塑性平面应力问题的统一特征线场理论

文中提出的塑性平面应力问题极限分析的统一特征线场理论，可以广泛适用于不同性质的各类材料，包括各类拉压强度相等的和不相等的各种金属类材料和非金属类材料。统一特征线场理论充分考虑了各种不同材料的中间主应力效应，建立起了各种特征场之间的定理关系，形成了一个系统的理论，有的特征线性均为文中统一理论的特例。

The Unified Characteristic Theory for Plastic Plane Stress Problems

Based on the unified strength theory proposed by the first author of this paper in 1991,a unified characteristic theory for solving plastic plane stress problems is established. This new characteristic theory takes account of the effect of the intermediate principal stress of various materials and reveals the relations among the different characteristic methods. Those characteristic methods on the basis of different strength theories, such as Tresca, Mises and Mohr Coulomb, are the special cases (Tresca and Mohr Coulomb) or linear approximation(Mises) of the proposed theory system. Besides, a series of new characteristic methods can be got from it. The unified characteristic theory can be adopted for most materials.It agrees with the experiments better than the previous characteristic methods.