Experimental analysis on structure-borne noise in an enclosure

Abstract

This paper present the experimental analysis conducted on a structure-borne noise in a rectangular enclosure prototype made by joining of sheet aluminum metal and plywood. The study is significant as the structural noise could cause annoyance and dizziness thus by deepening the comprehension on the structure-borne noise, the noise problem could be overcome. In this study, modal analysis is carried out to seek the structure’s behavior in order to identify the characteristics of enclosure in frequency domain ranging from 1 Hz to 100 Hz. Here, numbers of modes are identified and the characteristic of mode shape is categorized. Modal experiment is used to diagnose the structural behavior while microphone is used to diagnose the sound. Spectral testing is performed on the enclosure and it is acoustically excited using shaker and as it vibrates, the vibrational and noise responses sensed by tri-axis accelerometer and microphone sensors are recorded respectively. The modal modes extracted from the experiment are validated by simulation performed using MSC NASTRAN/PATRAN software. From developed prototype, the structural behavior can be diagnosed and the mode shape can be determined. In the end of the study, the relation and major contribution of the structural and sound in the enclosure can be identified from the observation of both spectrums.