Behavior of bolted connections in railroad diamond crossings

Maintenance and replacement costs of special track work elements are an expensive problem for the railroad industry. In the railroad industry, special track work refers to special railroad elements, including turnouts, switches, and diamond crossings, that are used where rails join or cross. The repeated impact and dynamic loads that diamond crossings are subjected to result in alignment problems and more rapid deterioration of the special track work elements compared to open track. This research project aims to perform finite element analysis of a diamond crossing frog in order to observe the behavior of diamond crossing bolted connections and to provide suggestions for improving their performance. The ABAQUS environment is used to create and analyze the finite element model. A standard rail joint is modeled with shell elements in order to gain background knowledge on the performance of simple bolted connections in rail. The analysis of one crossing frog in a typical diamond crossing is then performed, again using shell elements. Static, linear elastic analyses were performed using amplified vertical wheel loads to approximate the dynamic effects. The crossing frog model is used to perform a parametric study that evaluates the relative influence of a variety of diamond crossing properties on the behavior of the diamond bolted connections. The results show that the longitudinal rail loads, vertical load position, and foundation stiffness significantly influence the stresses in bolts and connected elements