Effect of Pad/Caliper Stiffness, Pad Thickness, and Pad Length on Thermoelastic Instability in Disk Brakes

Thermoelastic instability (TEI) results in uneven heating of the rotor and the development of hot spots in automotive disk brake systems. The hot spots cause rotor distortion and thickness variation which can cause torque variation resulting in brake roughness or low frequency noise. Lee and Barber (1993, ASME J. Tribol., 115, pp. 607–614) developed an analytical model to predict the critical speed above which TEI would occur. This paper describes enhancements to the model to include the effects of caliper/pad stiffness, the pad friction material thickness, and the pad length. The effects of these changes on the predicted speed are calculated and compared to the original model. [S0742-4787(00)01402-8]