Study on mechanical behavior and optimization of frog-guard rail structure of double slip switches

As the key equipment in the throat area of railway yards, double slip switches are widely applied in railway hubs and marshalling stations due to their advantages of small occupation area and strong traffic capacity. However, their structure is complex, and under long-term operation, structural abnormalities are inevitable, which will affect the overall operational status of the equipment and is not conducive to the safe and smooth operation of the railway. Existing studies mostly focus on the defect treatment and macroscopic performance analysis of the whole turnout, while there are still deficiencies in the research on the failure mechanism and optimal design of frog and guard rail, the key load-bearing components. Combined with field working condition analysis, this paper systematically carries out research on the guard rail of double slip switches through field inspection, mechanism analysis, parameter optimization and finite element simulation. Firstly, the key accident-induced factors such as inconsistent specifications of guard rail bolts and insufficient width of flange grooves are analyzed. Secondly, targeted at No.9 and No.12 double slip switches with different straight passing speeds, the structural parameters of guard rail are optimally designed. The optimization schemes for the channel steel section of guard rail and connecting bolts are proposed, and the reasonable dimensions and fastener configuration of acute angle frog and guard rail are determined. The feasibility and rationality of the optimized scheme are verified via finite element simulation. The optimized guard rail presents clear improvements in structural stiffness, deformation resistance and bolt connection reliability.