平板穿透裂纹尖端应力强度因子计算方法研究

摘要

针对应力强度因子的求解问题,提出了基于平板穿透裂纹的最大张口位移计算裂纹尖端应力强度因子的新方法.首先根据Westergaard应力函数推导出具有中心穿透裂纹的无限大平板模型受两向均匀拉伸载荷时,裂纹最大张口位移与裂纹尖端应力强度因子之间的数学关系,然后利用有限元模拟计算研究了该数学关系针对含穿透裂纹的有限尺寸平板模型的适用性,包括有限板宽的边界效应、不同的载荷形式对应力强度因子求解的影响,并给出了针对实际力学模型计算裂纹尖端应力强度因子的修正方法.该研究成果为船舶与海洋结构物中含裂纹损伤局部结构的裂纹强度检测与评估提供了一条新的思路.%In order to find the solution for the stress intensity factor (SIF), a method to calculate the SIF at the tip of crack of a finite plate with a central through-crack based on the maximum crack opening displacement was proposed. Firstly, based on the Westergaard stress function, for a central through-crack in an infinite plate under two uniform tensile loads, the mathematical function relationship between the normal maximum crack opening displacement and SIF was deduced. Secondly, the finite element method was employed, and its influence on the mathematical relationship was studied by changing plate size and load forms. Finally, a modified method was given for practical calculation of SIF at the tip of crack by mechanical model. According to the research, a new idea was proposed to detect the SIF of a through-crack in a finite plate in ship and ocean engineering structures.