Study on Load Spectrum Compiling Method of Wagon Carbody Fatigue Test

C70 carbody is taken as the research object.The car body load data is obtained by load test as well as the stress data of fatigue critical parts.The method of utilizing the measured data for compiling fatigue test load spectrum is studied,and the way of using relationship of carbody load and stress response for compiling fatigue test load spectrum is put forward.According to the damage equivalent principle,the small stress cycle which has no contribution to carbody damage is cut out,and stress time history is simplified and concentrated.By using synchronicity of load and stress test,load time history is concentrated as well.Combining with the cumulative damage theory,the carbody fatigue damage before and after concentration is analyzed in comparison.The feasibility and accuracy of this method is verified.