基于耦合系统环境振动试验的结构和TMD参数识别

Parameter identification of structure and TMD based on ambient vibration tests of the coupled system

为了实现TMD现场调试,提出了一种通过测试结构-TMD耦合系统的环境振动响应,识别结构模态频率、阻尼比和模态质量以及TMD的频率和阻尼比的方法。该方法通过测试环境激励下结构和TMD的响应,采用随机子空间算法,评估离散状态矩阵;将离散状态矩阵减缩和转化成单自由度结构和TMD耦合连续状态矩阵;并根据连续状态矩阵评估质量比、结构和TMD的固有频率和阻尼比。数值仿真分析结果发现:①该方法可行且识别结果精度高;②该方法适用于多模态振动结构。单层框架试验研究验证了该方法的有效性。

A method was proposed to identify the mass ratio and the natural frequencies and damping ratios of a structure-TMD coupled system based on ambient vibration tests.First,the discrete state matrix was estimated from ambient vibration tests by the stochastic subspace identification method.Then,it was transformed into the continued state matrix of the single degree-of-freedom’s structure and TMD coupled system.Final,the mass ratio,natural modal frequencies and damping radios were identified based on the continued state matrix.Numerical analyses were carried out and the results indicate that the method is reliable and suitable for multi-degree-of-freedom structures.The tests were performed on a laboratory set-up and the viability of the method and its suitability for real applications were assessed.