Investigation Thickness Effects of Polyurethane Foam Core Used in Sandwich Structures via Modal Analysis Method

Abstract

Abstract-In this study, the effects of reinforcement thickness of polyurethane (PU) foam used as viscoelastic core in sandwich structures for vibration isolation were investigated. For this purpose, three different sandwich structures were prepared by using ST37 450x450x0.9 mm3 plates and PU foam in 16, 26 and 36 mm thicknesses. For each sandwich structure, the dynamic properties (natural frequencies, mod shapes, damping ratio) were obtained by using experimental modal analysis method. Also, the experimental results were compared with the results obtained from ANSYS finite element method. For the first five modes, natural frequencies and damping ratios of PU reinforced sandwich structures were observed to increase with PU foam reinforcement thickness.