Research on measurement technology of sound transmission loss in variable temperature environments

Abstract

A new experimental technique of sound transmission loss (STL) is proposed to investigate the influence of temperature on the STL characteristics of composite panels in this paper. The advantages and disadvantages of acoustic transmission loss measurement methods currently being used in aerospace are compared. Considering the practicability of engineering applications, the sound pressure method is chosen as the experimental method of this study. Based on the principle of the sound pressure experiment method, the experimental process of STL in a variable temperature environment is designed. The effect of adiabatic and humidity conditions involved in temperature control is considered, and an experimental scheme of STL is constructed. Accordingly, a mobile, temperature-controlled, and moisture-controlled reverberation simulator is designed and produced. Then, an STL experiment of a composite aircraft panel is carried out at different temperatures by using this device. The feasibility of the technology is verified and the phenomenon that the STL of the composite panel is affected by temperature is found in this experiment. The development of this technology provides a new tool for the acoustic design of composite structures in the present and future.