Acoustic Characterization of Pneumatic Percussion Tools

摘要

Pneumatic powered percussion tools are extensively used in construction industry. They are oneof the noisiest machines in the construction industry generating noise levels above 110 dBAwhich are well beyond the permissible exposure limit (PEL) of 85 dBA. This work presents acomprehensive methodology for the acoustic characterization and noise source identification ofthese percussion tools. Noise tests were carried out on different percussion tools ranging fromsmall chipping hammers to rock drills from two major construction equipment manufacturingcompanies. A spherical array of microphones was used to obtain an accurate estimate of theoverall sound power levels and the directivity. The overall sound power radiation was found tobe in the range of 110-115dBA. An advanced 63 microphone phased array was used tosuccessfully locate and identify the major sources of noise from this tool. In addition to the noisedata, modal hammer test and finite element models were used to aid in the identification of thenoise sources. The outcome of the tests is illustrated in detail in the paper. Experimental andnumerical results are presented for the case of a chipping hammer tested in an anechoic room.