EXPERIMENTAL CHARACTERIZATION OF THE NOISE GENERATION MECHANISM OF PERCUSSION DRILL RODS

An experimental approach is used to characterize the vibroacoustic beh aviour oi percussion drill steel rods under real operating conditions and laboratory controlled conditions. A laboratory test fixture presen ting representative boundary conditions is used. The relative contribu tion of longitudinal and flexural vibration to the noise generation is discussed. By comparing the laboratory and the in situ measurements, it is shown that the main noise source oi percussion drill rods are th e flexural waves. However, the noise reduction potential, by reducing the bending vibration, is limited by the radiation oi axial waves.