2 INVERSE METHODS FOR LOCALIZATION OF EXTERNAL SOURCES EXCITING A BEAM

We are interested in reconstructing the external force distribution ex citing a beam using measured values of the flexural displacement field . Firstly, two different techniques are developed with remedies for re ducing the sensitivity to the measurement uncertainties. The first met hod based on a finite difference scheme involves local determination o f the applied force density and uses an ideal wavenumber filter and a spatial window for the elimination of the noise influence. The second method based on a modal expansion uses an optimized number of modes fo r the same reasons. Then, an application is proposed that we could nam e ''force analysis of a structure'' where both approaches could be use d. Finally, some experimental results are presented in order to valida te both techniques.