming Analysis of Mild Steel Sheet Using a Material Model based on Crystal Plasticity

摘要

The effect of the calibration methods for determining the material parameters of a yield function on the predictive accuracy of the finite element analysis of a hole expansion forming for a cold rolled mild steel sheet is investigated. Biaxial tensile tests using cruciform specimens and multiaxial tension-expansion tube forming tests are conducted to calibrate the material parameters of the Yld2000-2d yield function. In addition, numerical uniaxial and biaxial tensile tests using the ALAMEL crystal plasticity model are performed to determine the parameters of the Yld2000-2d yield function. The thickness strain distribution of the specimens subjected to hole expansion forming is precisely measured and compared with those calculated using the material models calibrated using the experimental data and the numerical crystal plasticity biaxial tensile test data. The forming simulation results are consistent with the experimental observations.