正交异性材料平面应力问题在无量纲应力屈服准则下的特征场

将正交异性材料看成理想塑性材料，在无量纲应力屈服准则及与之相关的流动法则下，利用特征场的一般方法，建立了平面应力问题的特征场，一阶拟线性方程组可能为双曲型，抛物型，椭圆形，在双曲型区域两族特征线互不正交，应力场的特征与速率线互相重合，当材料退化为各向同性材料时，推导的结果能退化为希尔解或素柯洛夫斯基解。

Characteristic Fields of Plane Stress Problem With Perfectly Plastic Orthotropic Materials by Dimensionless Stress Yield Criterion

The mechanical behavior of the orthotropic materials is regarded as perfectly plastic in order to simplifythe analysis. The characteristic fields of plastic plane stress problems are construeted. By following dimensionlessStress Yield Criterion and the associated plastic flow rule. The quasi-linear differential equations may be hyperbolic,parabolic and elliptic. Two fdmilies Of characteristic lines in the hyperbolic region are not orthogonal. The character-istic lines of velocity coincide with those of stress field. When the orthotroPic materials degenerate to isotropic ones,the solution presented in this paper can degenerate tO that presented by Hill R or by Sokolovskii V V.