Experimental Determinations of the Eigenmodes for Sandwich Bars with Different Core Reinforced with Metal Fabric

Abstract

In this paper, starting from the theoretical background of modal identification, it is established an experimental method used to determine the eigenmodes of some composite bars with the core made of polypropylene honeycomb and polystyrene reinforced with metal fabric. The single-point excitation method is used. This method has been widely used in modal tests and it consists in applying a force in a given point and recording the vibratory structure response in all interest points, including the excitation point. Although the single-point excitation requires a minimum of equipment, it needs a laborious analysis to perform extensive result processing in order to interpret the dynamic behaviour of the structure under test.