| With the rapid development of the national economy, flexible pavement has become the main road of the highway and urban road in China. Violent vibration of the vehicle in the process of driving process will be caused by pavement ups and downs, thereby reducing the civilian vehicle comfort and service life and impacting the travel speed and firing accuracy of armored vehicles. In order to realize active vibration control in the process of vehicle driving, we need to adjust parameters of vehicle system according the dynamic stiffness of the flexible pavement, so it has important theoretical value and practical significance to study the dynamic stiffness of flexible pavement under dynamic load.This paper establishes layered viscoelastic mechanical model of flexible pavement structure under the action of vehicle dynamic load, the multibody system transfer matrix method is used to derive transfer matrix, transfer equation of each element and total transfer matrix, transfer equation of the structure. At the same time, the calculation of the displacement and dynamic stiffness of flexible pavement is realized by using MATLAB programming, and the calculation results are compared with the calculation results of the finite element software ABAQUS. The main results obtained in this paper are as follows:(1) The dynamic stiffness of the flexible pavement under the dynamic load is increasing with the increasing of the speed of the vehicle speed.(2) The dynamic stiffness of the flexible pavement under the dynamic load decreases with the increasing vehicle loading, and the change amplitude is very large, and it has a nonlinear relationship with the increase of vehicle load.(3)The pavement thickness of flexible pavement has a certain influence on the dynamic stiffness of flexible pavement under dynamic load. There is a critical value of the road surface thickness of flexible pavement, when the thickness of the surface layer is less than the critical value, the dynamic stiffness decreases with the increase of the thickness of the surface layer, and when the thickness of the surface layer is more than the critical value, the dynamic stiffness remains the same.(4) The dynamic stiffness of the flexible pavement under the dynamic load increases with the increase of the structural layer material modulus, and the subgrade modulus on road dynamic stiffness is the most significant. |
