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Comparison of Pad Stiffness under Static Pressure and Vibration with Small Amplitude
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 17, 2012 by SAE International in United States
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It is necessary to consider both pad stiffness in static and dynamic situations to develop brake pads that create effective braking and squeal less. Brake pads that have a high degree of static stiffness generally respond well when braking. A past study clarified that stiffness when vibration is added to a pad differs from static stiffness. This pad stiffness in dynamic situations depends on braking pressure and it is one of the causes of squeal generation. This research clarified that pad stiffness depends on the amplitude of excitation and its frequency, which was measured by using an experimental apparatus. This apparatus gave sufficient displacement to a pad for measuring static stiffness and gave vibration with sufficient frequency and amplitude to assess the stiffness of the pad when squeal was generated. First, the static stiffness of the pad was measured by adding static pressure. Then, the dynamic stiffness of the pad was measured by adding small-amplitude and high-frequency vibration. This dynamic stiffness was more than twice that of the static stiffness. Vibration with various amplitudes and frequencies was added to a pad and pad stiffness was measured to investigate why the dynamic stiffness of the pad differed from its static stiffness. The pressure-displacement characteristics of the pad exhibited hysteresis. Thus, pad stiffness increased immediately after decompression from pressurization had started. The hysteresis of the pad decreased when the excitation amplitude decreased and excitation frequency increased. When the amplitude was sufficiently small and frequency was sufficiently high, the stiffness of the pad increased and it approached the dynamic stiffness from static stiffness. Measurements of pad stiffness represent a fundamental technology that is required to develop squeal-less pads and it is necessary to take into consideration the change in stiffness that depends on measurement conditions.
CitationOura, Y., Kurita, Y., Nishizawa, Y., and Kosaka, K., "Comparison of Pad Stiffness under Static Pressure and Vibration with Small Amplitude," SAE Technical Paper 2012-01-1818, 2012, https://doi.org/10.4271/2012-01-1818.
- Augsburg, K. Günther, H. Abendroth, H. Wernitz, B. “Comparison Between Different Investigation Methods of Quasi-Static and Dynamic Brake Pad Behaviour,” SAE Technical Paper 2003-01-3340 2003 10.4271/2003-01-3340
- Earles, S. “A Mechanism of Disc Brake Squeal,” SAE Technical Paper 770181 1977 10.4271/770181
- Millner, N. “An Analysis of Disc Brake Squeal,” SAE Technical Paper 780332 1978 10.4271/780332
- Sueoka, A. Ryu, T. Shirozu, K. Squeal of a Disk Brake of Floating Type for Cars: 1st Report, Relationship between Occurrence of Squeal and Contact Region between Rotor and Pads in Experiment Transactions of the Japan Society of Mechanical Engineers 67 658 1719 1726 2001
- Oura, Y. Kurita, Y. Matsumura, Y. Nishizawa, Y. “Influence of Distributed Stiffness in Contact Surface on Disk Brake Squeal,” SAE Technical Paper 2008-01-2584 2008 10.4271/2008-01-2584
- Kurita, Y. Matsumura, Y. Ito, A. Tamura, T. Oura, Y. “Squeal Vibration in Disk Brake” Transactions of the Japan Society of Mechanical Engineers 70 694 1609 1615 2004
- Oura, Y. Kurita, Y. Matsumura, Y. “Influence of Dynamic Stiffness in Contact Region on Disk Brake Squeal” Journal of Environment and Engineering 4 2 234 244 2009
- Oura, Y. Kurita, Y. Matsumura, Y. Tamura, T. “Surface Contact Analysis Model of Disk Brake Squeal” Journal of Environment and Engineering 4 1 222 233 2009
- Oura, Y. Kurita, Y. Matsumura, Y. Nishizawa, Y. Kosaka, K. “Influence of Brake Pad Thickness on Disk Brake Squeal” Journal of System Design and Dynamics 4 6 Special Issue on D&D2009 970 983 2010
- Kosaka, K. Nishizawa, Y. Kurita, Y. Oura, Y. “Influence of Pad Surface Texture on Disk Brake Squeal,” SAE Technical Paper 2011-01-2354 2011 10.4271/2011-01-2354