Dynamic Response Of Asphalt Pavement Based On Vehicle-pavement Weak Coupling Vibration

Under the repeated action of overloaded vehicles,asphalt pavement is seriously damaged.There are a variety of problems,such as slippage,cracking,rutting and pit,etc.,which will reduce the smoothness of pavement and the stability of the vehicles,seriously affect their working conditions,and accelerate the destruction of the pavement and vehicles.Vehicle vibration and tire's non-uniform load have significantly affected the mechanical behavior of pavement structure.It should be considered in the mechanics-experience pavement design method.The random vibration of vehicles is usually ignored in current codes and previous studies.It is assumed that the contact between tire and pavement is point contact or simplify to uniform contact.It failed to consider the transient change of pavement's response and vehicles' dynamic loads.The nonlinear contact between the tire and the pavement has also been negleced.There are some differences from the actual vehicle-pavement working conditions.Furthermore,it is not accurate to analyze the dynamic response of asphalt pavement with linear theory.It should be considered that the combination of nonlinear calculation method and pavement dynamics.In addition,in the past,multi-body dynamics software or MATLAB and finite element software were used for joint simulation to study vehicle-pavement working performance.Both model construction and calculation methods had great limitations.Therefore,it is very necessary to build a simulation model which is closer to the actual situation.At the same time,the mechanical behavior of vehicles and asphalt pavement contain a large number of nonlinear dynamic factors.In order to analyze the dynamics response,the time domain methods are suggested to adopted.In order to solve the problems existing in previous studies,in this article,taking ABAQUS finite element software as the platform,a multi degree of freedom vehicle model and a rubber tire finite element model are constructed,which based on the theory of multi-body dynamics and hyperelasticity.The suspension and axle were simulated by cartesian attribute and hinge attribute respectively.The tire was simulated with rubber-cord composite and its mechanical properties were verified.Based on viscoelastic theory,the conversion relationship between creep compliance and relaxation modules of asphalt mixture were deduced,and combined with references to obtain the mechanical parameters of the asphalt mixture,then the finite element model of asphalt pavement was completed.Based on the normal and tangential mechanical behaviors of tire and asphalt pavement,the surface to surface contact property was used to simulate the non-linear contact relationship between tire and asphalt pavement.The construction of the vehicle-road weak coupling vibration model was completed.In order to solve the dynamic equation of vehicle-road weakly coupled vibration,the central difference method was adopted.Compared with references and measurement experiments,the model established in this paper was verified.The results show that the vehicle-road weak coupling vibration model based on related theories has certain applicability.It can effectively simulate the working state of vehicle-road weak coupling vibration.The action form of vehicle load and axle load have great influence on the dynamic response of pavement,it can't be ignored in the study of vehicle-road weak coupling vibration.The road roughness is the main cause of vehicle-road weak coupling vibration.With the decrease of pavement grade,the effect of vehicle-road weak coupling vibration is enhanced and the dynamic response of vehicles and pavement increases nonlinearly.Since the difference of load's action form and numerical value,the response of different pavement location is greatly different.