Improved Method for Calculating the Gauge of Railway Vehicles Considering the Non-Linearity of Suspension Systems

Abstract

An improved method for calculating the gauge of railway vehicles is proposed in this study, which can provide more reasonable results for vehicles with nonlinear springs in the suspension system. Typical mechanics models of nonlinear springs are built and then introduced into the calculation formulas described in the Chinese Gauge Standard CJJ 96-2018. The relative displacement equations for the primary and secondary suspensions are defined, based on the calculation formulas, and an iterative algorithm based on Taylor expansion is applied to solve these nonlinear equations. By solving the equations, the relative displacements of the control points of the suspension system are obtained and the parameters for gauge calculation are updated. The updated parameters are then used to calculate the transverse and vertical displacements of the car body, bogie, unsprung components, flange, and tread, and to determine the quantity of throw of the vehicle profile. Finally, a numerical example is given to verify the feasibility, accuracy, and applicability of the method, and the results are also compared with those calculated from European Standard EN 15273. The method is applicable to a wide range of railway vehicles with nonlinear suspension systems, giving more reasonable results compared with existing calculation methods.