基于不完备实测模态数据的结构损伤识别方法研究  

Structural damage detection method using incomplete measured modal data

作　　者：李世龙[1] 马立元[1] 田海雷[2] 李永军[1] 

机构地区：[1]军械工程学院导弹工程系,石家庄050003 [2]武汉军械士官学校光电装备系,武汉430075

出　　处：《振动与冲击》2015年第3期196-203,228,共9页Journal of Vibration and Shock

基　　金：军队科研资助项目([2012]80)

摘　　要：在传统的基于模型修正的损伤识别中,由于实测模态信息有限而待识别参数过多,往往导致损伤识别方程出现较大误差,从而限制了该方法在复杂结构中的应用。为解决这一问题,对结构的自由度进行了分解,将损伤结构中模态振型的未测量部分表达为已测量到的模态振型、模态频率以及结构其它参数的函数。将损伤视为结构单元刚度的减小,利用完好结构的计算模态数据以及损伤结构扩充后的实测模态数据,建立了结构的损伤识别方程。运用信赖域优化算法对具有双重约束条件的目标函数进行最小化,识别出了结构各单元的刚度损伤参数。通过两个损伤识别数值仿真算例及实验验证,结果表明,在测点数量有限及测试噪声等不利因素影响下,所提方法只需运用少量的实测模态信息,即可实现结构损伤位置及程度的准确识别,同时算法具有较好的鲁棒性。Owing to that the measured modal data is far less than parameters to be identified and the damage identification equations always have larger errors,these lead to the application of the traditional damage detection based on model updating is always limited in complex structures.Here,the drawback was solved by dividing structural DOFs into measured and unmeasured parts.Meanwhile,the unmeasured parts of the modal shapes of the damaged structure were characterized as a function of the structural parameters and the modal shapes of measured parts.Considering damage as a reduction of element stiffness,then the calculated modal data of an intact structure and the measured modal data of the corresponding damaged structure were used to establish the damage detect equation.The dual constrained objective function was minimized to recognize the changes of structural parameters by utilizing the trust region optimization method. The proposed method were verified with two numerical simulation examples and a damage detection test.The results showed that the proposed method has a good ability to detect any damage of structures using incomplete measured modal data,and the algorithm also has a good robustness.

关 键 词：模态数据 模型修正 目标函数 信赖域 鲁棒性 

分 类 号：TB123[理学—工程力学] TU311[理学—力学]