混和双应变强度理论研究

Study on Strength T heory of Mixed Twin Strains

本文使用‘双因素假设’建立了一个预测材料破坏的强度理论。该强度理论认为引起材料破坏的主要因素是最大剪应变和第二主剪切面上的正应变。只要最大剪应变和第二主剪切面上的正应变之和达到材料的相应极限值 ,材料就破坏。在此理论中 ,引起破坏的因素包括了度量变形的两个基本变量 ,剪应变和正应变 ,故称为混和双应变强度理论。该强度理论既能反映第二主应力对强度的影响又能反映泊松比对强度的影响。与传统的强度理论和双剪强度理论比较表明 ,该强度理论具有更广泛的应用范围。

This paper sets up a strength theory of predicting failure of materials using double factor assumption'.According to this theory,maximum shearing strain and normal strain on the second principal shearing plane play the key role on failure of materials.Whenever the sum of the maximum shearing strain and normal strain on the second principal shearing plane reaches the ultimate value of materials,the failure occurs.This theory is called strength theory of mixed twin strains because two basic variables of measuring deformation,shearing strain and normal strain,are simultaneously involved in the criterion.The strength theory of mixed twin strains is the first one which responses effects of both second principal stress and poisson's ratio on the strength.Comparing the theory presented in this paper with traditional strength theory and twin strength theory,it was found that the mixed twin strain strength theory is suitable for wider stress staters.