Analyses of Fractures that have Caused Traffic Accidents

The paper analyses some fractures of vehicle componentswhich have caused traffic accidents. The methods of analysingthe cause of fracture have been described, as well as the maintypes of fractures. The first analysed cause of a fracture is the excessivelyrough machine finish which leaves cracks (stress concentrators),the starting points of crack propagation. The secondcause is unprofessionally per[01med welding which later inservice causes fracture at the weld. The third cause is the toohigh content of carbon in the material of the railway vehiclewheel rim. Dwing braking, the higher content of carbon causedformation of excessively hard (and brittle) martensite in thesurface layer of the rim.