Research On Array Error Model And Compensation Methods For Impact Source Localization On Composite Material

Composite materials have the advantages of light weight,high specific strength and.specific modulus,and strong corrosion resistance.They are the most important aviation materials besides aluminum.However,composite materials are very sensitive to external impact loads,and real-time on-line impact monitoring has become a very important topic in composite structure health monitoring.The piezoelectric array structure health monitoring method based on Lamb wave has the advantages of small damage sensitivity,long distance propagation and large area monitoring.At present,structural health monitoring methods based on array signal processing rely on accurate array steering vector.In practical engineering applications,the existences of those array errors were touched off by various unavoidable factors such as array element position deviation,time-varying environment and different propagation path,which lead to the deviation or perturbation of the actual steering vector in a certain extent.Therefore,array error is considered as the bottleneck of array signal processing technology to engineering application.This paper focuses on the application of piezoelectric array error modeling and compensation method in composite structure health monitoring.The main research work is divided into the following aspects:(1)Aiming at the problem of position deviation of array element in piezoelectric sensor array,the amplitude and phase error model of array signal is established,and the impact location method based on adaptive array error correction is proposed,which makes the accuracy and resolution of impact location were effectively improved.(2)Due to the influence of time-varying environmental factors such as temperature,vibration and stress on Lamb wave array signal,the amplitude and phase error of array signal caused by time-varying environment is analyzed,and a compensation method based on impact localization of composite structures is proposed in time-varying environment,which result in the influence of time-varying environment was effectively reduced on impact localization.(3)To deal with the problem of array error caused due to the inconsistent signal propagation path in the stiffened composite plate,the array error matrix model is constructed by finite element simulation,and the array error compensation method for impact localization of reinforced composite structure is proposed,which bring about the accurate location of complex composite structure was realized.