非线性结构系统的局部连接刚度辨识方法研究  

Local connection stiffness identification for nonlinear structural systems

作　　者：任彦松 马志赛 李亚南 于佳晖 张忠[3] 丁千[1,2] REN Yan-song;MA Zhi-sai;LI Ya-nan;YU Jia-hui;ZHANG Zhong;DING Qian(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Tianjin Key Laboratory of Nonlinear Dynamics and Control,Tianjin 300350,China;Beijing Institute of Structure and Environment Engineering,Beijing 100076,China)

机构地区：[1]天津大学机械工程学院,天津300350 [2]天津市非线性动力学与控制重点实验室,天津300350 [3]北京强度环境研究所,北京100076

出　　处：《振动工程学报》2024年第10期1698-1706,共9页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(12272258,11802201);北京强度环境研究所联合创新基金资助项目(BQJJ202307)。

摘　　要：连接结构在工程应用领域广泛存在,连接位置处的局部非线性特征对结构系统的动力学建模与特性预示具有重要影响。针对非线性结构系统局部连接参数未知或难以测量的问题,本文从结构动力学反问题的角度出发,提出一种基于频响函数变换的局部线性连接刚度辨识方法,通过与时域非线性子空间辨识方法相结合,可进一步获取非线性结构系统的局部线性和非线性连接刚度。设计并搭建三自由度结构系统的数值算例和实验系统,开展辨识方法的数值和实验验证,结果表明,所提方法能够分离并辨识得到非线性结构系统的标称线性系统频响函数和非线性参数,进而实现局部线性和非线性连接刚度的联合辨识。Jointed structures are widely used in engineering applications,and local nonlinear characteristics at the connection interface have an important influence on their dynamic modeling and characteristic prediction.Aiming at the problem that local connection parameters of nonlinear structural systems are unknown or difficult to measure,this paper proposes an identification method of local linear connection stiffness based on the FRF transformation from the perspective of inverse dynamic problems.By further combining with the time-domain nonlinear subspace identification method,the local linear and nonlinear connection stiffness of nonlinear structural systems can be finally obtained.The numerical example and experimental setup of the three degrees-of-freedom structural system are designed and further built to validate the proposed method.The results demonstrate that the proposed method can separate and identify the underlying linear FRF and nonlinear parameters of the nonlinear structural system,and subsequently realize the joint identification of the local linear and nonlinear connection stiffness.

关 键 词：连接刚度辨识 连接结构 非线性系统 非线性子空间辨识方法 

分 类 号：O327[理学—一般力学与力学基础] O322[理学—力学]