结构模态参数的时序分析(ARMAV模型)识别法

Identification of Structural Modal Parameters by Time Series Analysis (ARMAV model) Method

本文简述了用时间序列分析(ARMAV 模型)识别结构模态参数的原理,对建模方法进行了分析,并对建模分析中至关重要的初值选择问题进行了讨论,提出了一种有效的初值的选取方法;在模拟计算部分中,用 Wilson-θ积分法模拟了一个三个自由度的振动和低信噪比、大阻尼振动和密集模态等复杂情形,对用时序方法(ARMAV 模型)识别模态参数的能力进行了检验;最后通过对实验数据进行有效的预处理后,用时序方法(ARMAV 模型)识别出一个真实结构(圆盘)的第一、二阶模态参数,并得到结构的完整振型.

In this paper,the principle of identification of structural modal parameters using Time series Analysis(ARMAV model)method are depicted.First,the modeling method and the choice of the initial values of model parameters are discussed,an effective choosing method is put forward.Then,the vibration of a system with three degrees of freedom and system with two degrees of freedom in low SNR,high damping and close mode case are simulated by Wilson-θ integration method,the ability of Time Series analysis(ARMAV model)to identify modal parameters is checked.At last,through effective preprocess of experimental data,the first and second modal parameters of a real structure(circle plate)are gotten by the Time Series Analysis (ARMAV model)method.