扩展有限元裂尖场精度研究  

Accuracy study of crack tip field in extended finite element method

作　　者：宋娜[1] 周储伟[1] 

机构地区：[1]南京航空航天大学飞行器结构力学与控制教育部重点实验室,结构与强度研究所,南京210016

出　　处：《计算力学学报》2009年第4期544-547,共4页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(10472045,10772078);航空科学基金(05B52010)资助项目

摘　　要：论述了扩展有限元方法和基本原理,研究了单元类型(四边形单元和三角形单元、线性单元和二次单元)、网格密度、J积分区域半径等因素对裂尖局部应力场(应力强度因子)计算精度的影响。研究发现,上述因素对裂尖应力强度因子计算的收敛速度与稳定性影响不大,证实了XFEM可以用较少的节点获得较高的裂尖场精度,并提出了通过固定裂尖附加区半径可以进一步改善XFEM的收敛速度。A brief description of extended finite element method was offered firstly. Then effects, such as element type （quadra of J-integral region, on The study revealed that ngle or triangle element, linear of quadratic element）, mesh refinement, radius the accuracy of crack tip stress field （stress intensity factor） were investigated. all these do not significantly affect the convergence rate and stability of stress intensity fact tip can be method, in ors calculated by XFEM. This can lead conclusion that accurate local stress in front of crack ob W ined by XFEM with relatively coarse mesh compared with ordinary FEM. Finally, a ch a given domain size is enriched around the crack tip, was suggested in order to improve the accuracy of crack tip fields and convergence rate further more.

关 键 词：扩展有限元方法 裂纹 有限元逼近场 应力强度因子 收敛率 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]