基于频率改变的结构损伤诊断方法

结构单元的损伤将导致损伤单元的单元刚度矩阵以及结构的总体刚度矩阵发生变化,通过损伤前后自振频率的改变,可对损伤单元刚度矩阵的损伤系数进行反演。本文发展了一种结构损伤定位和标定的两步方法,首先通过反演初步确定结构损伤的位置,然后将损伤单元(三维梁元)的刚度矩阵分解为拉压刚度矩阵和弯曲刚度矩阵,并分别对其损伤系数进行求解,从而确定截面积、截面惯性矩等单元截面参数的损伤情况。数值实验表明,该方法可对结构的损伤进行定位和标定。

Damage diagnosis of structures based on changes in frequency

The structural damage will cause the perturbation of the stiffness matrix and natural frequency.A two-step damage detection method of structures based on the changes of frequency is presented.First,the location of damage is estimated.Then,the stiffness matrix of the suspicious damaged elements is decomposed to the compressing stiffness matrix and the bending stiffness matrix,the damage ratios of them are calculated respectively.The damage ratio of the area and moment of inertia in the section of the damaged element can be quantified by this method.Numerical results show that the method can localize and quantify the damage in the structures.