Nonlinear Dynamic Analysis And Applications Of Monofilar Centrifugal Pendulum Vibration Absorber

Compared with the traditional torsional vibration absorber,centrifugal pendulum vibration absorber?CPVA?can significantly reduce torsional vibration at its tuning order during the whole speed range and improve the NVH performance of vehicle drivetrain much more effectively.However,due to its strong nonlinearity,the CPVA may be instabilities,such as jump,bifurcation and so on,which can lead to strengthen torsional vibration.In order to promote the application of CPVA in drivetrain properly,the nonlinear characteristics of CPVA is investigated comprehensively by theoretical analysis and experimental validation.The main contents can be summarized as follows:1)The nonlinear dynamic model of monofilar CPVA is established,and its tuning characteristic is analyzed.A torsional vibration test rig is set up.Then the established model is verified by the amplitude-frequency response curve obtained by the measurements and calculations.By the harmonic balance method,the steady state responses are calculated and the characteristic of the feature revolution for the CPVA is analyzed.And the simplified model,retaining the basic nonlinear characteristics,is established by force analysis.2)The evaluation indexes of the whole performance in any frequency range is proposed.The evaluation indexes and the nonlinear dynamic model of monofilar CPVA are used for analyzing the performances of the vibration isolation which are the excitation amplitude and order,the damping,inertia and stiffness of the main system,and the number of the CPVAs.Furthermore,the accuracy of the simplified model of monofilar CPVA is also analyzed.And the key points of design for CPVA are given.3)In order to investigate the influence of CPVA on the NVH performance of the drivetrain,the lumped parameters model of drivetrain is established.And its steady state response is used for obtaining the equivalent single degree of freedom?SDOF?model of the drivetrain.By combining the equivalent SDOF model,the simplified model of CPVA and the key points of design for CPVA,the parameters of the monofilar CPVA are determined.It is concluded that the feature revolution is equal to the engine revolution at the idle.The design effectiveness of CPVA for the drivetrain is verified by comparing the torsional vibration response of the drivetrain at the idle and the whole open throttle of 1^stgear.The research in this paper provides an effective method to guide the design of CPVA.It is of great significance to the application of CPVA in the vehicle transmission system.