The sound transmission loss of double walls in the low-frequency range is studied by means of structure-acoustic finite element analysis. The analysis simulates standard experiments to determine sound transmission loss of walls. The model is a detailed description of the geometry of the system, including both the double wall and the rooms acoustically coupled to the wall. The frequency range studied is in the 1/3-octave bands between 40 Hz and 200 Hz. A parametric study is performed to investigate the influence on the sound transmission loss of various material and geometric properties of the wall and the dimensions of the connecting rooms. The model confirms the importance of primary structural resonance and the size of the connecting rooms in determining the degree of sound transmission loss. The primary structural resonance is mainly determined by the distance between the wall studs and the properties of the sheeting material. Wall length is also important; if the length is such that the wall studs of the last wall cavity are closer together than those of the other wall cavities, the primary structural resonance will be at a higher frequency, thereby decreasing sound transmission loss over a broader frequency range. Similar dimensions of the connecting rooms results in poor transmission loss, mainly at frequencies below 100 Hz (for the wall and room dimensions studied here).
To develop new types of lightweight wall and floor structures it is important to increase the knowledge of the transmission and radiation processes for such structures. To do so, detailed models based on deterministic and statistical assumptions may form a valuable tool. In lightweight floor structures, impact sound insulation is perhaps the most important factor to consider. This paper gives an overview of various solution strategies that may be useful in finding a prediction model for impact sound insulation.
Resilient devices are commonly used in lightweight structures to decrease sound transmission in a broad frequency band. Applications of such devices may be found in e.g. resilient mounted ceilings in aeroplanes, ships and buildings. A measurement method to characterise the frequency dependency of the transfer stiffness and the input stiffness of the resilient device is presented. The mechanical characteristics of the measurement method are investigated. In addition, some resilient devices used in buildings are analysed with respect to acoustic properties. Parameters such as static load and mountings for the devices are considered and handled by means of statistical analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.