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Abstract
The hysteresis, stick-slip, and rotational speed-dependent characteristics in a basic dual mass flywheel are obtained from a static and a dynamic experiments. Based on the experimental results, a nonlinear model of the transferred torque in this dual mass flywheel is developed, with the overlying form of nonlinear elastic torque and frictional torque. The nonlinearities of stiffness are investigated, deriving a nonlinear model to describe the rotational speed-dependent stiffness. In addition, Bouc-Wen model is used to model the hysteretic frictional torque. Thus, the nonlinear 2-degree-of-freedom system of this dual mass flywheel is set up. Then, the Levenberg-Marquardt method is adopted for the parameter estimation of the frictional torque. Finally, taking the nonlinear stiffness in this model into account, the parameters of Bouc- Wen model are estimated based on the dynamic test data.
Keywords
Hysteresis, dual mass flywheel, rotational speed dependent, nonlinear modeling, parameter estimation
Date received: 2 December 2014; accepted: 13 March 2015
Academic Editor: Ioan Pop
(ProQuest: ... denotes formulae omitted.)
Introduction
The reciprocating internal combustion engines are used in almost every automotive vehicle recently. The oscillated gas-pressure torque caused by the periodic combustion processes and the unbalanced inertia torque excites the driveline, which generates the torsional vibrations. Torsional vibrations in automotive vehicle bring a number of comfort problems, namely, "rattle noise." Torsional vibrations transmitted from engines can be mechanically isolated when a dual mass flywheel (DMF) is fitted between the engine and transmission.1
A basic DMF consists of two separated flywheels connected by a spring-damping damper, as shown in Figure 1. The long-travel arc springs are compressed or decompressed along the shell, transferring the torque from engine. To reduce wear, lubricating grease is filled in spring channel, generating damping as well. A applicable model of DMF is significant to predict the dynamic behaviors of power train. Walter et al.2-4 and Lei et al.5 have simplified a DMF as a 2-degree-of-freedom system, which is a linear mass-spring-damper model. Using this model, the torsional vibration characteristics of the power train fitted with the DMF are predicted. However, Schnurr6 has observed nonlinear dynamical phenomenon as early as 1990. A dynamic test for a super-long-travel DMF was conducted, and frictional hysteresis as well as the rotational speed-dependent characteristic was found. Before long-travel DMF, Albers7 established a...