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A Dynamometer Investigation of Thermal Judder
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English
Abstract
Thermal judder occurs when differential thermal expansion is experienced around the rotor during a brake application. A temporary circumferential disc thickness variation (DTV) is created which can lead to brake torque variation. The cause of the uneven heating of the rotor can be an imperfection; often a permanent DTV caused by periods of off-brakes contact between pad and disc. Using a dynamometer test combining dynamic disc thickness measurement and pyrometric techniques the evolution of thermal DTV may be studied. It can be demonstrated that increasing thermal DTV is accompanied by increasing brake torque variation. Hot spot formation is also evident but this is shown not be the primary cause of brake torque variation.
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Authors
Citation
Little, E., Kao, T., Ferdani, P., and Hodges, T., "A Dynamometer Investigation of Thermal Judder," SAE Technical Paper 982252, 1998, https://doi.org/10.4271/982252.Also In
References
- DE VRIES, A WAGNER, M “The Brake Judder Phenomenon” SAE 920554 1992
- HAIGH, MJ SMALES H ABE, A “Vehicle Judder Under Dynamic Braking Caused by Disc Thickness Variation” Proc. ImechE Conference on Braking of Road Vehicles 1993
- INOUE, H “Analysis of Brake Judder Caused by Thermal Deformation of Brake Disc Rotors” FISITA 1986
- STRINGHAM, W JANK, P PFEIFER, J WANG, A “Brake Roughness - Disc Brake Torque Variation, Rotor Distortion and Vehicle Response” SAE Paper 930803 1993
- ANDERSON, AE KNAPP, RA “Hot Spotting in Automotive Friction Systems” Wear 135 319 1990
- KAO, TK RICHMOND, JW DOUARRE, A “Thermo-Mechanical Instability in Braking and Brake Disc Thermal Judder: An Experimental and Finite Element Study” Proc. 2 nd International Seminar on Automotive Braking 231 1998
- WOODWARD, A HODGES, T MOORE, MW “Advanced Measurement Systems for Routine Assessment of Brake Performance” Proc. ImechE Conference on Braking of Road Vehicles 1993
- FERDANI, P WILLIAMS, RS LITTLE, EJ “Current Research in Friction Materials” ImechE 1997
- KREITLOW, W SCHRÖDTER MATTHÄI, H “Vibration and “Hum” of Disc Brakes Under Load” SAE Paper 930803 1986