Model‐based method with nonlinear ultrasonic system identification for mechanical structural health assessment
Hanxin Chen, Lang Huang, Yang Liu, Yongting Chen, Jinmin Huang
Abstract
Abstract Conventional methods for the structural nondestructive testing (NDT) such as pulsed eddy current (PEC), ultrasonic detection (UT), and so on are based on the output signal interpretation technique of the NDT system to extract the features to assess the structural health. In this article, a novel NDT method for the structural health monitoring from the different perspective is proposed, which is based on the structural system model between the exciting input and output response. Nonlinear autoregressive moving average with exogenous inputs (NARMAX) is used to establish the time domain model between the input signal and the output response. Frequency response (FRF) of NARMAX model from the time domain data is proposed to obtain the indicators to assess the structural health. The effectiveness and advantage of the proposed method are tested with two sets of experimental data by comparison with the existing method.