STRESS-STRAIN RELATION EVALUATION METHOD AND SPRINGBACK AMOUNT PREDICTION METHOD

摘要

PROBLEM TO BE SOLVED: To achieve high-accuracy calculation of stress-strain relation of an elastic-plastic material.SOLUTION: A stress-strain relation evaluation method in the invention includes steps of: using an experimental value for a stress-strain relation of an elastic-plastic material to calculate a material constant for the elastic-plastic material included in an elasto-plastic constitutive equation; using the calculated material constant to calculate a factor C that defines convergence speed of kinematic hardening of a yield surface; and calculating the stress-strain relation of the elastic-plastic material by substituting the calculated material constant and factor C into the elasto-plastic constitutive equation. This enables high-accuracy calculation of stress-strain relation of the elastic-plastic material because the factor C that defines the convergence speed of kinematic hardening of the yield surface changes according to a stress state.