Research On Driving Stability Of Liquid Tank Vehicle Based On Nonlinear Equivalent Mechanical Model Of Liquid Lateral Sloshing

As the main carrier of liquid cargo transportation,liquid tank trucks occupy an important proportion in cargo transportation.Due to the particularity of cargo transported by tank trucks,the damage caused by traffic accidents in tank trucks is often more serious than other vehicles.According to statistics,tank trucks often experience bicycle rollover accidents at high-speed corners.Therefore,it is necessary to study the dynamic characteristics of the tank truck and analyze its driving stability characteristics.In this paper,the liquid sloshing dynamics of the tank is taken as the starting point,the motion of the liquid is transformed into mechanical motion,and the dynamic model of the tank truck is constructed.Finally,the lateral stability and rollover characteristics of the tank truck are analyzed by simulation.The main research work and conclusions are as follows:(1)Construct a liquid sloshing equivalent mechanical model considering damping dissipation.Taking the cylindrical tank and the elliptical cylindrical tank as the research object,the oscillation characteristics and attenuation characteristics of the liquid sloshing in the tank under the shaking condition of 0.1~0.9 and lateral excitation of 0.1g~1.0g were studied.The centroid motion trajectory and damping coefficient of the liquid sloshing are determined.Through the kinematics and mechanical analysis of the liquid centroid,an equivalent mechanical model considering the damping effect of the liquid sloshing in the cylinder and the elliptical cylinder can be constructed to convert the motion of the liquid into mechanical motion.(2)Construct a tanker dynamics model that considers the rollover characteristics.When constructing the model,the tank truck was divided into sprung,unsprung,stationary liquid and moving liquid parts and their own coordinate system and vehicle coordinate system was constructed.On this basis,the dynamic characteristics are analyzed,and the equivalent mechanical model of liquid sloshing is coupled into the vehicle model to construct a tank truck simplified dynamic model with lateral motion,yaw motion,roll motion and pendulum motion as degrees of freedom.In addition,the model also considers the influence of the cargo load on the change of the centroid position of each part,and the influence of the lateral load transfer on the tire side bias during the running of the vehicle.(3)Simulation analysis of the dynamic characteristics of the tank truck.Based on the constructed tanker dynamics model and the common truck model,the filling ratio is 0.0~1(interval is 0.1),the liquid dimensionless damping coefficient is 0~0.2(interval is 0.1),the cylinder and the two elliptical cylinder conditions(Cross section length to short axis ratio 1,1.5,2).The simulation analysis was carried out from two aspects of lateral stability and rollover characteristics of the tank truck.The analysis results show that When the liquid filling ratio is about 40%~50%,that is,when the cargo loading is about 40%~50%,the lateral stability and rollover stability of the tank truck are relatively poor;the ratio of the length of the tank body is larger,the lower the lateral stability of the tank truck,the stability of the rollover is first reduced and then improved;the dimensionless damping coefficient of the liquid has little effect on the lateral stability and rollover stability of the tank truck.