Analysis of a typical railway turnout sleeper system using grillage beam analogy

摘要

A simplified grillage beam analogy was performed to investigate the behaviour of railway turnout sleeper system with a low value of elastic modulus on different support moduli. This study aimed at determining an optimum modulus of elasticity for an emerging technology for railway turnout application - fibre composites sleeper. The finite element simulation suggests that the changes in modulus of elasticity of sleeper, E_sleeper and the sleeper support modulus, U_s have a significant influence on the behaviour of turnout sleepers. The increase in U_s from 10 to 40 Mpa resulted in a 15% reduction in the bending moment while the increase in E_sleeper from 1 Gpa to 10GPa has resulted in almost 75% increase in the bending moment. The shear forces in turnout sleepers is not sensitive to both the changes of the E_(sleeper) and U_s while the sleeper with low E_(sleeper) tend to undergo greater settlement into the ballast. An E_(sleeper) of 4 Gpa was found optimal for an alternative fibre composite turnout sleeper provided that the U_s is at least 20 Mpa from the consideration of sleeper ballast pressure and maximum vertical deflection. It was established that the turnout sleeper has a maximum bending moment of 19 Kn-m and a shear force of 158 Kn under service conditions.