Study on factors affecting the resonance fracture location in e-type fastener clips

Abstract

In this study, the natural frequencies and influencing factors of the e-type fastener clips were first analyzed through modal simulation and hammer impact test, and combined with the vibration frequency caused by rail corrugation, the modal resonance order was determined. Then, the stress field of the e-type fastener clips under inertial loads from each resonant mode was simulated, exploring the impact of the increasing proportion of inertial loads in different directions on fracture locations. Finally, a fatigue testing method employing equivalent preloading of resonant inertial loads was applied to reproduce fracture locations under various resonant modes. The results show that the friction coefficient between the clip's toe and the gauge block significantly impacts the 2nd-order natural frequency of the e-type fastener clips, which is associated with its modal lateral vibration. When the friction coefficient drops to about 0.1, on the distal side where the gauge block moves toward the iron plate support, this frequency of the e-type clips decreases by 363.2 Hz compared to conditions without trainload, causing simultaneous 1st-order and 2nd-order modal resonance. If the growth ratio of vertical inertial loads exceeds that of lateral loads, fractures occur at the arch heel; conversely, fractures occur at the front arch.