金属材料的平面应力非连续分叉

DISCONTINUOUS BIFURCATIONS OF METALLIC MATERIALS FOR PLANE STRESS

对已有弹塑性体非连续分叉结果进行了修正 ,使其更为合理。在此基础上 ,基于统一屈服准则 ,得出了金属材料非连续分叉的起始方位角以及相应的硬化模量的统一解析解 ,并且分析了不同程度的中间主应力对结果的影响。进而发现所得的结果与屈服准则的选取有关 ,揭示了在分叉研究中正确选取符合金属材料特性的强度准则的重要性。

Theory proposed before on the properties of discontinuous bifurcation in elastic plastic materials is improved.Based on the new result,the unified initial direction of discontinuous bifurcations and the corresponding maximal value of the hardening modulus of the metallic materials for plane stress are obtained in regard to the unified yield criterion proposed by Yu in 1991 and 1992.The unified solutions take account of the influence of the intermediate principal stress on the properties of bifurcations.On the other hand,the dependence of the result of the bifurcation analysis on the adopted yield criterion is found.