AN EXPERIMENTAL MODAL-ANALYSIS TECHNIQUE FOR MINIATURE STRUCTURES

This paper describes an experimental modal analysis system which can e ffectively be used to obtain the modal parameters of small structures. The system uses an electromagnetic exciter to produce the excitation force, a piezoelectric transducer to measure this force, and a Laser D oppler Vibrometer to measure the response. Several designs of the magn etic actuator are discussed and evaluated. The system is verified by o btaining the modal parameters of a miniature cantilever plate, using t wo preferred exciter designs, and comparing the measured parameters wi th those acquired from a finite element model. Favorable agreement is obtained between the experimental and computational results. Finally, the two preferred exciters are compared and an optimal configuration i s discussed.