Alshoaibi Abdulnaser M
Mechanical Engineering Department, Faculty of Engineering, Jazan University, P.O. Box 114, Jazan 45142, Saudi Arabia.
Materials (Basel). 2022 Apr 18;15(8):2937. doi: 10.3390/ma15082937.
Damage tolerant design relies on accurately predicting the growth rate and path of fatigue cracks under constant and variable amplitude loading. ANSYS Mechanical R19.2 was used to perform a numerical analysis of fatigue crack growth assuming a linear elastic and isotropic material subjected to constant amplitude loading. A novel feature termed Separating Morphing and Adaptive Remeshing Technology (SMART) was used in conjunction with the Unstructured Mesh Method (UMM) to accomplish this goal. For the modified compact tension specimen with a varied pre-crack location, the crack propagation path, stress intensity factors, and fatigue life cycles were predicted for various stress ratio values. The influence of stress ratio on fatigue life cycles and equivalent stress intensity factor was investigated for stress ratios ranging from 0 to 0.8. It was found that fatigue life and von Mises stress distribution are substantially influenced by the stress ratio. The von Mises stress decreased as the stress ratio increased, and the number of fatigue life cycles increased rapidly with the increasing stress ratio. Depending on the pre-crack position, the hole is the primary attraction for the propagation of fatigue cracks, and the crack may either curve its direction and grow towards it, or it might bypass the hole and propagate elsewhere. Experimental and numerical crack growth studies reported in the literature have validated the findings of this simulation in terms of crack propagation paths.
损伤容限设计依赖于精确预测在恒定和变幅载荷下疲劳裂纹的扩展速率和路径。使用ANSYS Mechanical R19.2对假设为线弹性各向同性材料且承受恒定幅载荷的疲劳裂纹扩展进行数值分析。一种名为分离变形与自适应网格重划分技术（SMART）的新特性与非结构化网格方法（UMM）结合使用以实现这一目标。对于具有不同预裂纹位置的改进紧凑拉伸试样，针对各种应力比数值预测了裂纹扩展路径、应力强度因子和疲劳寿命周期。研究了应力比在0至0.8范围内时对疲劳寿命周期和等效应力强度因子的影响。发现疲劳寿命和冯·米塞斯应力分布受应力比的显著影响。随着应力比增加，冯·米塞斯应力降低，并且疲劳寿命周期数随着应力比的增加而迅速增加。取决于预裂纹位置，孔是疲劳裂纹扩展的主要吸引点，裂纹可能会弯曲其方向并向其扩展，或者它可能绕过孔并在其他地方扩展。文献中报道的实验和数值裂纹扩展研究在裂纹扩展路径方面验证了该模拟的结果。
