折版D88形状に制振鋼板を適用した場合の騒音低減効果

抄録

The noise reduction effect of the damping steel sheets has been studied by a single ball impact test and an artificial shower test for building roofs. The shape of test specimens were flat sheet and V-Deck D88. This study has resulted in the following 4 points.
(1) The noise reduction effect of damping steel steet was very large (about 6 dB) in the case of V-Deck D88, and that was not so large (about 2 dB) in the case of flat sheet.
(2) The noise reduction effect of damping steel sheets, as same as the logarithmic decrement, increases as the frequency hightens.
(3) The difference of the noise reduction effect between flat sheet and V-Deck D88 can be explained by the frequency dependency of sound pressure level, i.e. in the case of V-Deck D88, sound pressure level is large at the higher frequency region where the noise reduction effect is large, but in the case of flat sheet it is not so large at this region.
(4) The effect of nozzle diameter in the artificial shower test is not so large on the noise reduction effect of damping steel sheets.