Correlating Dynamometer and Vehicle Brake Test Results: Brake Squeal

Brake noise dynamometers are fundamental engineering tools for the systematic and efficient investigations of noise. However, the data obtained from a dynamometer must correlate with the noise achievable on a corresponding vehicle to be of true value in an investigation.

The factors that can influence correlation between both vehicle and dynamometer tests are examined. In particular, correlation based on the following:

• techniques for noise data acquisition, evaluation and testing
• variations of the brake system under load and time such as aging and wear effects
• differences in the test procedure brake application parameters
• variability of individual brake system components in terms of technical release and part-to-part variation.

Problems and approaches for correlating dynamometer and vehicle brake test results are described. Test results for the correlation dynamometer - vehicle are also shown.