Authors : P. Bulski , S.D. Yu and E.D. Davidge
Abstract: Sound induced by a pair of counter-rotating grass-cutting blades in a cutting deck is studied in this study. Experimental sound pressure results are obtained using a sound pressure transducer and a data acquisition system. To explain the extraordinarily high sound pressure levels at several frequencies, a 3-dimensional finite element model for the cutting blades is developed to determine the dynamic natural frequencies including the effect of spinning. It was found that, during operations, the blades experienced several modes of resonant vibrations in the interested frequency range, which contributes to the very high noise levels at several frequencies. To reduce vibration of the cutting blades due to multi-frequency oscillatory dynamic pressure field, the effect of application of viscoelastic foil is investigated.
P. Bulski , S.D. Yu and E.D. Davidge , 2008. Investigations of Sound Induced by Grass-Cutting Blades. Journal of Engineering and Applied Sciences, 3: 290-298.