Summary: | In view of the fracture and edge crack initiation of the bogie cowcatcher during the service of a metro train,the failure causes are analyzed,and a fatigue performance evaluation method combining finite element analysis and dynamic stress test is proposed to verify the rationality of improving the structural design of the cowcatcher.Firstly,the structure of the cowcatcher with fracture or edge crack is analyzed in the aspects of design,structure,manufacturing and raw materials,and the corresponding structural improvement scheme is proposed.Secondly,the static strength and fatigue strength of the structure for the new cowcatcher are analyzed to clarify the dangerous parts according to the EN13749 standard.Thirdly,determine the strain gauge layout plan and conduct line tests considering the simulation analysis results and the operating space comprehensively.Finally,the fatigue performance evaluation of the cowcatcher is carried out by miner’s linear cumulative damage rule and IIW recommended S-N curve.The results show that the fatigue performance of the new type of cowcatcher based on finite element analysis and dynamic stress test meet the requirements,and the two support each other to further verify the rationality of the new structure design.Simultaneously,the simulation analysis results provide a theoretical reference for the reasonable arrangement of measuring points.
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