Chassis Design And Performance Simulation Of6×6Off-road Vehicles

With the development of the logistics industry in recent years, and the level of the road, the truck is developing towards multiaxial and load. As a multi-axis vehicle, the body relatively long, and mostly two-axis or more than two-axis steering, therefore, handling stability of multi-axis vehicle is an important research topic.Known the6×6off-road vehicles in the design objectives, according to driving force requirements of the vehicle, using vehicle systems dynamics relevant theories, matched the drive system. According to Automotive Design Manual requirements, completed of the chassis design. Use the finite element software for modal analysis and static analysis for the frame. Based on the vehicle dynamic simulation calculation, the chassis design meet performance requirements, maximum speed above65km/h, the maximum gradeability greater than60%. Meanwhile, the finite element analysis results show that the frame meets the vehicle strength and stiffness requirements，even in the harshest conditions of the mid-wheel unconnected, the safety factor is still greater than2, natural frequency of the frame avoid the engine idling time and Road Surface Roughness incentives it, indicating the frame design qualified.According to the Mechanical Analysis of the6×6off-road vehicle1/2model, derived and summarized the two degrees of freedom steering model for three-axle vehicle. Put front wheel steering angle as an input, yaw rate and sideslip angle as outputs, using the Laplace transform, derived the transfer function expressions. On the basis of the two degrees of freedom steering model for three-axle vehicle, consider the impact of the roll and pitch motion of the sprung mass on vehicle steering characteristics, And the complex conditions of the tire lateral force nonlinear factors, well as nonlinear factors of the tire lateral force at complex working conditions, Established a five degrees of freedom steering model for three-axle vehicle. Analyzed the cornering characteristics of6×6off-road vehicle，by using Matlab/Simulink, got the steady state response and transient response of cornering characteristics, while the input is step signal of the front wheel angle. The results showed that6×6off-road vehicle has some under steering tendency. In the same conditions of the simulation experiments, nonlinear five degrees of freedom model has longer response time, larger yaw rate and smaller sideslip angle.By using ADAMS/car established the vehicle model, evaluated the handling and stability of the6×6off-road vehicle. Simulation experiment of Transient and steady-state response test rotation, etc. According to the national standard for heavy trucks, handling and stability composite score of the6×6off-road vehicle was got. Provide theoretical support for the design and improvement.