Abstract: At present, the maximum operating speed of China's independent development renaissance EMU has reached 350 km/h in Beijing-Shanghai high-speed rail, with the speed increase, EMU frame fatigue research is increasingly important. Through the dynamic stress test of the bogie frame of the EMU, it is found that stress level of the key points under curve condition and turnout condition, compared with the straight-line condition, have their own characteristics. Based on MEMS gyroscope, GPS and rail line parameters, after several months of testing a certain type of EMU frame, the stress data of the measuring points under different working conditions are extracted, statistically analyzed and calculated. The results show that most of the measuring points have a certain increase in stress level when passing through the curve, and the stress level is greatly increased at the time of passing through a turnout. While comparing the stress data at different locations, it can be found that the response to specific conditions, such as curve condition and turnout condition, measuring points at the joint between cross-beam and side-beam of the frame are more sensitive than the measuring points near the center of the frame. The above conclusions provide experimental basis for the research on load spectrum of different working condition and also give some suggestions for the line design of combined with frame damage.

Key words: EMU, equivalent stress, frame, sensitivity, working conditions