On Simulation of Bend/Reverse Bend of Sheet Metals

Abstract Bend/reverse bend tests are performed with a three-point bend test apparatus on two types of sheet metals, mild steel and high strength steel. The bend/reverse bend process tends to a steady cycle upon applying repeated cycles of displacements. Strain hardening and Bauschinger effects for both materials are detected. Three different hardening laws are used to simulate the bend process numerically. Isotropic hardening law overestimates the hardening component and by missing the Bauschinger effect and the plastic shakedown. Kinematic hardening rule underestimates the hardening component and exaggerates the Bauschinger effect. The combination of isotropic and nonlinear kinematic hardening predicts accurately both the Bauschinger effect and the plastic shakedown. The hardening parameters in the combined model are identified inversely by using micro genetic algorithm.