Random Vibration Characteristic And Dynamical Stress Analysis On Flexible Carbody

The railway plays an important role in the national economy. The development of railway promotes the national economy. Currently, the high speed vehicle is the development direction of the railway.The high speeding and heavy truck bring the railway section well economic and social efficiency, and make us face a series of new problem, such as the vibration and noise problems of the carbody are more and more obvious. It concerns about the train's safety and riding comfort. Additionally, the speeding up of the railway puts forward higher requests to the carbody light weighting, but the light weighting will make the vehicle dynamic state descend. The high speed also makes the carbody's vibration frequency range widened through bogies. That is the reason of carbody's elastic vibration. Subsequently, it definitely influences the train's safety and riding comfort.The parts'gravity center and mass were gained by building up the parts'FE-model, Modal analysis and sub-structure analysis were performed by utilizing ANSYS. The article included the multi-body system simulation and the finite element analysis. A vehicle system multi-rigid-body dynamic model and a vehicle system rigid-elastic coupling dynamic model were established by utilizing the multi-body system dynamic software SIMPACK and the finite element analysis software ANSYS. The two models'dynamical characteristics under the random excitation were calculated and compared. The quasi-static stress analysis was used to obtain the dynamic stress, and the detail method of structural quasi-static stress analysis was that the stress influence coefficients (SIC) were calculated with ANSYS, and they were multiplied with the load histories which were calculated by SIMPACK to obtain the total dynamic stress of carbody under certain load case.The paper was calculated by compromising the multi-body system simulation and finite element analysis, and the conclusions are as follows: The flexible carbody has a strong influence on vertical vibration, but it doesn't influent horizontal vibration. The mean square root of dynamic stress which was calculated under vertical and horizonal excitation is small, so the longitudinal excitation should not be neglected in the calculation of dynamic stress.