Investigation of the Effects of Polyurethane Foam Reinforcement Thickness on Modal Properties of Sandwich Beams

In this study, the effects of polyurethane foam (PUF) reinforcement thickness on modal properties (natural frequency, mode shape and damping ratio) of sandwich beams were investigated. For this purpose, two types of PUF reinforced beams were used. The one of these was reinforced onto one surface of aluminum metal face sheet and the other was reinforced between two aluminum metal face sheets were produced. Each type was prepared in different PUF thicknesses from 10 mm to 50 mm. The modal properties were obtained by using experimental modal analysis (EMA) method for both types