Index of content:
Volume 128, Issue 6, December 2010
- NOISE: ITS EFFECTS AND CONTROL 
Force generation characteristics of standard heavyweight impact sources used in the sound generation of building floors128(2010); http://dx.doi.org/10.1121/1.3500690View Description Hide Description
Several heavyweight impact sources have been used in applying standardized excitation forces to evaluate the noise generationcharacteristics of building floors. In this study, heavyweight sources (a bang machine and an impact ball) were filmed with a high-speed camera on the period of deformation and restitution of the impact. The generated impact force was measured, and the effects of the taken deforming shapes were investigated. Experimental modal analysis was performed to determine the natural frequencies and mode shapes of the impact sources. With respect to deforming shapes during impacts, the influence of the mode shapes was clearly demonstrated, especially for the impact ball. Using the measured modal properties, the impact force was predicted and compared to the measured excitation force. By comparing the transient variation of the excitation force and its frequency spectrum, the influence of the modal characteristics of the source on the generated impact force was investigated.