JOHN W. EVERT | Mechanical Engineering Technology
Results
Initial testing of static mass as well as moment of inertia produced a 23.8% decrease in the moment of inertia and 1.55lbs mass reduction.
Location on vehicle is of paramount concern. Given a 75%/25% front/rear brake bias, the front is subjected to 123kW of kinetic energy whereas the rear is 41kW. For On-Vehicle testing, rotors were mounted to the front axle.
After 7-second cool down period, temperature entering the braking zone was 163°C for the vented iron rotor and 99°C for the fabricated rotor respectively, ΔT = 64°C .
Testing was necessary to retrieve a convection coefficient in order to calculate remaining thermal energy for a new ΔT in the next braking event.
Failure of fabricated rotors occurred on Lap 11 of Session 3 (74 total laps) due to warping (495°C peak temp).
Driver was instructed to drive more aggressively and brake deeper into deceleration zones since fabricated rotors were performing satisfactorily in sessions 1 and 2.
