Experimental validation of a FEM-MFS hybrid numerical approach for vibro-acoustic prediction

Abstract

The interest of scientific and technical communities in the re-radiated noise phenomenon has been increasing over the last years, motivated by complaints of inhabitants living in buildings located next to sources of vibrations. The study and quantification of low-frequency noise levels inside these buildings demand accurate methods of prediction. Thus, the present paper aims to contribute to the listed goal by presenting an experimental validation of a 3D FEM-MFS hybrid numerical model, where the Finite Element Method (FEM) is used to evaluate the structural response and the Method of Fundamental Solutions (MFS) is adopted to assess the acoustic response inside a closed space. The experimental work carried out consisted in the excitation of a reduced-size acoustic chamber by applying an impulse load induced by an instrumented hammer. The structural and acoustic dynamic responses of the system were simultaneously monitored by a set of accelerometers and microphones. The case study was then modelled and the experimental data compared with the numerical results, showing that the numerical approach used is efficient and accurate, as it correctly addresses realistic situations involving re-radiated noise by elastic structures.