Finite element analysis of the three-point bending of sheet metals

Cyclic three-point bending tests on two types of sheet metals, mild steel and high strength steel, are reported. The bending process tends to a steady cycle upon applying repeated cycles of displacements. Strain hardening and Bauschinger effects for both materials were detected. Three finite element models are presented to simulate the three-point bending numerically. Different hardening laws are used with the simplified non-contact finite element model. The isotropic hardening law over-estimates the hardening component by missing the Bauschinger effect and the plastic shakedown. The kinematic hardening rule under-estimates the hardening component and exaggerates the Bauschinger effect. The combination of isotropic and non-linear kinematic hardening predicts accurately both the Bauschinger effect and the plastic shakedown. The hardening parameters in the combined model are identified inversely by using a micro-genetic algorithm. Cyclic stress–strain curves are generated based on the identified material parameters.