Application of gradient plastic theory based on FEPG platform
DU Xiu-li1, HOU Shi-wei1, LU De-chun1, LIANG Guo-ping2, AN Chao3
1. Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing 100124, China; 2. Beijing FEGEN Software Co., Ltd., Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100098, China; 3. School of Earth and Space Science, Peking University , Beijing 100871, China
Abstract：Based on the FEPG platform, the finite element program using gradient plastic theory is developed to solve mesh dependence after strain softening. A algorithm with damp factor is proposed, which can solve the equation of displacement and yield surface simultaneously. The algorithm can not only get displacement and plastic multiplier together, but also avoid the stress haul back calculation in stress return algorithm widely used in finite element solution procedures. The softening modulus and the internal character length are introduced into D-P yield function, and the constitutive model can consider strain softening and gradient effect. The damp Newton algorithm is used to calculate softening problems. The results of a case study show that the algorithm with damp factor can be used to solve softening problems, the gradient plastic theory described by finite element weak form has no requirement of continuity, and appropriate outcome can be obtained by the first-order element, thus the mesh dependence of simulation is basically solved.
杜修力, 侯世伟, 路德春, 梁国平, 安超. 梯度塑性理论的计算方法与应用[J]. 岩土工程学报, 2012, 34(6): 1094-1101.
DU Xiu-li, HOU Shi-wei, LU De-chun, LIANG Guo-ping, AN Chao. Application of gradient plastic theory based on FEPG platform. Chinese J. Geot. Eng., 2012, 34(6): 1094-1101.
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