结构损伤识别的数值模拟

为了找到一个对小损伤较敏感的参数,在结构自由振动微分方程基础上,结合损伤结构的测试数据(用有限元模型的计算结果来模拟),得到残余向量,利用广义逆和矩阵投影定理,导出了一个具有很好识别效果的参数:残余向量投影范数.从中很容易确定出损伤单元,进而计算出这个损伤单元的损伤因子即损伤程度.通过算例分析,发现该参数对结构中损伤非常敏感,能识别出结构中的微小损伤,而且不受损伤位置的约束,仅需要结构的前几阶模态就能达到很好的效果.

Numerical simulation of the structural damage identification

In order to find out parameters that have high precision of damage identification,based on differential equation of free vibration,in combination with the test data(simulated by the computational results of finite element model) from damaged structure,the residual vector is found.Then with the use of general inverse and matrix projection theorem,a new parameter with good identification effect is deduced,which is called projection modulus of residual vector,and with which the damaged element is easily identified from other elements.And then,the damage factor of the damaged element is computed.Based on another computational example,this method is considered very sensitive to the damage in structure.It can identify the minuteness damage in structure and get good effect with first few modes.