The Corbel Fatigue Strength Of CRH-2EMU Based On The Measured Load

With the high-speed-development of the railway, the high-speed Electric Multiple Units are playing a more and more important role. The body, acted as a key component of EMU, takes a very important position in the design of EMU.This paper conducts static strength analysis, fatigue strength analysis and modal analysis with the method of finite element simulation, and then carries on the dynamic stress tracking test of sleeper beam to evaluate its security features with the measured data. Also, considering aluminium alloy stress corrosion effect, based on the fatigue strength and fracture mechanics theory, the weld crack initiation life and propagation life the key parts of train body pillow beam was calculated, and the train key parts fatigue life and cumulative damage value is obtained. The main work is as follows:(1) Establish the3D CAD model on the basis of drawings and do the meshing work. and then accomplish finite element simulation analysis according to relevant technical standards and regulations, mainly containing static strength analysis, fatigue strength analysis and modal analysis. And it judges whether static strength, fatigue strength and modal frequency of the body sleeper beam.(2) It conducts tracking test of dynamic stress based on results of FEM simulation and data collection of dynamic stress. According to dynamic stress, it carries on the research on fatigue damage and the change trend of cumulative damage with the increasing running miles, combined with Miner cumulative fatigue damage rule.(3) In combination with stress corrosion mechanism and the aluminum alloy material p-S-N curve in corrosion environment and Paris formula, carried on the calculation of the crack initiation and propagation life in the key parts of train body under the measured spectrum; and the analysis of the impact on body pillow beam area crack initiation and crack propagation of crack corrosion degree in different positions(4) Applying the equivalence stress of finite element technology method to the structure stress analysis of the key weld in corbel, extracts the node force and torque of weld toe to calculate the structural stress. Under the guidance of Paris crack extension theory, combined with the related materials in ASME standard master S-N curve, the fatigue life of the pillow beam weld structure is evaluated.