Abstract

The extended finite element (XFEM) has been applied to investigate fatigue crack growth in engineering components containing different types of material irregularities. The standard approximations of finite element method are enriched with additional functions by employing the partition of unity approach. In order to keep track of discontinuities in the domain, level set method is employed. Fatigue crack growth in presence of different material irregularities, such as elliptical, rectangular, hexagonal and octagonal discontinuities, has been the main focus of the study. The effect of geometry, position and material properties of these discontinuities on fatigue behavior of the cracked specimen has been addressed. The fatigue life of the cracked component has been estimated by the generalized Paris law. The mixed mode stress intensity factors have been evaluated by the domain-based interaction integral approach. Several numerical problems are solved by XFEM to study the fatigue crack growth behavior of cracked specimens containing different types of material irregularities.

摘要

扩展有限元 (XFEM) 已应用于研究包含不同类型材料不规则性的工程部件中的疲劳裂纹扩展。有限元法的标准近似通过采用单位分割法丰富了附加功能。为了跟踪域中的不连续性，采用水平集方法。存在不同材料不规则性（例如椭圆形、矩形、六角形和八角形不连续性）下的疲劳裂纹扩展一直是研究的主要焦点。已经解决了这些不连续性的几何形状、位置和材料特性对破裂试样疲劳行为的影响。裂纹部件的疲劳寿命已通过广义巴黎定律估算。混合模式应力强度因子已通过基于域的相互作用积分方法进行了评估。XFEM 解决了几个数值问题，以研究包含不同类型材料不规则性的裂纹试样的疲劳裂纹扩展行为。