Title: Study on clutch engagement judder during launch process for dual clutch transmissions

Authors: Jinle Zhang, Biao Ma, Manfred Zehn

Addresses: Vehicle Lab, School of Mechanical Engineering, Beijing Institute of Technology, 100081, China. ' Vehicle Lab, School of Mechanical Engineering, Beijing Institute of Technology, 100081, China. ' FG Strukturmechanik und Strukturberechnung, Institut fur Mechanik, Technische Universitat Berlin, Sekr. C8-3, Str. d. 17. Juni 135, Berlin, 10623, Germany

Abstract: Clutch engagement judder, as part of vehicle noise, vibration and harshness (NVH), is an important vehicle attribute in the design of dual clutch transmissions (DCTs). This paper presents a system analytical model for clutch engagement judder during launch for DCT vehicles. Influencing factors on clutch judder, including internal factors (friction characteristic, damping, backlash) and external factors (engine torque fluctuation, applied oil pressure fluctuation), are studied analytically and numerically through system stability analysis and free vibration analysis. The results of the simulations show that clutch judder is dependent on the slope of the friction coefficient, static friction coefficient, system damping, applied oil pressure and engine torque fluctuation. Sensitivity analysis and sensitivity functions are presented to find the most sensitive elements in mass matrix and stiffness matrix to shift the undesirable system natural frequencies. The research provides a basis for refinement and optimisation of vehicle design.

Keywords: clutch judder; vehicle noise; vehicle vibration; harshness; NVH; free vibration; stability analysis; dual clutch transmission; DCT; clutch engagement; clutch design; friction; damping; backlash; engine torque; oil pressure; natural frequencies; vehicle design.

DOI: 10.1504/IJVNV.2010.036685

International Journal of Vehicle Noise and Vibration, 2010 Vol.6 No.2/3/4, pp.176 - 199

Available online: 05 Nov 2010 *

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