基于非协调广义混合元的含孔平板应力分析
2020-08-07姚玉卿光辉王绍波
姚玉卿 光辉 王绍波



摘 要:首先,根据广义HR变分原理建立了用于分析二维平面问题的非协调广义混合元。然后,应用该混合元对中心含孔平板的应力及应力集中系数等问题进行了详细的分析,并与二维的非协调位移元的结果进行了比较。在有限元模型相同的情况下,非协调广义混合元的结果精度明显优于常规的非协调位移元。另一方面,为了回避混合元法要求计算机内存空间较大的问题,提出了结构的局部区域非协调广义混合元方法。数值实例表明,局部区域非协调广义混合元方法是可靠的。
关键词:有限元方法;广义混合元;非协调广义混合元;含孔平板;应力集中系数
中图分类号:V257;O343.4文献标识码:A
Stress Analysis of Plate witha hole Based
on Incompatible Generalized Mixed Element
Yao Yuzhe Qing Guanghui* Wang Shaobo
College of Aeronautical Engineering,CAUC Tianjin 300300
Abstract:Firstly,based on the generalized HR variational principle,a nonconforming generalized mixed element is established for the analysis of twodimensional problems.Then,the mixed element is applied to analyze the stress and stress concentration factor of the central plate with holes in detail,and the results are compared with those of the twodimensional incompatible displacement element.In the case of the same finite element model,the result accuracy of the incompatible generalized mixed element is obviously better than that of the conventional incompatible displacement element.On the other hand,in order to avoid the problem that the mixed element method requires large memory space,a local incompatible generalized mixed element method is proposed.The numerical examples show that the local incompatible generalized mixed element method is reliable.
Key words:finite Element method;generalized mixed element;nonconforming generalized mixed element;plate with a hole;stress concentration factor
为了满足装配或服役过程中的维护修理等方面的要求,在现代工程结构,尤其是飞机器这类复杂的工程结构,常常要求在结构的零部件上打孔或开口。这些孔或开口的出现势必导致对结构寿命有着重要影响的应力集中问题。对于含有多个孔或复杂开口的零部件,人们通常采用试验或有限元数值方法分析其应力集中问题。在网格较稀疏的情况下,最常见的位移有限元法[1]的结果往往不是很理想。实质上,通常的位移有限元法求得的位移精度高,但是应力精度比位移精度差一个阶次,这是由于节点的应力结果是依据本构关系逐一单元计算的,因而造成连接多个单元的同一节点上出现了不同的应力结果,所以必须对节点应力进行恢复或磨平的操作。……
