Noise Transmission Through Profiled Metal Cladding Part II: Single Skin SRI Prediction

Abstract

This paper follows from an earlier experiment investigation1 on the sound reduction of single skin, trapezoidal profiled cladding systems, paying particular attention to the pronounced “dips” in the SRI at mid frequencies. Theoretical predictions were made to confirm the previous experimental findings. Finite element analysis was used to examine the vibration modes of the profiled cladding. The boundary element method was used to investigate the radiation efficiency of the vibration modes and their excitation by acoustic plane waves. Good agreement with measured vibration data was found. An analytical method for predicting the sound reduction index of single skin profiled cladding systems is proposed and is shown to compare well with measurements on all 15 cladding systems used in the experiment work. An empirical prediction model is also compared.

Prediction of the Sound Reduction of Commercial Double-Skin Profiled Metal Cladding Systems

“…The constituent SR1 can either be measured or predicted. When combined with the single skin prediction procedure described in an earlier paper [2], this theory provides a completely predictive procedure for determining the SR1 ofdouble-skin pro led metal cladding systems.…”

“…Previous research [1,2] has studied the sound transmission through single-skin cladding systems in detail. It was found that the sound reduction index (SKI) of these systems is generally characterized by large "dips" at mid-frequencies, and that these dips are linked to distinct vibration modes whose shapes repeat over each pro le corrugation period.…”