Estudio vibro-acústico e intensimétrico de las transmisiones por flancos en edificios

Laburpena

This thesis resumes the work done to study the acoustical performance of several building construction types proper from the south of Europe. It was made special attention to the flanking contribution. Initially, it was performed an exhaustive study of the existent bibliography with the aim of identifying and valuing the several acoustic experimental measurement methods related to the estimation of flanking contribution. Therefore, three possible applying methods were found: (i) Sound pressure method used in combination with elements shielding; (ii) Sound intensity method capable of obtaining the most reliable results without using the shielding process; (iii) Vibration velocity measurement procedure whose foundation lies on the relation between the vibration velocity of each element and the different flanking paths. This method is based on the velocity measures obtained from the transmitted vibrations by these elements, which are converted on acoustic estimation. From these three measurement methods the sound intensity is the only standardized and allows quantifying the contribution of each flanking path separately. For that reason, the intensity method was used as reference. It was also compared with the sound pressure method, respecting the estimation of airborne sound insulation without including the flanking contribution, and with the vibration velocity method when considering the flanking transmission. There were performed several experimental measurements to compare the results in laboratory and field conditions, for both structure and airborne sound transmission, through the three measurement methods. Taking the results obtained in consideration it is intended to establish a vibration velocity method as a measurement procedure on the estimation of airborne sound insulation with flanking contribution evaluation. At the same time it was calculated the sound insulation prediction by means of the methods referred on the EN 12354-1 (2000). Gathering all this information and comparing all the results, it is possible to conclude if the prediction methods are suitable for the south European countries, especially to the Spanish buildings. It must be referred that the vibration velocity method is only capable of producing results through the application of mathematical models which simulate the radiation efficiency estimation. The authors of these models were selected, as the most recent and known, among the bibliography and their models were applied to the specific conditions found for this thesis. These results were expressed by means of graphics representing vibrational velocity levels spatially distributed. The experimental work developed for this thesis implies a profound knowledge of all the measurement methods, and allowing obtaining data capable of concluding on the advantages and disadvantages of each method. Finally, conclusions and specific proposals are presented in order to stimulate the development of new studies.