VIBRATION AND SOUND RADIATION OF SANDWICH BEAMS WITH HONEYCOMB TRUSS CORE

摘要

The vibrations of and the sound radiation from sandwich beams with truss core are here analyzed. The structure of the core is composed of a sequence of identical unit cells repeating along the beam length and across the core thickness. Each cell is composed of beam elements assembled to form a frame structure. Layouts with honeycomb patterns arranged through the thickness of the core are considered. This design represents an alternative with respect to the traditional application of honeycombs in sandwich construction. The proposed configuration provides sandwich beams with interesting structural as well as acoustic characteristics. A spectral finite element model is developed to evaluate the structural and the acoustic behavior of the considered class of sandwich beams. The spectral model can be easily coupled with a Fourier Transform based analysis of the sound radiated by the fluid-loaded structure. The model predicts the performance of beams with various core configurations. The comparison is carried out in terms of vibration and sound radiation in an unbounded acoustic half-plane. Hexagonal and re-entrant honeycomb configurations are considered to study the effects of core geometry on structural response and acoustic radiation.