A Fast Wheel-Rail Forces Calculation Computer Code

Creep forces in simulations of traction vehicles running on adhesion limit

“…The method developed by the author for calculation of creep forces in multi-body simulations [8,9] is based on a theoretical model for longitudinal and lateral creep assuming a coefficient characterising the contact shear stiffness. The basic idea is to integrate the shear stress distribution over the contact surface to obtain the magnitude of the resultant creep force F. The different creep force components F x , F y are assumed to be proportional to the longitudinal and lateral creepages.…”

“…A possible explanation of the decreasing section of creep force-creep function for large longitudinal creep is the 0043 Greek letters ε gradient of the tangential stress in the area of adhesion ε x gradient of the tangential stress in longitudinal (x) direction µ coefficient of friction µ 0 maximum friction coefficient at zero slip velocity µ ∞ friction coefficient at infinity slip velocity σ normal stress τ tangential stress τ max maximum tangential stress υ x non-dimensional longitudinal creep, see [9,28] for definition decrease of friction coefficient with increasing slip velocity due to increasing temperature in the contact area [1][2][3][4][5]. Another explanation -different friction coefficients in the area of adhesion and area of slip (static and kinematic friction coefficient) -does not seem to sufficiently influence the shape of the creep force curve [6,7].…”

A study on the critical speed of worn wheel profile using a scale model

“…(6) show equation of the bogie [10][11][12]. To calculate the creep forces at contact points, Oldrich Polach's algorithm was applied [13]. …”

Application of Uniform Design and Quantum-behaved Particle Swarm Optimization in Solving the Sensitivity Problem a Railway Vehicle System

“…For studies on the dynamic stability of a vehicle running on curved tracks, a car is generally modeled by systems of various degrees of freedom with traditional linear and nonlinear creep model. Molatefi et al [1] and Polach [2] investigated the dynamic responses and critical speeds of railway vehicle with both linear and nonlinear creep models. Little attention has so far been given to the robustness of critical hunting speed.…”

“…a half of track gauge a , b semi-axis lengths b 1 half of primary yaw spring arm and primary yaw damping arm b 2 half of secondary longitudinal spring arm b 3 half of secondary longitudinal damping arm C ij creepage and spin coefficients C px , C py yaw and lateral damping of primary suspension C sx , C sy yaw and lateral damping of secondary suspension f coefficient of friction between wheels and rails f 11 lateral creep force coefficient f 12 …”