Research On Nonlinear Torsional Vibration Of Transmission System For Special Vehicles

The performance of the transmission system has direct influence on the dynamic performance and comfort performance of the vehicle.It is helpful to study and design the shafting system by studying the torsional vibration performance of the drive system.For special vehicles,there are many non-linear factors in the shaft system,so the study of the nonlinear component model of the torsional vibration of the shaft system,such as nonlinear coupling,gears and other nonlinear transmission,has the significance in improving the accuracy of shafting research.The main work of this paper is as follows: The lumped parameter method is used to establish the concentrated mass model of diesel engine crankshaft drive system and gear transmission system.The finite element analysis and empirical formula are used to determine the moment of inertia of shaft and gear,stiffness,damping and other parameters,according to the differential method to determine the moment of each moment of excitation.The dynamic response of diesel engine is solved by using Fortran,and the error analysis is carried out to solve the problem of different components of the special vehicle.Gear meshing stiffness is an important non-linear factor in the gear transmission system.In this paper,a finite element elastic contact model of a precise involute spur gear is established.Using Abaqus finite element analysis and Ishikawa formula,the exact meshing stiffness of the gear is obtained.The meshing model of the two-degree-of-freedom gear meshing is obtained.The time-domain calculation is carried out to study the effect of gear-meshing nonlinearity on the response of the gear-drive system to time-varying stiffness,meshing error and backlash.Based on the dynamic model of crankshaft drive system of diesel engine,the coupling model of different stiffness is established and substituted in time domain,and the inherent characteristics of the system are analyzed and solved.By analyzing the nonlinear factors introduced by the different models in the excitation node,the load node and the rotation angle difference of the adjacent mass point,the torsional vibration response can provide ideas to the design of the coupling.