Structure Health Monitoring Of Metro Vehicle Bogie Frame Using Lamb Wave

As the main bearer of urban traffic volume,rail transit increases with the increasing traffic volume.There are different degrees of fatigue in the concentrated parts,resulting in cracks,which eventually lead to component failure and threaten the safety of the vehicle.Therefore,this thesis introduces the concept of Structural Health Monitoring into the structural damage detection process of key parts of Metro vehicles,and proposes a Structure Health Monitoring of Metro Vehicle Bogie Frame usingGuided Acoustic Waves.The main contents are as follows:(1)In this thesis,the basic principle of guided wave,and the displacement of each mode in the structure,and explores the guided wave dispersion characteristic curve of isotropic materials are introduced.Based on the mechanical structure and material of the bogie frame,the piezoelectric is choosed.The piezoelectric is used as the sensor for activiting wave and collecting wave,and the coupling mode is discussed.Based on the sensor,the dispersion curve of the structure itself,the excitation frequency and excitation mode suitable for the material of the bogie frame are selected.(2)In order to study the actual propagation process and mode transformation of Guided wave in the bogie frame,ABAQUS is used to analyze the Guided wave propagation in the steel material,and the finite element simulation model of the bogie frame is established.Propagation modal transformation analysis,analysis of the mode wave energy in the framework,determine the excitation center frequency and mode of the bogie.(3)In order to localizing fautigue complex structures such as bogie frame,SSP algorithm,a wavelet localization algorithm based on Lamb wave is proposed.Compared with the traditional algorithm based on signal Hilbert envelope,this algorithm calculates a more accurate TOF.Direct time reversal imaging algorithm and synthesis time reversal imaging algorithm are also proposed to imaging the damage;(4)Finally,based on the Guided wave based metro vehicle bogie frame Structure Health Monitoring hardware system,Structure Health Monitoring of Metro Vehicle Bogie Frame using Guided Acoustic Waves is putted forward.The practical experiment find out it has a high Precision.