多孔体材料在镦粗变形过程中表面裂纹的有限元预测

将传统的镦粗试验方法用于多孔体材料的塑性变形过程．以多孔体材料的塑性理论为基础，采用体积可压缩的刚塑性有限元法模拟多孔体材料的塑性变形过程．同时以Ｌｅｅ－Ｋｕｈｎ通过实验获得的局部应变极限准则为破裂条件，获得了在不同摩擦因子、高径比和初始相对密度条件下鼓形部位出现破裂的极限工艺参数．将模拟６０１ＡＢ多孔体材料的结果与Ｌｅｅ－Ｋｕｈｎ实验结果进行了对照．

Prediction of Surface Crack during Cylindrical Upsetting of Porous Materials by FEM

The traditional upsetting experiment method is applied into the deformation of porous materials. Based on the plastic theory of porous metal materials, a compressible rigid plastic finite element method(FEM) is used to simulate the deformation process of a cylindrical upsetting of porous metal material. The critical process parameters are predicted in terms of the local compressive and tensile strain criterion obtained by Lee Kuhn's experiments at the different initial conditions which include friction factor ( m ), relative height ( H/D) and relative density ( R 0). The predicted results of the porous materials 601AB are compared with those of Lee Kuhn's experiments.