适用于壳体h型自适应有限元分析的一组新单元

推导出一组适用于h型自适应分析的四边形蜕化壳元。对于大多数壳体结构，壳单元的刚度矩阵可分为薄膜、弯曲和剪切三部分。对薄膜部分本文采用杂交应力元方法进行设计,独立假设薄膜应力场以改善其精度；弯曲部分的刚度矩阵则依然由基于位移的应变来获得；而剪切部分则采用假设自然应变的方法来获得能克服薄壳下剪切自锁的新剪应变并用于计算此部...

A new family of elements for h-type adaptive analysis for shell problems

In this paper, a new family of degenerated shell elements being suitable for h-type adaptive analysis is presented. For most of shell structures, the stiffness matrix of the shell element can be split into membrane, bending and shear stiffness matrices. For the membrane part, the membrane stresses are independently assumed and the pertinent stiffness matrix is obtained by the hybrid element method to improve the accuracy of membrane stresses. For the bending part, displacement-based strain is kept intact and used to formulate the corresponding stiffness matrix. For the shear part, the assumed natural strain method is employed to construct the shear strains to obtain pertinent stiffness matrix and overcome shear locking for thin shell problems. Several numerical examples are presented. With the newly developed element family, more regular meshes are generated and the convergence rate is higher than those yielded by using other element families.