Numerical simulation of ductile fracture behavior for aluminum alloy sheet under cyclic plastic deformation

A numerical analysis of mechanical behavior of aluminum alloy sheet under cyclic plastic deformation was investigated. Forming limit at fracture was derived from Cockcroft-Latham ductile damage criterion. The strain path of bending center of incremental roller hemming could be accepted as a kind of plane strain bending deformation process. Incremental rope roller hemming could be used to alleviate ductile fracture behavior by changing the stress state of the hemming-effected area. SEM observation on the fracture surface indicates that cyclic plastic deformation affects ductile fracture mechanism.