Simulation Analysis And Ride Comfort Research Of Torsion Bar Independent Suspension Of An Off-road Vehicle

As the transmission device of various forces and moments between tire and body,suspension has a great influence on the vehicle’s sports performance and riding comfort.In the torsion bar type double wishbone independent suspension,the upper wishbone and the lower wishbone are very important components,and their stress condition is bad.If the suspension components break in the process of vehicle driving,it will cause serious accidents.Therefore,in the process of vehicle suspension design,it is of great research value to analyze the suspension and ensure the performance requirements of the suspension.The research topic of this paper comes from a new generation off-road vehicle development project of an automobile company.The main research work takes the torsion bar double wishbone independent suspension of off-road vehicle as the research object,and analyzes the kinematics performance,key parts strength and ride comfort of the suspension.Firstly,according to the spatial motion characteristics of the torsion bar double wishbone independent suspension,the kinematics analysis of the suspension is carried out,and the coordinate formulas of the key points are derived by using the coordinate transformation principle,and the mathematical model of the suspension is established.Then the virtual prototype model of suspension is established by using ADAMS/Car software,and the kinematics simulation of suspension model is carried out.Four wheel alignment parameters,including camber angle,kingpin inclination angle,kingpin caster angle and toe in angle,are analyzed according to relevant vehicle design standards.The sensitivity of suspension hard point to wheel alignment parameters is analyzed by ADAMS/Insigh,and the design variables are determined to optimize the alignment parameters.Secondly,the tire forces of three typical working conditions,obstacle crossing,steering and braking,are calculated.According to the optimized suspension,the static load analysis is carried out by using ADAMS/Car,and the stress conditions of the key positions of the upper and lower wishbone are obtained.Then,the finite element model of the wishbone is established by Hyper Mesh,and the constraints and loads are added.According to different working conditions,the strength of the suspension wishbone is analyzed and checked.Finally,build the vehicle model,including suspension model,tire model,body model,steering system model,power system model and so on.In MATLAB,the B-level,C-level and d-level pavement spectrum is established by using the harmonic superposition method,and the ride comfort evaluation program is compiled based on the ride comfort evaluation index.Through the ADAMS/Car ride module,the ride comfort of the whole vehicle on different roads is simulated at the speed of 30km/h and 50km/h respectively,and the ride comfort of the offroad vehicle is evaluated.Through the analysis and optimization of the performance of the suspension of the offroad vehicle,the results show that the motion performance of the suspension meets the design requirements,the upper and lower cross arms of the suspension meet the strength requirements,and the vehicle ride comfort is good.The research provides a theoretical basis for the design and improvement of suspension,and has a certain practical value.