三维接触面单元弹塑性损伤数值模拟分析方法

Three-dimensional elastic-plastic damage numerical simulation and analysis method for contact elements

针对岩土工程中出现的非连续结构面、接触面等问题,建立一种新的模拟结构面或接触问题的三维非线性接触单元模型;针对接触面非线性变形以及损伤演化特性,提出一种可以考虑接触面损伤演化过程的弹塑性损伤数值模拟方法;针对接触面张开、闭合以及剪切滑移失效等变形特性,模拟接触面的黏结、滑移和开裂等非线性现象。针对某水电站地下厂房岩锚吊车梁围岩与混凝土接触问题进行数值分析。研究结果表明:采用接触面单元模拟混凝土结构与围岩的相互作用,吊车梁受力情况良好,应力、变形分布正常,基本规律与实际相符,在工程实践中是合理可行的。

In light of discontinuous joints and interfaces in geotechnical engineering, a new three-dimensional nonlinear contact element model for the simulation of joints and contact problems was presented. Based on the nonlinear deformation and damage evolution characteristics of contact elements, an elastic-plastic damage numerical simulation method which takes the damage evolution process into consideration was proposed. In view of the deformation characteristics of contact elements such as opening, closing and shearing slip damage, some nonlinear phenomena like bonding, slip and cracking were simulated. The contact problem between surrounding rocks and concrete crane beam of underground powerhouse was taken as an example. The results show that concrete crane beam is of better stress condition and normal deformation distribution with the contact element model, and the basic laws conform to the actual situation, which verifies the good rationality and accuracy of the present model in engineering practice.