A damage based mechanics model predicting forming limit of sheet metal under non-proportional loading

探讨了用损伤基力学模型研究应变路径对薄金属板塑性失稳的影响 ,这种力学模型考虑了材料损伤作用 .基于这种模型 ,在等效应变空间建立了考虑损伤的塑性失稳判据 ,并用以预估在比例或非比例加载下薄金属板成型极限曲线 (FLC) .借助这种理论模型和方法 ,预估薄金属板的理论成型极限曲线与Graf和Hosford的实验结果一致 .||The influence of strain path on plastic instability of sheet metal is investigated by the damage based mechanics model, which takes the effects of damage into account. Based on the model, a plastic instability criterion due to material damage has been established, in the equivalent strain space, in order to predict the forming limit curve (FLC) under the conditions of both the proportional and the non-proportional loading process. The FLC results of the present model are agreement with the experimental data by Graf and Hosford.