Research Base On The Hilbert-huang Transform For Health Detection In Plate Structure

In the field of Structural Health Monitoring(SHM),damage detection in plateStructures is an important research branch.Plate structural damage detection technologyis an important research content of structural health monitoring.This thesis investigatesthe detection of structural damage in aluminum plate structures using the empiricalmode decomposition(EMD) method along with the Hilbert spectral analysis and thetheory of Lamb wave propagation．This thesis first shows problems of Hilbert transform, and then give a briefdescription of the EMD and the Hilbert spectrum analysis, and Hilbert-Huang transformis proved in practical analysis of unsteady signal.Then,Lamb wave modes and dispersion phenomenon are analyzed, combined withthe experiment shows that the transmission characteristics of Lamb wave in thealuminum plate, through simulation to obtain the frequency dispersion curve inaluminum plate, and to provide theoretical basis for signal analysis.The experiment part, using the EMD and the Hilbert spectrum analysis method,through the analysis of Lamb wave in the plate structure,research the artificial hole inisotropic plate structure damage detection.This thesis uses the Lamb wave active health monitoring system,1millimeter thickaluminum plate as test object, the sensor receives the signal amplification and meanfilter, using the HHT method analysis of received signal, extract the damagecharacteristic parameters. Change the size and location of the damage, and throughcontrast and analysis the echo signal, implementing isotropic aluminum plate damagelocation and the size of the defect recognition.