Numerical study of influence of superimposed pressure on FLD

The effect of superimposed hydrostatic pressure on the initiation of localized necking is studied numerically. The Forming Limit Diagram (FLD) is constructed based on crystal plasticity theory in conjunction with the M-K approach. It is found that the superimposed pressure delays the initiation of necking for any strain path. The amount of the limit strain increment due to the hydrostatic pressure is path dependent with the increment in in-plane strain tension being larger than that in uniaxial tension and in equi-biaxial tension. (author)