基于残余力向量法和改进遗传算法的结构损伤识别研究

Study on structural damage identification based on residual force method and improved genetic algorithm

提出了一种基于残余力向量法和改进遗传算法的结构损伤识别方法。文中首先对残余力向量法和遗传算法的基本理论进行了介绍。在无噪声的情况下,使用任意一阶模态数据,残余力向量法都能够对损伤进行准确定位。但是,振动测试数据中往往包含噪声,导致运用残余力向量法进行损伤识别完全不可行。考虑到这个问题,在常规模态分析的基础上,以节点的残余力向量构造用于遗传搜索优化的目标函数形式,然后利用改进的遗传算法重点进行了噪声条件下的结构损伤定位和定量研究。最后,本文用一个平面桁架模型进行了数值模拟,验证了所提出方法的有效性,并对方法应用中存在的一些问题进行了深入分析,得出了一些有益的结论。

A combined method for the structural damage identification based on the residual force method and improved genetic algorithm is presented. Firstly, a brief introduction of the theory of the residual force method and genetic algorithm （GA） is included. Then, the residual force method is employed to localize the damage, which can accurately locate the structural damage using any order of the modal data without noise. Noise, however, can not be avoided during the dynamic measurements, which leads to the identification of the structural damage completely impossible. Secondly, considered this problem and based on the conventional modal analysis theory, the localization and quantification of the structural damage under the condition of noise are further performed with improved GA implemented by an objective function formulated by the nodal residual forces. Finally, an illustrative example of a plane truss model is given in order to demonstrate the effectiveness of the proposed method. Some problems encountered in this method are analyzed and some concluding remarks are given.