An Experimental Investigation of Brake Rotor DTV under Laboratory Conditions – Part 2

This study continues work from SAE Technical Paper 2008-01-2543 [1] that demonstrated a laboratory technique for comparing brake hardware designs and evaluating the propensity for brakes-off DTV generation. The previous study compared two brake designs, including the original brake hardware (Design-A) that experienced rapid DTV growth and a later brake iteration (Design-B) which was introduced as a brake shudder fix. Measurements of both brake designs identified different piston retraction and slide loads whilst a friction material change was also noted, however no attempt was made to quantify the effect of these design changes.

The current study has been expanded to re-evaluate the same brake hardware and identify the contribution of each design change to DTV generation. The primary focus of this investigation was to analyse test samples that rapidly developed DTV as these failures cause warranty issues.

56 test results concluded that slide load was not a significant contributor to DTV generation. Further analysis applying a chi-square test established a p-value of 0.03 for friction material and a p-value of 0.002 for retraction.