广义协调平板型三角形壳元

本文构造了一种具有三个角点十八个自由度的平板三角形壳元GST18。其拉伸与弯曲部分分别由含旋转自由度的三角形膜元和薄板弯曲三角形元组成。广义协调方法的采用,使得该单元的收敛性得到保证。在结点上引入了平面内旋转自由度,从根本上克服了单元共面刚度矩阵出现奇异这一困难。对平面膜元采用了缩减积分方案,使该单元不会产生薄膜闭锁现象。数值算例表明,本文提出的GST18薄壳元是计算精度优于同类单元的可靠、实用的单元。

GENERALIZED CONFORMING TRIANGULAR FLAT SHELL ELEMENT

A triangular flat shell element GST18 with three nodes and eighteen degrees of freedom is constructed. The membrane and bending parts of the shell eloment are the generalized triangular membrane element with drilling freedoms GT9 and the generalized conforming plate bending element GPL-T9, respectively. By using the generalized conforming method the convergence of the element is guaranteed. By introducing the drilling freedoms the difficulty that the stiffness matrix is singular when the neighbouring elements around a common node are coplanar is overcome. The results of numerical tests demonstrate that the present element exhibits excellent performance.