Prediction of Hot Spots by Correlating Finite Element Analysis and Measurement for an Automotive Disk Brake

Generally, the thermoelastic instability (TEI) theory, which considers disk critical speed as one of the most significant factors, is used for investigating judder vibration. However, since the solution of judder problems by the TEI theory requires numerous assumptions, the experimental and the TEI results do not agree well. In addition, during experiments the critical speed varies with the pressure between the disk and the pads. In this study, for a TEI analysis, critical speeds of the disk brakes are obtained by using Hotspotter ^TM , and the experimental critical speeds and the number of hot spots are obtained with a chassis dynamometer and IR camera. Pressure distributions of the brake pad are calculated by a finite element analysis (FEA). Regression analysis and linear interpolation are performed to find the correlation between the experimental results for pressure of the master cylinder, the pad arc length, and the two disk specimens. The results show that the pressure interpolation results of the experimental equation have significant effects on the TEI analysis results.