Cyclic hardening behavior of roller hemming in the case of aluminum alloy sheets

A method to investigate the cyclic hardening behavior of roller hemming in the case of aluminum alloy sheets is described in this approach. Roller hemming hardening behaviors are studied with numerical simulation. The minimum sets of uniaxial experiments are established for the determination of accurate constitutive parameters. A special specimen holder, together with modified uniaxial specimens with two side fins is used in uniaxial tension and compression tests to determine combined hardening parameters. The material parameters are verified by pre-hemming roll-in/out data. It is also demonstrated that the combined hardening parameters derived from the minimum set of uniaxial tests with the aid of special specimen holder and modified specimens are accurate and believable.