Dynamic Responses Due to Different Sub-rail Stiffness of Bolted Alloy Steel Frog

The sub-rail stiffness of bolted alloy steel frog has a great influence on impact load of rail head and rail internal tensile stress. So it is very essential to optimize the sub-rail stiffness and carry on a fatigue calculation on weak frog components to guide frog design. Taking No.12, bolted alloy steel frog, single-way turnout as an example, the rules of frog stresses and deformations influenced by different sub-rail stiffness under the train dynamic load were analyzed and compared based on the finite element method, and carried on a fatigue calculation on the weak zone of the frog centre. It turned out that as the sub-rail stiffness increases, the rail impact load by train increase, and rail tensile stress and vertical deformation both decrease. A proposal sub-rail stiffness is 50kN/mm; The maximum fatigue stress appears in the zone where the frog centre sections change greatly, so the nose rail structure in this zone should be optimized.