Study on the crack propagation performance of the critical position of the train body beam

High-speed EMU chassis beam commonly used aluminum alloy extrusion profiles, a large number of equipment mainly by bolt with hanging in the car body chassis beam, the equipment weight and vibration generated when the train running load (embodied in near a load average change of random load) through the bolt is passed on to the beam, easy cause fatigue fracture of beam structure, influence the safe operation of vehicles In this paper, the stress spectrum of 20 measuring points on the key position of the beam is obtained based on five actual tests of dynamic stress of the beam. According to the principle of equal damage, the stress spectrum of each measuring point is equivalent to the equivalent stress data of the actual operating mileage of the vehicle, so as to obtain the load imposed by the fatigue analysis. Secondly build body in ABAQUS finite element model of beam and bolts with substructure, the method of using extended finite element by default the initial crack constraints and applying different amplitude cyclic load simulation of the propagation of the crack, and research and analyze the law of crack propagation, for high-speed emu overhaul and damage tolerance design to provide advice and reference.