基于晶体学理论预测金属薄板屈服行为和成形极限

PREDICTION OF YIELD BEHAVIOR AND FORMING LIMIT OF SHEET METAL BASED ON POLYCRYSTALLINE PLASTICITY THEORY

应用 Ｔａｙｌｏｒ理论模拟了体心立方（ＢＣＣ）和面心立方（ＦＣＣ）金属在平面应力条件下的各向同性屈服行为。将计算结果与Ｂａｒｌａｔ－ｌｉａｎ提出的屈服函数进行了比较，从微观角度讨论了宏观屈服函数的相关参数，然后结合描述塑性失稳的改进 Ｍ．Ｋ理论，选择屈服函数的相关参数，预测了 Ａ－Ｋ Ｓｔｓｅｌ和 ２０３６－Ｔ４铝合金板的成形极限（Ｆ［Ｄ），通过与试验结果比较，确定了相关参数的最佳选择。

The isotropic yield behaviors of BCC and FCC metals under plane stress condition are simulated with the Taylor theory. The results are compared with a proposed yield fUnction(Barlat-Lian yield function)in culer to determine its parameter. Then the yield function with the correct parameter choice is incooprated with the M-K model to predict the forming limit of sheets, and to compare with a steel and an aluminum alloys, which gives good agreements with experiments.