The isogeometric boundary element method (IGABEM) is developed to simulate the crack propagation and the inclusion-crack interaction in 3D infinite isotropic medium. The influence of complex shape inclusions on the stress intensity factors (SIFs) along the crack front is studied from the aspects of shape, stiffness, size and position. The non-uniform rational B-spline (NURBS) basis functions can be used to accurately describe the geometric shapes of inclusions and cracks, and the displacement, traction, and discontinuous displacement fields also can be approximated by the same NURBS basis functions. During crack propagation, the normal and tangential vectors of the crack boundary can be uniquely solved. Three examples verify the accuracy and effectiveness of the proposed method. The results show that the SIFs can be calculated accurately even using the single point formula, and the crack propagation process is stable and the path is smooth.

开发了等几何边界元方法 (IGABEM) 来模拟 3D 无限各向同性介质中的裂纹扩展和夹杂物-裂纹相互作用。从形状、刚度、大小和位置等方面研究复杂形状夹杂物对裂纹前沿应力强度因子(SIFs)的影响。非均匀有理 B 样条 (NURBS) 基函数可用于准确描述夹杂物和裂纹的几何形状，位移、牵引力和不连续位移场也可以用相同的 NURBS 基函数近似。在裂纹扩展过程中，裂纹边界的法向和切向矢量可以唯一求解。三个例子验证了所提出方法的准确性和有效性。