OS0119 二軸引張を受けるAZ31板の成形性

抄録

Formability of AZ31 sheet under biaxial stretching modes is investigated. Forming limit strains of specimen are measured by using stretch forming experiment. RD-ND plane of fractured specimen was observed by an optical microscope and it is found that a visible local thinning was not created before fracture. Finite element simulations were conducted based on a crystal plasticity model, which incorporates only slip mechanism and twinning is excluded. The strain distribution simulated by finite element method reveals that the strains easily localize at several narrow portions in the specimen for the equi-biaxial stretching and plane stretching modes. On the other hand, the intensity of such localization is weakened when the specimen undergoes uniaxial tension. The nonuniformity of the deformation leads to the premature fracture of AZ31 for biaxial stretching modes.