Experimental results of a damage detection methodology using variations in modal parameters

The present paper reports the results obtained by a methodology of damage detection in which combined EMA and FEM data are used to localise the damage on mechanical components. The utilized method uses the eigenvalues and eigenvectors obtained from FE modelling, compared with the eigenvalues obtained experimentally on damaged specimens. The method assumes a linear behaviour of the materials. Firstly it is applied to rectangular plates in order to test its reliability in discovering the damage located on very simply shaped specimens that are made of homogeneous and isotropic material. The methodology was subsequently applied to mechanical components of complex shape, allowing the location of the damage to be accurately identified.