AR時系列解析を用いた非対称非線形振動系の同定

抄録

This paper discusses a new method for identifying asymmetric nonlinear vibrating systems. To understand the current status of infrastructures through their asymmetric and nonlinear vibrating behavior, system identification for those vibrating systems is very important. Identification problem of nonlinear stiffness parameter (not including asymmetricity) in vibrating systems can be solved by a method of averaging. The authors proposed such a method in a previous paper. However, there is a problem that conventional methods including the one in the previous paper cannot address the sign of nonlinear parameters and identification of asymmetric vibrating systems. Therefore, this paper proposes a new system identification method to solve these problems by identifying appropriate sign of nonlinear parameters based on movement of center-of-vibration. In this paper, identification experiment is conducted using numerical investigation, Runge-Kutta method. A nonlinear coefficient is considered in two cases: positive number and negative number. In both cases, the proposed method gives good estimated results which show good agreement with the true values when there is sufficient number of data samples available for system identification, e.g. more than 600 samples. On the other hand, estimation error in identification increases when there is small number of data samples less than 200 or data samples have small amplitude.