THE CAUSE EXAMINATION OF THE CRACK OF THE END BEAM FOR WELDING STRUCTURE TYPE BOGIE

초록

Background Bogie is the connection device between carbody and wheel in railway vehicles. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consists of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. When the bogie is designed, finite element method, static load test, fatigue test, running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment.Methods For the understanding of the crack cause, following tests were done 1) Finite Element Method using the NISA 2) Static load test for bogie frame 3) Investigating for commercial service cars 4) Tests in commercial lines Some of strain gauge was installed in weak points of the bogie frame for test cars. Strains were measured in each point Also several vibration accelerators were installed in the end of the bogie frame for grasp of the aspects of the vibration. Conclusions The best effects on the life of bogie frame were vibration on running not load on braking. Cracks were happened to concentration of stress due to welding badness, manufacture fault"