正交八面体应力空间的强度理论综述

OVERVIEW ON STRENGTH THEORY OF ORTHOGONAL OCTAHEDRON STRESS SPACE

正交八面体和等倾八面体是广义八面体理论体系中的两个重要的特征单元体,由此产生的正交八面体理论、以及弹塑性理论中的等倾八面体理论,都是广义八面体理论体系中的重要组成部分;正交八面体理论则是基于Mohr-Coulom理论、弹塑性理论和双剪理论所提出的。由于正交八面体的对称性和任意一个面与其中一个直角坐标轴相平行的特点,以及与应力和应变Lode参数、静水应力与中间主应力、体积应变与中间主应变密切相关等特点,因此具有丰富内涵;并据此可建立多轴特征强度参数方程和任意加载方式下的多轴极限强度模型等新的理论模型,以及根据应力—应变关系可将一些空间问题转换为平面问题等。

Orthogonal octahedron and isoclinal octahedron are two important characteristic element bodies, which are bases of generalized octahedron theory proposed and established by YANG Jian-hui （2007）, and orthogonal octahedron theory（YANG Jian-hui, 2007）, based on Mohr-Coulom theory, elastoplasticity theory and twin shear theory, and isoclinal octahedron theory applied to elastoplasticity theory, based on the two element bodies each other, are important parts of it too. Because of the symmetry and that any one diagonal section of orthogonal octahedron element body is parallel to a cartesian axis of coordinates in space, relations with orthogonal octahedron element body among stress-and strain-lode parameters, the hydrostatic stress, mean principal stress, the volumetric strain, mean principal strain, etc, so orthogonal octahedron theory has plenty inherent meanings. Thus new theory models, such as equations of multiaxial characteristic strength parameters and muhiaxial ultimate strength models under proportional or unproportional loading, etc, could be established, as well as the space problems could be transformed into the plane problems, and so on.