Saeed Hasan, Vancoillie Robin, Mehri Sofiani Farid, De Waele Wim
Soete Laboratory, Department of Electromechanical, Systems and Metal Engineering (EMSME), Faculty of Engineering and Architecture, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium.
Materials (Basel). 2024 Sep 28;17(19):4777. doi: 10.3390/ma17194777.
In linear elastic fracture mechanics, the stress intensity factor describes the magnitude of the stress singularity near a crack tip caused by remote stress and is related to the rate of fatigue crack growth. The literature lacks SIF solutions for cracks emanating from a three-dimensional semi-ellipsoidal pit. This study undertakes a comprehensive parametric investigation of the Mode I stress intensity factor (KI) concerning cracks originating from a semi-ellipsoidal pit in a plate. This work utilizes finite element analysis, controlled by Python scripts, to conduct an extensive study on the effect of various pit dimensions and crack lengths on KI. Two cracks in the shape of a circular arc are introduced at the pit mouth perpendicular to the loading direction. The KI values are calculated using the displacement extrapolation method. The effect of normalized geometric parameters pit-depth-to-pit-width (a/2c), pit-depth-to-plate-thickness (a/t), and crack-radius-to-pit-depth (R/a) are investigated. The crack-radius-to-pit-depth (R/a) is found to be the dominating parameter based on correlation analysis. The data obtained from 216 FEA simulations are incorporated into a predictive model using a k-dimensional (k-d) tree and k-Nearest Neighbour (k-NN) algorithm.
在线弹性断裂力学中，应力强度因子描述了由远场应力引起的裂纹尖端附近应力奇异性的大小，并且与疲劳裂纹扩展速率相关。文献中缺乏关于从三维半椭圆形凹坑萌生的裂纹的应力强度因子解。本研究对平板中源自半椭圆形凹坑的裂纹的Ⅰ型应力强度因子（KI）进行了全面的参数研究。这项工作利用由Python脚本控制的有限元分析，对各种凹坑尺寸和裂纹长度对KI的影响进行了广泛研究。在垂直于加载方向的凹坑口处引入两条圆弧形裂纹。使用位移外推法计算KI值。研究了归一化几何参数凹坑深度与凹坑宽度之比（a/2c）、凹坑深度与板厚之比（a/t）以及裂纹半径与凹坑深度之比（R/a）的影响。基于相关性分析，发现裂纹半径与凹坑深度之比（R/a）是主导参数。使用k维（k-d）树和k近邻（k-NN）算法将从216次有限元模拟获得的数据纳入预测模型。
