Optimization Design On The Suspension System Parameters Of High Speed Train Under Cross Wind

With the rapid development of high-speed railways,the running speed of high-speed trains has been significantly improved,and the problem of the safety of high-speed trains has become more and more obvious.Dynamic parametric variation of high-speed train suspension system will affect the safety of train operation,especially in crosswind conditions.Combining computational fluid dynamics and multi-body system dynamics theories,the paper analyzes the influence of dynamic parametric variation of train suspension system on the safety of train running in crosswind conditions,and constructs the optimization model of suspension system in crosswind conditions,to carry out ingle-objective optimization,multi-objective optimization and multi-objective optimization for multi-operational conditions.It mainly includes the following aspects:(1)Establish models of multi-body system dynamics for high-speed trains,and analyze the influence of dynamic parametric variation of suspension system on the running safety of train.The research shows that the vertical stiffness of the secondary air spring has a great influence on the running safety of high-speed trains.The derailment coefficient,the wheel unloading rate,the wheel rail vertical force and the wheelset lateral force are all reduced as the vertical stiffness of the secondary air spring increases.(2)Establish the optimization model of dynamic parameters of the suspension system in crosswind conditions with the derailment coefficient as the optimal target,and analyze the calculation results of different single-objective optimization algorithms,to achieve the best effect of hybrid single-objective optimization algorithm based on MIGA global exploration and DS algorithm.(3)Establish the optimization model of dynamic parameters of suspension system in crosswind,and carry out multi-objective optimization of the high-speed train with the wheelset lateral force and the wheel unloading rate as the optimization targets.The optimization results show that the derailment coefficient,wheel-rail vertical force and wheelset lateral force achieved better convergence effect after multi-objective optimization,and the value of wheel unloading decreased significantly.Comparing the Pareto weighted optimal solution with the initial data,it is found that the displacement of the car body in the horizontal and vertical directions has been effectively improved,and the wheel lateral and vertical displacements have achieved obvious optimization effects compared to the initial value,so as to allow operational safety metrics to be optimized.(4)Carry out multi-objective optimization of kinetic parameters of trains running at a ten-meter bridge under multiple running conditions.The results show that the safety of train running based on multi-objective optimization at a ten-meter bridge under multiple running conditions achieved good optimization results.After optimization,the lateral and vertical displacements of the train are reduced to different extents,so that the wheel-rail force is reduced,operational and security is optimized.