Experimental modal analysis of a rotor with active composite blades

This paper presents a modal analysis of a rotor with three active composite blades performed by different methods. The rotor blades were made of glass-epoxy unidirectional laminate. Active Macro Fiber Composite (MFC) elements were adhered on each composite blades. The experiments were performed on a test stand installed at a Structures Dynamics Laboratory at the Lublin University of Technology. The rotor was fixed during the measurement. A laser vibrometer and LMS analyzer with modal hammer were used. The experimental natural frequencies and mode shapes of free vibrations were determined. The laser vibrometer was equipped with a generator and scanning heads with a video camera. In order to activate vibrations, MFC elements powered by a high-voltage amplifier were used. The experimental results were developed using PSP software. Next, the LMS analyzer with modal hammer was used as force and acceleration sensor. Finally, a numerical modal analysis was performed. The simulations were performed by the finite element method using the Abaqus software package. The numerical results and the experimental findings show a very good agreement. All results were compared with the results of modal analyses for the cantilever composite beam and the fixed rotor with one composite blade.