Optimization of Nose Depth for Rigid Frog

Based on wheel-rail contact relationship and dynamic interaction when wheel treads pass from wing rail to nose rail, a design and evaluation method for nose depth selection of key cross-sections was proposed to select reasonable nose depths for rigid frog. A train with LMA wheel treads passing over No.12 turnout of rigid frog in the facing move of the straight direction was taken as an example, and the optimization of nose depths was carried out by this method. The research results show that the nose depths of key cross-sections should not only satisfy the safety of wheel-load transition and the strength of nose rail, but also improve the train running stability. The smaller the nose depth, the smaller the wheel-rail interaction, which is helpful to improve the running performance, but whether the wheel-rail interaction location exceeds the scope of nose bearing capability should be taken into account. To a No.12 turnout of rigid frog, the optimal nose depths of the cross-sections with railhead widths of 20 and 50 mm should be 3 and 0 mm respectively.