Wei-Yu Lu
The Journal of Mechanical Science and Technology, vol. 22, no. 11, pp.2107-2121, 2008

Abstract : Most high-rise buildings constructed of steel or steel reinforced concrete have to install various vital equipments. Among these equipments machinery noise is especially annoying for accommodation close to them. In attempting to control the machine-induced structure-borne noise and vibration, the methodology by employing mobility functions to identify the dominant frequency band of vibrational power flow transmission and to assess the isolation effectiveness of isolators is established. The proposed method of diagnosis procedure is applied to the structure-borne vibration power flow transmission for a steel construction parking tower. After proper check and replacement of the isolators of the power unit platform of the mechanical parking tower, the improvement results in a substantial structure-borne noise reduction of 16 dB(NC). The unique parts of the paper include the establishment of the relation of mobility functions with respect to four-pole parameters for a coupled machine/mount/foundation system. Also expressions to represent the vibrational input power, the output power and the transmitted power in relation to mobility functions are clarified.

Keyword : Structure-borne noise; Vibrational power flow; Resilient mount; Multi-path sound transfer; Diagnosis and identification