Investigation of fatigue life of draw hook equipment used in freight wagon: Miscellaneous result

Abstract

The coupling set, exposed to multi-directional severe dynamic loads, is a vital part that connects the wagons in rail system vehicles. These loads are usually transferred through the hook body in the draw hook coupler variant. Recently, some researchers have suggested that draw hook equipment suffers from fatigue damage if periodic maintenance is not performed correctly. For this reason, transportation safety is in danger. This study investigated fatigue occurring in the draw hook body and other metallurgical and mechanical properties affecting fatigue experimentally and numerically. The microstructure characterisation of the material was made using optic microscopy, electron spectrometry and scanning electron microscopes. The Brinell hardness and tensile test examined the material's mechanical properties. The fatigue behaviour rotating bending test and the complex S-N curves were obtained. For the computer validation of fatigue behaviour, stress life and strain life fatigue analyses were carried out using a commercial ANSYS program package. The high and low cycle fatigue regions are highlighted in the S-N curves. The endurance limit for the stress of 424.6 MPa was determined at 1.3 × 107 cycles.