修正的内部基扩充无网格法求解多裂纹应力强度因子

修正的内部基扩充无网格Galerkin法求解了多裂纹应力强度因子。采用特征距离对内部基扩充无网格法进行修正,应用变分原理推导了系统离散方程,给出相互作用能量积分计算混合型模式下的应力强度因子的公式。求解3个平面应力条件下的多裂纹问题,并与其他数值方法的计算结果进行比较。数值算例表明：修正的内部基扩充无网格Galerkin法可以方便、有效地求解多裂纹问题,在不增加附加节点和自由度的情况下便可以得到较高精度的计算结果。

SOLVING STRESS INTENSITY FACTORS OF MULTIPLE CRACKS BY USING A MODIFIED INTRINSIC BASIS ENRICHED MESHLESS METHOD

Stress intensity factors of multiple cracks were calculated by using a modified intrinsic basis enriched element-free Galerkin method. The modification was based on the concept of characteristic distance and incorporated the interaction of neighboring cracks. Linear discrete system equations were obtained by applying the variational principle. The mixed-mode stress intensity factors were solved by the interaction integral method. Three examples were tested under plane stress conditions. The results from the modified intrinsic basis enriched meshless method were compared with those obtained by other numerical methods. It is found that the proposed method deals with multiple crack problems easily and effectively, and achieves high levels of accuracy without increasing the number of nodes or degrees of freedom.