【摘要】 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，建立起了各种特征线场之间的定量关系，形成了一个系统的理论，现有的特征线场均为文中统一理论的特例．该统一特征线场理论还可以构造出一系列新的特征线场．用文中的理论进行分析能更好地与实验结果相吻合，并且可以方便地用于解决众多工程实际问题．更多还原

【Abstract】 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.更多还原