Research On Barking Performance Of Tank Vehicles Based On Dynamic Characteristics Analysis Of Longitudinal Liquid Impact

As the main means of transportation of dangerous goods by road,liquid tanker accounts for an important proportion in the dangerous goods transportation market.However,due to the fluidity and danger of the goods transported by liquid tanker,once the liquid tanker cannot brake and stop in time,the consequences of collision with other vehicles are more serious than those loaded with ordinary goods.Under the influence of external force,that is,when the speed of the liquid tank car changes,compared with solid goods,the liquid goods in the tank will produce relative movement compared with the car body,and the liquid goods will produce external force on the car body,which will make the speed change process of the liquid tank car unstable.Therefore,it is necessary to study the longitudinal dynamic characteristics of the liquid tank car and analyze the braking performance of the liquid tank car.Based on the dynamic characteristics of the liquid impact in the tank,this paper constructs the longitudinal impact dynamic model of the liquid in the tank,couples the longitudinal dynamic model of the liquid in the tank with the whole vehicle dynamic model,and establishes the whole vehicle dynamic model of the liquid tank car.Finally,the braking performance of the vehicle loaded with ordinary goods and the liquid tank car is compared through simulation calculation and analysis.The main research work and conclusions of this paper are as follows:（1）Analysis of dynamic characteristics of liquid impact in non fully loaded tank.Firstly,the influencing factors of liquid sloshing are analyzed,and the simulation setting of liquid impact in the tank is determined by FLUENT software.Finally,the longitudinal impact force and liquid center of mass trajectory of liquid impact under different liquid filling ratio and longitudinal external excitation are obtained by fluent simulation.（2）Analysis of liquid impact characteristics in tank.Analyze the fluent simulation results,analyze the characteristics of the simulated liquid longitudinal impact force and liquid center of mass displacement,obtain the relationship between the maximum longitudinal impact force of the liquid in the tank,the longitudinal stable impact force and the external excitation and liquid filling ratio under different external excitation and different liquid filling ratio,and obtain the natural frequency and damping of the impact force.The displacement of liquid centroid is analyzed,and the trajectory characteristics of liquid centroid are obtained.Based on the analysis of liquid impact characteristics,it lays a foundation for the construction of liquid dynamic model in tank.（3）Construction of liquid dynamics model in tank.Combined with the analysis of the impact characteristics of liquid in the tank and the trajectory characteristics of liquid center of mass,the quasi-static model of liquid in the tank is constructed based on the maximum instantaneous point of liquid longitudinal impact,and the spring mass damping model of liquid longitudinal impact in the tank is constructed based on the characteristics of liquid sloshing.（4）Research on braking performance of liquid tank vehicle based on liquid impact dynamics model.The fluid dynamics model is coupled with the vehicle body to establish the whole vehicle dynamics model of automobile tank car.Using MATLAB to simulate and calculate the whole vehicle dynamics model of automobile tank car,the change curve of vehicle braking deceleration under the influence of liquid shaking is obtained,the main factors affecting vehicle braking energy are determined,and the methods to improve the braking performance of automobile tank car are put forward.