The Dynamic Characteristic And Dynamic Parameters Optimization Of High-Speed Trains Under Aerodynamic Loads

With the increase of the running speed of high-speed train, the influence of air flow on trains is more intensified, which leads to the dynamic response more deriatoriate. The airflow around the train is more obvious, aerodynamic forces on the facility next to the tracks induced by the train wind are exacerbated, which intensify the dynamic response of the facility. Therefore, it is very necessary to study and optimize the dynamic characteristics of trains under aerodynamic loads.Based on aerodynamics and vehicle dynamics, with using the vehicle dynamic software SIMPACK and ADAMS, computional fluid dynamics software FLUENT, and multi-objective optimization software ISIGHT, the dynamic characteristics and the multi-objective optimization of dynamic parameters of the trains under aerodynamic loads are studied. The main works include:1. Dynamic characteristics of the train are studied when the train passes by the noise barrier. Based on aerodynamics and transient dynamics, the pressure distribution characteristics of the measuring points and transient response characteristics of noise barrier and the trains are simulated. The results show that the maximum deformation occurs in the middle region of bottom arc barrier, and the maximum stress occurs in the connected region of the support and truss. At the instant of the trains entering and leaving the noise barrier, the aerodynamics and the dynamic characteristics of trains change suddenly.2. The dynamic characteristics of trains passing by bridges of different height under crosswind are studied. By building aerodynamic model of trains cross, the influence of bridge height on passing performance of high-speed trains under cross-wind is studied. The results show that when the height of bridge is less than15m, with the increase of the height of bridges, the maximum amplitude of the train aerodynamic load and the safety indexes are reduced., while the height of bridge is in the range of15m and30m, with the increase of the height of bridges, the aerodynamics and dynamics performance of trains remain unchanged.3. The dynamic characteristics of rigid-flexible coupling trains considering elastic carbody are studied. Based on the substructure method, the elastic carbody is loaded onto the software SIMPACK, the dynamic response characteristics between the rigid-flexible coupled model and the multi-rigid-body of the model are compared. The results show that the displacement of elastic carbody under aerodynamic load is slightly larger than that of rigid body in the location of center mass, and the vibration accelerations of elastic carbody are higher than those of rigid body.4. The multi-objective optimization of dynamic parameters of trains under aerodynamic loads. Based on the co-simulation of ADAMS and ISIGHT, safety indexes are optimized by using multi-objective genetic arithmetic when the train is running in cross wind or the trains pass each other. The Pareto optimal solution of the frontier is obtained, and the optimal solution sets of different dynamic parameters are vertified.