The Road Particle Effect on Squeal Noise of Disc Braking System

This experimental work was carried out to examine the effect of road particle on squeal noise exerted at different load and sliding speed. The test was performed under dry sliding condition by utilizing brake test rig and commercial brake pad and discs. Squeal measurement was taken based on frequency, sound pressure level (SPL) value, vibration and brake torque measurement. The output signal from microphone and accelerometer was processed by Fast Fourier Transform analyzer to synchronize value SPL and vibration in the power spectrum graph. Simultaneous increase at the same value of frequency and SPL values showed the squeal occurrence for value above 70dBa and 1000Hz respectively. Result for test with road particle showed number of squeal tends to increase compared to test without road particle. SPL also showed high pitch of noise on squeal with road particle presence. Brake torque significantly increased with increasing brake line pressure and exaggerated with road particle. Higher brake torque resulted in higher coefficient of friction and showed high squeal generation.