EFFECTS OF RAIL GAP ON WHEEL-RAIL CONTACT STRESSES

An elasto-plastic finite element model of wheel-rail contact at rail end is established using the finite element package ANSYS.Variations of stresses and deformations of rail material with the distance from the wheel-rail contact point to the rail joint are investigated.The numerical results are also compared with those from Hertz contact theory.The results show that the Mises equivalent stress,the maximum shear stress,the plastic zone size and the deformations increase with a decrease in the distance from the contact point to the rail joint.The maxim equivalent stress and shear stress occur close to the rail surface if the wheel-rail contact point approaches the rail joint.Because the rail geometry at rail gap does not satisfy the assumption of Hertz contact theory,Hertz contact theory is not suitable for the contact stress analysis when the wheel-rail contact occurs near the rail end.