平行双裂纹应力强度因子的计算方法

为了快速、方便地估算多裂纹尖端的应力强度因子，以承受均匀拉伸载荷的含平行双裂纹的有限平板模型为研究对象，提出了一种基于裂纹最大张口位移量确定平行双裂纹尖端应力强度因子的新方法.该方法以单裂纹问题中最大张口位移与应力强度因子间的函数关系为基础，考虑了平行双裂纹的垂向、纵向裂纹间距比和裂纹长度比的影响，拟合出纵向间距比为0时不同裂纹长度比下与垂向间距比相关的修正系数表达式，并进一步分析了裂纹纵向间距比对双裂纹尖端应力强度因子的影响，最终建立了平行双裂纹应力强度因子的简便方法.

A New Method to Calculate Stress Intensity Factor for Parallel Double Cracks

In order to obtain simply stress intensity factors (SIFs) of multi cracks, a new method was proposed to calculate SIFs of parallel double cracks based on maximum crack opening displacement (MCOD) for the double parallel cracked plate subject to uniform tension loads. On the basis of the obtained relationship between the SIFs and the MCOD in the single cracked model, the influences of crack spacing ratios (vertical and longitudinal) and crack lengths ratios were considered, and the function expressions between modified coefficients and vertical spacing ratios were fitted in the different crack lengths ratios conditions when longitudinal spacing ratios is zero. And then, the influences of crack longitudinal spacing ratios on SIFs of parallel double cracks were studied. Finally, an easy way to calculate the SIF of parallel double cracks was presented.