Abstract:
To optimize the structure of No.12 single turnouts of 60 kg/m rails, we conducted a study to address the issues associated with existing turnout switching design methods. By finite element simulation, we established a refined calculation model for turnout switching. The model can determine the plane alignment of a switch rail separated from the stock rail based on the actual force acting upon the switch rail. The obtained plane alignment was consistent with the actual situation, and was more reliable. Based on the established turnout switching model, the minimum flangeway width and dynamics between the strokes of the first and second traction points under different conditions were analyzed by numerical simulations. Accordingly, we proposed an optimized scheme that takes 160 mm and 90 mm as the stroke values for the first and second traction points, respectively. The scheme helped to meet the requirements for minimum flangeway width while making the deformation of the switch rail more even. Based on the proposed design method, trial production and laying of the new No.12 single turnout with a 60 kg/m rail was conducted, and a switching test was performed. The switching forces at the first and second traction points of the new No.12 turnout were approximately 2400 N and 3300 N, respectively, which were better than those of existing No.12 turnouts with 60 kg/m rails. Besides, the minimum flangeway width satisfied the requirement for safe vehicle passage with a safety margin of 3 mm~4 mm. The test results proved the effectiveness of the proposed turnout switching design method and parameter optimization scheme.