双材料界面裂纹的加料有限元方法

为解决求解双材料界面裂纹应力强度因子等断裂参量的困难，在常规单元位移模式中引入界面裂纹尖端位移场，构建加料界面裂纹单元和过渡单元的位移模式，推出了加料有限元方程。采用不同的加料单元和过渡单元配置方案，建立了方形板中心界面裂纹和矩形板单边斜界面裂纹的加料有限元模型，求解有限元方程直接得到应力强度因子，与解析解的结果对比，表明该方法具有较高的精度，可方便地推广应用于界面裂纹的计算分析中。
The enriched finite element method is used to solve the stress intensity factors for two bonded dissimilar materials containing a crack along the bond. By appending the displacement expressions for an interface crack to the common element, the enriched and transition element displacement model are obtained; the enriched finite element equation is derived. Two enrichment schemes are introduced to establish the finite element models for square plate center interface crack and rectangular plate unilateral oblique interface crack. The stress intensity factors are calculated directly from the finite element equation. The results, which are obtained by compared with analytical results, demonstrate that the enriched finite element method is a convenient and high precision calculation method for interface crack problems.