基体的真实应力理论

连续介质力学中，各向同性材料的力学理论已基本成熟，即，对任何一个各向同性材料的力学问题，人们几乎总能从现有理论中找到有效解决方案，但对各向异性材料暨复合材料而言，只有线弹性理论才基本成熟，复合材料的塑性变形、破坏和强度等问题，都还缺少成熟分析方法。根本原因是，现有理论只能得到纤维和基体中的均值应力，复合材料的塑性、破坏和强度分析，都必须基于基体的真实应力。本文对作者创建和发展的基体真实应力理论进行了综述介绍，并简要指出了真实应力理论在复合材料破坏和强度分析中所起的作用。

True stress theory of matrix in a composite

In mechanics of continuum media, the theories for isotropic materials have been well established. Namely, one is almost always able to find out an existing theory to resolve any mechanics problem of an isotropic material satisfactorily. In the contrast, only elastic theories for anisotropic or composite materials have been matured. The other mechanical property of the composite, such as a plastic deformation or failure and strength behavior, is essentially not well understandable through an available theory. The fundamental reason is that only the homogenized stresses in the fiber and matrix of a composite are obtainable by an existing theory. They must be converted into true values before the plastic behavior and, especially, the failure and strength property of the composite can be estimated. In this paper, the true stress theory of the matrix together with the formulae for calculating all of the matrix true stresses established by the author is summarized. The role of the matrix true stress theory in the analysis of composite plastic behavior and failure and strength property is highlighted.