Analysis And Optimization Of A Torsion Beam Suspension Kinematics And Dynamics

The suspension is the general term of the connecting device between thevehicle’s frameand axle or wheels. In the process of the car, the wheel alignment parameters (the toe angle,the camber angel) and the wheel track will be changed. The kinematic characteristics ofsuspension plays a vital role in full-vehicle vehicle handling&stability and ridecomfort.Suspension kinematics and dynamics analysis, as an important aspect of suspensiondesign, is attached more and more attention..Because of the advantage of the rear twist beamsuspension,it is widely used inA-class cars, therefore, Therefore, research on the torsion beamsuspension has attracted wide attention.Associated with the torsion beam design and development,applied the related data of apassenger car rear suspension, this dissertation focuses on the torsion beam suspensionstructure characreristics and its influence on the suspension kinematics.First of all, torsion beam structure(including the direetion and position of the beam) has adecisive effect on the motion characteristics of the torsion beam suspension. From thetheoretical point of view, the shear center of torsion beam was obtained according to theprinciple of mechanics of materials, Based on the spatial coordinate transformation matrixand analytic geometry of space, the mathematical model of torsion beam suspension wasestablished under roll case. The mathematical model was verified by test data and thesimulation on the corresponding model set up with ADAMS. furthermore, by studying theinfluence of the position of the cross section, the orientation of the cross section onsuspension K characteristics, the relationship between these factors and suspension Kcharacteristics were given.Secondly, The beam structure is an important factor affecting the suspension torsionstiffness.therefore, Suspension roll mechanics model was set up, using the initial parametermethod of structural mechanics, the analytical solution of torsional stiffness of torsion beamwith stabilizer bar is deduced, on the basis of which the mathematical model of its equivalentroll stiffness at the wheels is established, The mathematical model is verified by thesimulation on the corresponding model set up with ABAQUS software.Again, A rigid-flexible coupling dynamic model of the torsion beam suspension wasestablished using ADAMS/CAR software and the opposite-wheel simulation test wasperformed, the variation characterists of wheel alignment parameters, lateral slip, roll centerheight and roll stiffness are gained, which compared with the MATLAB simulation resultsand test data, as s result,both two model are mutually verified.Finally, Combined GA algorithm with the mathematical model, an optimization is conducted to the variation of toe angle,tire side slip and static roll center height duringsuspension bouncing,all the non-dominated solution can be worked out at one time.Thesuitable suspension roll kinematics characteristics can be chosed from the obtained Paretosolution according to design requirements,which can be used to direct design of torsion beamsuspension, as a result, greatly improve the torsion beam suspension design efficiency.