Damage localization in composite material structures by using eigenvalue measurements

In this work a methodology for a non destructive control by a modal analysis approach of a composite material structure is presented. The method is based on the use of some eigenvalues of the undamaged and damaged structure together with the sensitivity matrix computed on the numerical model. The minimum number of eigenvalues which are necessary for a correct localization is evaluated by the comparison among the columns of the sensitivity matrix in order to obtain non proportional columns. Some numerical examples on composite material beams show the efficiency of the method. Finally an evaluation of the noise effect on the frequency measurements is carried out.