A coupled FEM-BEM formulation in structural acoustics for imaging a material inclusion

A rectangular plate, point supported at four corners, is irradiated with a normally incident acoustic wave. The plate has an inclusion embedded in it supposedly at an unknown location. A structural-acoustic coupled formulation using FEM and BEM is developed and the inclusion is imaged (located) from the surface displacement response of the plate. The efficacy of the formulation is demonstrated by varying the location, size, geometry, and material properties. For variations in location, size, and geometry of the inclusion, the method is seen to give satisfactory results. The frequency of the incident wave is limited to 4775 Hz due to the available computing power. This limits the smallest size and clarity of the image for certain cases. For some cases where the material properties are widely different, and where one would expect the results to distinguish the two materials clearly, the image clarity is less than satisfactory. A list of factors is presented for possible future work.