Optimization Design for Internal Structure of Embedded Rail Trough

Embedded ballastless tracks are stable, low maintenance, and good at shock absorption and noise reduction, such that it accommodates the requirements of urban rail transit operation, and has been widely used in the construction of modern tram lines. Owning to the structural characteristics of embedded tracks, its optimization focuses on the trough structure and the polymer composite covering the rail. In this work, the static and dynamic behaviors of embedded ballastless tracks are analyzed by using the finite element software ANSYS. On the basis of topology optimization, given the requirements of cost, safety, noise, and vibration on the urban rail transit, the structure of embedded rail trough is optimized. The results indicate that less composite material at the junction of embedded rail waist and bottom saves the cost while guaranteeing track stiffness. Instead of being lowered in height, polymer composite material should cover the rail completely to decrease the noise and vibration. The width of the bearing slot should range between 200 and 220 mm at normal parts. Increasing the width of the bearing slot is the most effective measure to reduce the vibration in the areas subject to strict vibration requirement. The elastic modulus of the composite material should be chosen to ensure the track transverse stiffness and reduce the stress level of concrete track slab.