Accession Number : ADP003710

Title :   Noise Energy Radiated from Rod-Like Structures,


Personal Author(s) : Chow,L. C. ; Cuschieri,J. M.

Report Date : 1984

Pagination or Media Count : 10

Abstract : Drill rods are highly stressed components transmitting a great deal of energy. Some of the energy input to the rod excites the rod in flexural vibration. However, the fraction of energy that goes into vibration is very small, in the order of 0.001, but this still makes rock drilling a noise hazardous operation. Typically the SPL from a drill rod is about 110 dB 1 m away from the drill. Thus the understanding of the noise generation mechanism in rock drills is important to control and the noise other than the exhaust noise if a new generation of quiet rock drills are to be designed. Using an energy accountancy concept, the noise radiated from a solid hexagonal rod and a tubular rod is investigated to obtain the parameters that influence the radiated noise. The operation of the drill is a consecutive series of impacts on the drill rod, thus the tailoring of this impact is investigated for noise control and drilling efficiency. (Author)

Descriptors :   *Structural mechanics, Machinery noise, *Noise generators, *Computations, Radiation, Rods, Drills, Energy transfer

Distribution Statement : APPROVED FOR PUBLIC RELEASE