Test And Simulation Analysis Of Dynamic Characteristics Of Automotive Drive Shaft System

In automotive transmission systems,the drive shaft system is used between the differential or end reduction gears and the wheels to transmit motion and power.During the driving process of the vehicle,due to the structural characteristics and the gap characteristics of the drive shaft system,the transmission of motion and power is not in a static equilibrium state and the dynamic force is generated in the lateral direction of the vehicle.This series of dynamic characteristics will affect ride comfort and is an important indicator of the performance of the drive shaft related to NVH.In this thesis,the dynamic characteristics of a tripod-ball type constant velocity joint drive shaft is taken as the research object,the multi-body dynamics model of the drive shaft is established based on bench tests.The main work of this paper is as follows:Firstly,based on the TS-GIM drive shaft function test bench,axial derivation bench tests of the drive shaft are designed to explore the influence of the joint angle,the load torque,the rotational speed and the tulip radius on the generated axial force.The friction coefficient of the friction pair between the ball ring and the chute is obtained by linear fitting of the RANSAC algorithm.Secondly,the multi-body dynamics model of the drive shaft is established based on the bench test.The normal contact model uses a nonlinear spring damping model,and the tangential contact model uses an improved Coulomb friction model.For the dynamic friction coefficient in the tangential model,the fitting value of the friction coefficient between the ball ring and the chute friction obtained by the bench test is used.For the parameters of the normal contact model,an orthogonal experiment is designed to investigate the influence of various factors on the output of the model,polynomial response surface models were established to determine parameters of the normal contact model.Finally,based on the calculation results of the multi-body dynamics model of the drive shaft,the kinematics of the drive shaft is studied:the trajectory of the center of the spider of the tripod-constant velocity joint on the moving end and the motion law of the center of the ball ring.The simulation experiments of multi-body dynamics model are conducted,combined with its motion characteristics,analyzes the variation law,influencing factors and related performance improvement measures of axial derivative force,plunge resistance force,quasi-isokineticity of drive shaft and transmission efficiencyIn this thesis,a modeling method for the dynamics model of the drive shaft system based on the multi-body dynamics model of the bench test is proposed,the influencing factors and related performance improvement measures of the dynamic characteristics of the drive shaft system are analyzed,which is of great significance for predicting the performance of the drive shaft system and guiding its forward design.