Analysis Of Dynamic Load Of Heavy Vehicle On Damaged Cement Concrete Pavement

When a vehicle encounters an uneven surface during driving,it will generate vibration,which will cause the wheel to generate additional dynamic loads on the road surface.This dynamic load is an ever-changing load that is not equivalent to a static load and will accelerate the destruction of the road surface.The increase in road surface roughness will increase the dynamic load generated by the wheels on the road surface.This coupling effect will greatly affect the road performance and life.However,with the gradual development of freeway traffic network and the gradual increase of heavy-load vehicles,the destruction speed of cement concrete pavement has increased dramatically,resulting in the failure of the wrong types of benches,pits,making the actual service life of cement concrete pavement far lower than design life.In addition,when the dynamic load is too large,it will affect vehicle safety and handling stability.Therefore,combining the vehicle and the road surface to study and analyze the impact of vehicle dynamic load on the road surface has become one of the hot issues in the field of vehicle dynamics and road research.Based on the coupling relationship between the vehicle and the road surface,this paper takes the Futian Aumax S5 heavy-duty truck as the research object,and analyzes the dynamic load changes of the double-axle heavy-load vehicle on the damaged cement concrete pavement.The results and conclusions are summarized as follows:(1)Based on the consideration of the main damage forms of cement concrete pavement,the causes and hazards of cement concrete pavement damage are analyzed,and the main factors affecting the dynamic load of heavily loaded vehicles are determined.(2)According to the concept of road roughness,the causes of vehicle vibration and the relationship between the uneven road surface and the vehicle dynamic load are analyzed.The theoretical model of four-degree-of-freedom vibration model is determined and the expression of the dynamic load generated by different pavement excitations is deduced.The dynamic load coefficient of the vehicle is used as the evaluation index of the dynamic load.(3)According to the theory of multi-body dynamics,a heavy vehicle dynamics simulation model was established.Corresponding road surface models were established for the wrong types of benches road and pit road.Vehicle-road coupling simulation was realized by programming simulation driven files.(4)This paper analyzes the dynamic load change curves of vehicles under different dislocation heights,different pit depths,different speeds,and different load conditions,and draws the following conclusions: The bench has a significant influence on the dynamic load of the vehicle.The dynamic load of the front wheel is greater than that of the rear wheel at the same height of the wrong bench.The effect of the pit relative to the bench on the dynamic load of the wheel is smaller,and the pit is easy to make the wheel jump off the ground,which affects the safety of the vehicle.The higher the vehicle speed,the greater the dynamic load of the wheel on the damaged road surface.When the road surface is damaged seriously,the main factor influencing the dynamic load of the wheel is the unevenness of the road surface and the vehicle speed becomes a secondary factor.While on a relatively flat road,the vehicle speed has a great influence on the dynamic load of the wheel.The load has a significant influence on the dynamic load of the wheel.The larger the load,the greater the dynamic load of the wheel,but the smaller the dynamic load coefficient of the vehicle.