结构损伤识别中的广义残余力向量差法研究

Research on the Generalized Residual Force Vector Difference Method for Structural Damage Identification

采用矩阵摄动有限元方法,给出了结构损伤识别方程。为减小模型误差和测试误差对损伤识别结果的影响,利用残余力向量对损伤单元的敏感性,提出了广义残余力向量差的概念。为提高损伤识别结果精度和计算效率,联合采用广义残余力向量差定位与频率变化定量的结构损伤识别方法,先运用广义残余力向量差来初步确定损伤位置,再根据频率摄动运用测试精度较高的频率筛选计算损伤程度并确认损伤位置。实例证明,即使考虑测试误差,该方法仍然可以实现对损伤位置和程度的快速准确识别,具有较强的噪声鲁棒性。

According to matrix perturbation finite element method, a structural damage identification equation is derived. Using the sensitive properties of residual force vector to damage element, a concept of generalized residual force vector is proposed to reduce the effect of errors in modeling and measurements on identification results. To improve the accuracy of identification results and raise calculating efficiency, a combined method is used to identify structural damage based on the perturbation of frequency and generalized residual force vector. Firstly generalized residual force vector difference is used to locate possible damage elements, then damage elements and damage extent are determined by the perturbation of frequency which had high test precision. The example show that considering test errors, the method still could identify the damage quickly and accurately and has strong noise robusticity.