裂纹损伤对典型船体结构振动频率的影响规律研究

为研究裂纹损伤对典型船体结构振动特性的影响,选择加筋板作为典型船体结构,选择穿透性裂纹作为典型损伤形式。首先利用数值仿真和模型试验对带有裂纹的结构模型固有频率计算方法进行了研究,在此基础上针对边裂纹和中间裂纹2种形式进行了大量的仿真计算,得到模型各阶固有频率、频率变化率随裂纹位置和长度变化的规律。研究结果表明,结构各阶固有频率以及频率变化率对裂纹较为敏感,可以作为裂纹识别的特征参数。同时,试验和仿真计算结果数据也可以为裂纹损伤识别研究提供训练样本和验证样本。

Influence of crack damage on vibration frequency of typical hull structures

In order to study the vibration characteristics of typical hull structures under crack damage,the stiffened plates and penetrating cracks were selected as research objects.Firstly,numerical simulation and model test were used to study the calculation method of natural frequency and frequency change rate of structural models with cracks.On this basis,a large number of numerical simulations are carried out for the two forms of edge crack and center crack.The regularity of the natural frequency and the rate of change of frequencies with the crack location and length was obtained.The results show that the natural frequencies and the frequency change rate were sensitive to cracks and could be used as characteristic parameters for crack identification.At the same time,the experimental and simulation results could also provide training samples and validation samples for the research of crack damage identification algorithm.