基于D-P准则的三维弹塑性有限元增量计算的有效算法  

A practical 3D elasto-plastic incremental method in FEM based on D-P yield criteria

作　　者：杨强[1] 陈新[1] 周维垣[1] 

机构地区：[1]清华大学水利系,北京100084

出　　处：《岩土工程学报》2002年第1期16-20,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金资助项目 (598790 0 5) ;清华大学基础研究基金资助项目

摘　　要：针对岩土材料常用的D -P准则 ,提出了一种新的增量分析方法 ,不用形成弹塑性增量矩阵 ,直接导出了符合正交流动法则的转移应力的解析解。该方法无论是对小步长还是大步长加载均有良好的收敛性。当采用精细的步长划分时 ,它就是严格意义上的理想弹塑性增量计算。在大步长情况下 ,在收敛域内最大载荷低于结构真实的极限承载力 ;对应的应力场是一个静力容许应力场 ;同时由于正交流动法则在平均意义下得到满足 ,收敛域内最大载荷接近结构真实的极限承载力。按此法所得结果接近真解且偏于安全。将整个计算模型装入三维非线性有限元程序TFINE中 ,对某拱坝进行了超载分析。In this paper, focused on popularly used D-P yield criteria in geomaterials, a new incremental method in which the stresses to be transferred according to normal flow rule are directly derived without forming elasto plastic increment matrix, was proposed. This method converges for either small load steps or large load steps. When very small load steps are used, the method is equivalent to standard elasto plastic incremental method. When large load steps are used, the maximum load applied is lower than limit load in structure, the calculated stress field is an static admissible one. As normal flow rule is satisfied in average, the maximum load is close to limit load. The soltion calculated by the method is on the safe side and close to real solution. The method was embedded into a 3D nonlinear FEM software named TFINE,and overloading analysis was performed on an arch dam.

关 键 词：转移应力 极限载荷 岩土材料 三维弹塑性 有限元 

分 类 号：TU452[建筑科学—岩土工程]