Study On The Distribution Of Extreme Of Vehicle Random Response Based On Subset Simulation

In the vehicle-bridge coupling system,the response is random because the track irregularity as the excitation source is random.Moreover,due to the change of vehicle position on the bridge,the vehicle-bridge coupling system is a time-varying system.The vehicle-bridge coupling system is a nonlinear system due to various factors such as wheel-rail contact nonlinearity,damping nonlinearity,bridge nonlinearity and so on.Therefore,for such a complex system,how to efficiently study its random response distribution has been a difficult problem in this field.In previous studies,scholars have used random vibration theory to calculate,but due to the complexity of the system,the existing random vibration theory can not solve this problem well.In this paper,based on the existing research,the following studies are carried out from two aspects,reducing the number of samples and calculating time of single sample of direct simulation method:(1)For a complete vehicle-bridge coupling system considering wheel-rail contact,a subset simulation method is used to reduce the sample computation.And compared with the calculation results and efficiency of direct simulation;(2)For vertical vehicle-bridge coupling systems that do not take into account wheel-rail contact,approximate models are used to reduce the calculation time of individual samples and to combine the subset simulation method.Finally,the results are compared with the calculation efficiency of the direct simulation method.The results show that the sample usage can be reduced to 1/6～1/7 of the direct simulation using the subset simulation method,and the obtained extreme value distribution is in good agreement with the results obtained by the direct simulation method.Combined with the approximate model,the calculation speed is further improved.Therefore,it is feasible to apply the subset simulation method and approximate model to the calculation of the extreme value distribution of the random response of the vehicle-bridge coupling vibration system,which provides a new idea for the study of the random response of the vehicle-bridge coupling vibration system.