Principle And Experiment Of Variable Stiffness Damping Of Magnetorheological Torsional Damper In Power Driveline

Due to the self-manufacturing assembly error and the variability of the excitation,the power driveline will have a torsional vibration phenomenon when transmitting power,generate noise,affecting the stability of the mechanical system operation,and endanger the safety life of the system components.In order to reduce the torsional vibration of the transmission system,scholars have studied a variety of torsional vibration reduction schemes,among which the more effective measures are: installing a torsional vibration damper with low stiffness and damping links in the power driveline.However,as the power driveline develops toward high power density,higher requirements are placed on torsional vibration control.Although the current torsional vibration damper adopts a certain method to achieve the change of stiffness and damping,it can not be adaptively adjusted according to different working conditions,so the damping effect is limited,and can not meet the torsional vibration damping requirements of the power driveline.The magnetorheological actuator is developed by the magnetorheological technique,which has a wide adjustable damping range and fast response.Low power consumption and other advantages have broad application prospects in vibration control.In addition,in recent years,the change of stiffness through magnetorheological technology has attracted the attention and in-depth research of scholars,and some research progress has been made.Therefore,in view of the shortcomings of the current torsional vibration damper,a torsional vibration damper with magnetic rheological technology for adaptive adjustment of stiffness and damping is proposed.The principle of variable stiffness and damping is analyzed,and a new type of test is tested.The variable stiffness and variable damping characteristics of the torsional vibration damper are validated by the design method of the magnetorheological stiffness-damping torsional vibration damper.The work of this paper mainly has the following aspects:(1)The simplified torsion model of the power driveline is established and analyzed.The effects of stiffness and damping parameters on the natural frequency and resonance amplitude of the torsion system are studied.The principle of variable stiffness and variable damping torsional vibration is revealed.(2)A design method of magnetorheologically variable stiffness variable damping torsional vibration damper is proposed.The working principle of the magnetorheological variable stiffness variable damping torsional vibration damper is expounded.The variable stiffness and damping mechanical model is analyzed.The influence parameters of the equivalent stiffness and damping of the system are studied,and the mechanical calculation formula of the magnetorheological unit is derived.The expression expression of the torsional vibration damper output torque is further obtained.(3)According to the principle of variable stiffness and damping,the main parameters of the magnetic flow variable stiffness and damping damping torsional vibration damper are determined.The specific structural design,magnetic field theory calculation and finite element simulation analysis of the magnetorheological unit were carried out.The genetic algorithm and multi-objective optimization software were used to optimize the key structural parameters of the magnetorheological unit.At the same time,the spring was selected and calculated.(4)According to the optimized parameters,the processing assembly of the magnetorheological variable stiffness variable damping torsional vibration damper was carried out,and the test was carried out on the MTS test bench.Firstly,the purchased spring stiffness is tested and compared with the theory.Secondly,the output mechanical characteristics of the magnetorheological unit with different excitation frequency and different amplitude conditions are tested.The final variation of the magneto-rheological stiffness is damped.The variable stiffness and variable damping characteristics of the torsional vibration damper were tested.The experimental results show that the stiffness and damping characteristics can be controlled by the excitation current,which verifies the effectiveness of the magnetic flow variable stiffness and damping design method.