Research on track damage identification based on the response of vehicle-rail contact point

In this paper, spring element is used to simulate the vertical support of ballast and sleepers to the rail, which is called “elastic support”. Low-pass filtering technology was adopted to extract the response of the driving frequency component in acceleration signal of the contact point between vehicle and rail, and Hilbert transform was carried out on it to obtain instantaneous amplitude squared (IAS) information to judge the damage of rail and elastic supports through the peak values in the IAS identification diagram. Based on this principle, the crack damage of rail and stiffness damage of elastic support are studied, the applicability of IAS method for the rail and elastic support under different damage degrees and damage amounts is analyzed, and the influence of parameters such as vehicle speed, vehicle damping ratio, vehicle mass and frequency, track damping and rail irregularity on IAS damage location method is discussed. The results show that the IAS method can accurately identify the damage of elastic support and rail under different damage locations and different damage degrees. Under proper vehicle speed, the IAS method can accurately locate the damage; The influence of vehicle frequency on damage identification results is small. With the increase of vehicle damping ratio, the amplitude of IAS results decreases, while track damping has almost no effect on damage identification. Due to the existence of track irregularity, the damage signal collected by test vehicle may be covered by irregularity, and the interference of track irregularity can be reduced by increasing the mass of test vehicle. © 2022 The Author(s)