Study On The Fatigue Stress Of The Key Components Of K6 Type Bogie

Four pieces of work related to the fatigue stressing analysis of the key components of K6 type bogie of railway vehicles.(1) Constructed principle of the bogie is first introduced. And a computer database with 32 basic components and an assemble technique for the bogie were developed.(2) A series of online measurements were carried out for the wheel-rail contact forces and the local deformation histories at the critical sections of bolster and side frames of the bogie. And then, two methods, i.e. a conventional method with the material monotonic Young's modulus (E) to multiply the deformation and a new method with E to multiply the static phase and with the material cyclic constitution to solve the dynamic phase of the total deformations, were subsequently applied to convert the deformations into fatigue stress. The Miner linear rule and the random cyclic constitutions were further employed to get equivalent fatigue stress amplitudes. The results show that the conventional method gives a non-conservative prediction.(3) An integrated dynamics and finite element simulation was applied to calculate the wheel-rail contact forces and the equivalent fatigue stress amplitudes at the critical sections. The results reveal that this simulation holds a significant difference to the online measurements. Additionally, the possibility is verified that the measured sections without holding the section with maximum fatigue stress amplitude.(4) An improved integrated dynamics and finite element simulation was subsequently employed to solve the equivalent fatigue stress amplitudes after a series of efforts to modify the parameters of vehicle dynamic model aiming to approach the measured wheel-rail contact forces. The results exhibit that this improved simulation is a fine technique to get correct perditions of the equivalent fatigue stress amplitudes and the section with maximum fatigue stress amplitude.