缺口对悬臂板裂纹扩展和固有频率演变的仿真分析

Simulation study of notch on crack propagation and naturalfrequency evolution of cantilever plate

本文选取不同初始缺口长度的悬臂板为研究对象,对其裂纹扩展和固有频率演变进行数值研究。首先,建立一种基于ABAQUS-FRANC 3D的联合仿真分析方法,其中ABAQUS用于结构的有限元分析,FRANC 3D基于ABAQUS数值结果进行裂纹扩展仿真。其次,评估了初始缺口长度与裂纹扩展行为和固有频率演变的关系。研究表明,悬臂板初始缺口长度越大,固有频率随着裂纹扩展长度的增加衰减速度越快,固有频率变化率随着裂纹扩展长度的增加可分为3个阶段:缓慢增加、匀速增加和快速增加阶段;固有频率变化率与应力强度因子呈对数线性关系,与裂纹扩展速率曲线相似。最后,评估了缺口应力集中系数对悬臂板疲劳寿命的影响,影响规律符合指数函数模型。

This paper focuses on the numerical investigation of crack propagation and natural frequency evolution of cantilever plates with different initial notch lengths.First,a combined simulation analysis method based on ABAQUS-FRANC 3D is developed.ABAQUS is employed for finite element analysis of the structure,while FRANC 3D is used to conduct crack propagation simulation based on numerical results from ABAQUS.Second,the relationship between initial notch length and crack propagation behavior as well as the evolution of natural frequency is evaluated.Our results indicate for cantilever plates,a larger initial notch length leads to a faster attenuation of natural frequency with the increase of crack propagation length.The rate of change of natural frequency with respect to crack propagation length is divided into three stages:slow increase,constant increase,and rapid increase.The rate of natural frequency change exhibits a logarithmic linear relationship with stress intensity factor,similar to the crack propagation rate curve.Finally,the impact of stress concentration factor induced by notches on the fatigue life of cantilever plates is assessed,which shows a relationship with fatigue life consistent with an exponential function model.