An investigation into the causes of squats—Correlation analysis and numerical modelling

October 30, 2008 in

    Journal Paper

    Zili Li
    Xin Zhao
    Coenraad Esveld
    Rolf Dollevoet
    Maria Molodova

    DOI 10.1016/j.wear.2008.02.037


    Volume 265, Issue 9-10, Pages 1349–1355

    Publishing date: October 30, 2008


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    Nowadays squats are a severe rolling contact problem on some railways. The root causes of it are not yet clear. From railway operation and maintenance points of view, root causes have to be known so that effective maintenance policies and plans can be made based on measurements and prediction. In the present work first a correlation analysis is performed based on measured data and field observations, and then a relation between squat occurrence and some parameters of the vehicle–track system is identified. Subsequently a transient finite element model of vehicle–track interaction is built up to analyze the contact forces and the resulting stresses and strains. The numerical results show good correspondence with observed phenomena at squats, and suggest certain relation between squat development and some eigen frequencies of the coupled vehicle–track system. A squat growth process is accordingly postulated.