Research On The Influence Of Structure And Stability On The Structural Strength Of 209P Bogie Frame

Bogie frame is one of the main bearing parts of the railway vehicle, and its structural strength is very important to the train operation safety. In recent years, cracks have appeared frequently in the beams connecting section of 209P bogie welded frame during the application process, which has a serious impact on the train operation safety.In view of this, the paper combines the vehicle dynamics with finite element analysis to study the influence of frame structure and vehicle stability on the structural strength of 209P bogie frame, and focuses on the stress level of frame beams connecting section. This article established rigid flexible coupling dynamic model of vehicle based on the frame of elastomer with SIMPACK software, and simulated to obtain the load time history of frame under different operation condition, improved model frame, different suspension parameters, then did the frame dynamic stress analysis by the finite element analysis software ANSYS, while introduced average stress amplitude to compare and analyze the stress level of nodes in the beams connecting section. The research was supported by the following conclusions:(1) The stress level of nodes in the beams connecting section is improved with the increase of running speed of the vehicle. During the long term service, the site may appear fatigue damage, which has greatly influenced the application safety of bogie frame. In addition, under vehicle instability state the derailment coefficient and wheel/rail lateral force exceed the safety limit, which seriously affects the train operation safety.(2) Under the same velocity, the stress level of nodes in the beams connecting section is obviously decreased under improved frame. During the actual operation, the improved frame can reduce the possibility of occurrence of fatigue and damage in the beams connecting section. In addition, the derailment coefficient, wheel load reduction rate and wheel/rail lateral force under the improved frame have no significant change, but the value decreased, which indicates that the improvement of frame structure can improve the train operation safety.(3) By changing the suspension parameters, the nonlinear critical speed of the vehicle is increased, and the derailment coefficient, wheel load reduction rate are decreased. At the same time, the stress level of nodes in the beams connecting section is decreased at the same speed.(4) Under the premise of satisfying the safe operation of the vehicle system, by improving the frame structure or optimizing vehicle system suspension parameters can reduce the stress level of nodes in the beams connecting section, and reduce the possibility of occurrence of frame fatigue and damage, and improve the application safety of bogie frame.