基于离散元法与有限元法耦合模型的网壳结构倒塌过程分析

发布时间：2018-03-16 16:39

本文选题：离散元法　切入点：显式有限元　出处：《建筑结构学报》2017年01期 　论文类型：期刊论文

【摘要】：针对有限元法(FEM)处理不连续位移场所存在的难以收敛、网格需重新划分、裂尖奇异场网格密度大等问题,结合离散元法(DEM)的优点,提出了一种DEM/FEM耦合计算模型。基于罚函数法,通过建立虚功方程及变分原理,得到了界面耦合力的计算公式,给出了耦合模型计算流程并自主开发了相关计算程序,通过算例验证了该耦合计算模型的正确性。并将该耦合模型用于单层球面网壳结构受冲击荷载作用下的倒塌过程仿真,比较了纯FEM、纯DEM及DEM/FEM耦合三种不同计算模型的数值结果与计算效率。计算结果表明:DEM/FEM耦合模型应用于网壳结构倒塌数值模拟时,与纯DEM模型相比,可减少计算规模从而节省机时,计算效率高;在处理强非线性问题时,纯FEM存在不收敛现象而耦合模型则能顺利完成计算分析,更具算法稳定性优势。
[Abstract]:In view of the problems such as the difficulty of convergence in the discontinuous displacement site treated by the finite element method (FEM), the need to redivide the mesh and the large density of the grid in the singular field of the crack tip, a DEM/FEM coupled computing model is proposed based on the penalty function method, combined with the advantages of the discrete element method (DEM). By establishing the virtual work equation and variational principle, the calculation formula of the interface coupling force is obtained, and the calculation flow of the coupling model is given, and the related calculation program is developed independently. An example is given to verify the correctness of the coupled model, and the coupling model is used to simulate the collapse process of single-layer spherical latticed shell under impact loading. The numerical results and computational efficiency of three different computational models of pure FEM, pure DEM and DEM/FEM coupling are compared. The results show that the ratio DEM / FEM coupling model is applied to the numerical simulation of collapse of latticed shell structures, which is compared with the pure DEM model. It can reduce the calculation scale and save the computer time, and when dealing with the strong nonlinear problems, the pure FEM has the phenomenon of non-convergence and the coupling model can successfully complete the calculation and analysis, which has the advantage of the stability of the algorithm.
【作者单位】：东南大学混凝土及预应力混凝土结构教育部重点实验室;
【基金】：国家杰出青年科学基金项目(51125031)
【分类号】：TU399;TU312.3

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