Study on Key Technology of Railway Freight Car Body Fatigue Test

Car body fatigue reliability is a key technology for the development of railway heavy axle load freight cars. Therefore, a comprehensive test rig capable for carrying out car body fatigue test and complete car vibration test was designed and built in CRRC Qiqihar Rolling Stock Co., Ltd. (QRRS). This test rig was used to validate fatigue life of car body in accelerated fatigue test by simulating car body movement in service with input data derived from measurements in service lines. The success of such test depends on some key technologies such as collection of response signals in service line test, process of data collection, compilation of drive file for test rig, determination of test methods and evaluation of test results. A C70E-loaded general service gondola car was tested on test rig to evaluate its fatigue life with accumulated equivalent total mileage of 3.125 million kilometers. The test results indicate that this car body can survive for 25 years and meet designed life requirement. Comparison between response signals from test rig and target signals demonstrates that acceleration RMS error is less than 6%, and stress RMS error is less than 18% and fatigue accumulated damage error is less than 6%. It means that simulation accuracy of test rig has achieved the requirement. Such results demonstrate that related key technologies are applicable and suitable.