一种带有沙漏控制的新型EAS实体壳单元

A new stabilized enhanced assumed strain (EAS) solid-shell element

基于Hu-Washizu变分原理推导了一种带有沙漏控制的实体壳单元的显式有限元列式;采用面内单点积分方案,提高了计算效率;同时引入沙漏控制力,抑制了沙漏现象。基于缩减积分方案,采用B-bar法消除体积自锁,并通过添加七个改善拟应变参数解决了泊松自锁和剪切自锁。采用改善拟应变法消除剪切自锁,使得表达式简洁。利用这种显式实体壳单元模型对3个非线性变形的标准算例进行了计算,并与相关参考文献和有限元软件ABAQUS的计算结果进行了比较。结果表明:该实体壳单元具有较高的计算精度,可有效地解决板壳非线性大变形分析问题,具有很好的工程应用前景。

In this paper,a stabilized solid-shell element is developed in the framework of explicit finite element based on the Hu-Washizu variational principle.A reduced in-plane integration scheme is adopted to improve computational efficiency and a physical stabilization procedure is employed in order to avoid hourglass phenomenon.Furthermore,the B-bar approach is employed to avoid volumetric locking and a seven-parameter enhanced assumed strain method is used to eliminate the Poisson and transverse shear locking pathologies of the element.One of the novelties of this paper is the adopting of enhanced assumed method in resolving transverse shear locking,leading to a more straightforward expression.In order to validate the present method,three benchmark tests involving material and geometrical nonlinearities are calculated with the developed program.The results are in good agreement with those presented in the references and calculated by ABAQUS.