基于弯沉斜率的CRTS-Ⅱ板CA砂浆层脱空长度评估方法OA北大核心CSTPCD

There is a lack of an effective assessment index for quantitative detection of disengaging in the cement asphalt mortar layer when trains are in motion,and the detection methods based on track/vehicle response characteristics and track alignment changes are based on qualitative judgment.In order to solve the above problems,the quantitative assessment study of the disengaging length under various conditions was carried out by adopting the deflection slope as the assessment index of the disengaging length.First,based on Euler Bernoulli beam theory and Winkler model,the relationship between deflection slope and deflection velocity of the track plate was deduced,a vehicle-track finite element dynamics model was established,and a variety of different disengaging lengths were set.Second,the distribution of deflection velocity in specific areas of the track plate surface when the train passes through the affected area at different speeds was studied,and the spacing between the location where the maximum deflection velocity of the track plate appears in this process and the wheelset center was obtained.Third,the optimal deflection velocity measurement position was solved based on the linear decreasing particle swarm optimization algorithm.Finally,the variation law of the deflection slope and its correlation with the disengaging length were analyzed.The results show that:the deflection slope is positively correlated with the disengaging length.So,the deflection slope can be used not only for the identification of mortar layer disengaging,but also for the quantitative assessment of the disengaging length.The optimal position for measuring the deflection velocity under different disengaging conditions is 2.4 m in front of the center of the train wheelset,and the corresponding deflection velocity at this position can more effectively reflect the influence of disengaging.The average value of the mean absolute percentage error of deflection slope is 13.7%at different speeds,and that of deflection speed at the corresponding position is 112.93%.This reveals the variation law of deflection slope under different disengaging conditions,and gives the reference range of deflection slope variation under seven disengaging conditions.