中主应力对土体本构关系的影响

本文根据常规三轴试验和平面应变试验结果,对以常规三轴试验为基础的土体本构模型在平面变形问题中的适用性进行了研究.文中用双曲线模型和双屈服面弹塑性模型对两种试样的变形进行了计算比较.结果表明,两种模型用于平面问题都有误差,主要是由于两模型中所含破坏准则没有很好反映中主应力影响所致;中主应力主要通过对破坏准则的影响来影响本构关系.改进破坏准则,变形计算可得到很大改善.

Effect of Middle Principal Stress on Constitutive Relationship

The suitability of the constitutive models, which are based on the triaxial test results, to plane strain conditions is studied in this paper. Both the triaxial test and plane strain test are performed. The hyperbolic model and elliptic-parabolic two-yield-surface model are used to compute the deformation of the samples. The results show that there are some deviations in plane strain computation for both models. This is because the failure criterion implied in the models does not reflect the effect of middle principal stress. After revising the failure criterion, the deformation computation improved, since the middle principal stress influences the constitutive law mainly through failure criterion.