Abstract: Bogie frame is one of the main load-bearing components of rolling stock, its structural reliability and wheel-rail force interact with each other. By establishing rolling stock rigid-flexible coupling model, the stress level of the bogie frame in different working conditions is analyzed, the bogie frame stress level changes before and after the structural improvement and the impact on the vehicle operation safety are studied. The results show that after structural reinforcement, the stress level at the connection between the base of the positioning arm and the lower cover plate decreases significantly. With the increase of train running speed, the stress improvement effect decreases gradually. In addition, the derailment coefficient and wheel load reduction rate under the improved frame have no significant change, but the value decreased, which indicates that the improvement of frame structure can improve the train operation safety.

Key words: Train Operation Safety; Wheel-rail force; Structural strength; Stress level