基于NARMAX模型和NOFRF结构损伤检测的实验研究

摘要

The nonlinear output frequency response functions(NOFRF) which is derived from the Volterra series can facilitate the analysis of nonlinear systems in frequency domain,it is a one dimensional function of frequency.The paper introduces the structural damage detection method which is based on NARMAX model and NOFRF.An experimental study demonstrates the feasibility of the structural damage detection method.Because the nonlinear characteristics of system can be used for the detection of structural damage,and is sensitive about the state of system,in addition,the structural damage detection method which is based on NARMAX model and NOFRF is a nonlinear method for analyzing the state of system,the characteristics extracting from system is a nonlinear characteristics,so the damage detection method can be used for the detection of structural damage,and has the advantage which is sensitive to the state of system.%非线性输出频率响应函数是由Volterra级数发展而来的频域概念,可方便在频域对非线性系统进行分析,它是频率的一维函数.本文主要介绍了利用NARMAX模型以及NOFRF对结构进行损伤检测的方法,并利用实验研究证实了该损伤检测方法的可行性.另外,由于系统非线性特性可用来做结构损伤检测,且具有对系统状态比较敏感的优点,而基于NOFRF的损伤检测方法是利用非线性方法来分析系统的状态,该方法提取出的特征属于非线性特征,所以该损伤检测方法可以用来做结构损伤检测,且具有对系统状态比较敏感的优点.