Fatigue Analysis Of The Welding Bogie Frame

Nowadays with the raising speed of railway vehicle, the phenomenon of the fatigue failure of the welding area has been seriously, and the welding fatigue strength has been an important factory of influencing the reliability of the key parts of railway vehicle. The evaluation of the fatigue strength has entering into super-high life when the bogie frame is working in high speed for a long time. The assessment of the fatigue strength has been one research focus which involved the welded structure.In this thesis, the fatigue evaluation of the welded structure has been systematically accomplished, which base on the fatigue experiment of the welded sample in super-high life, with the integration of the finite element analysis and the fatigue analysis. It can offer one way for the fatigue strength evaluation of the welded structure of the frame.The welded samples'models have been built with the ANSYS software, then conduct quasi-static analysis wit unit load. And the evaluation of the samples'fatigue has been accomplished with the FE-Fatigue module of the nSoft software. The fatigue experiments of the samples in super-high life have been finished based on the simulation analysis that includes one-side welding cruciform joint, double-side welding cruciform joint, vertical joint and strengthening tendon-plate joint. The corresponding curves of Goodman and S-N and fitting equation of the S-N curve have been got from the fatigue experiments. The basic data has been provided for the fatigue strength assessment of the welded structure.This thesis evaluated the fatigue life of typical welded bogie applying the result of the fatigue experiment of the welded sample in super-high life. The dynamic load acting on bogie has been obtained by using the dynamics simulation programe-SIMPACK. The bogie frame of the finite element and sub-model of severe damaged partial has been built with the consideration of the welded seam. The fatigue life has been predicted in different application condition. Therefore theoretical basis has been supplied for the optimization design of the bogie frame.