The hoisting and transfer of electrical equipments such as transformers are weak links that are neglected in monitoring

and secondary damage caused by mechanical impact is very easy to occur.The impact response of transformer rail transit vehicle caused by subgrade vibration was studied.Firstly

the rail transit vehicle transformer coupling analysis model was established

and the response area of the rail transit vehicle transformer coupling analysis model under the action of subgrade vibration was obtained by finite element analysis.Then

a non⁃periodic transient response feature extraction method based on wavelet dispersion entropy was proposed.This method performed good sparsity segmentation of the whole frequency band through the optimal subband tree structure of wavelet packet

decomposed the one⁃dimensional data containing a variety of information into different dimensions

and realized the effective decomposition of signals.The impact characteristics of subband signals were enhanced by Teager energy operator(TEO)

and the subband signals with impact response characteristics were selected by dispersion entropy.Finally

through the subgrade vibration simulation signal

it is verified that the proposed method can accurately extract the aperiodic transient impact response components from the coupling path interference.