Nabeel Alshabatat and Tamir Shaqarin
Keywords: Thin-walled beams, natural frequency, sound radiation, genetic algorithm.
Abstract: Avoiding resonance and reducing the sound radiation from vibrating beams are crucial objectives in structural design. In this paper, a simple approach for optimizing the natural frequencies and minimizing the radiated acoustic power from vibrating thin-walled beams is presented. The method is basically based on bending the beams at specific key points. The out of plane coordinates of these key points are chosen as design variables. Bending the beam alters its stiffness and its mode shapes and as a result changes its natural frequencies and the radiated sound power. The design method couples the finite element method for modal and harmonic analysis, the Lumped Parameter Model (LPM) for sound power calculation, and Genetic Algorithm (GA) for the optimization process. Several examples using bending technique are provided. The optimization results show the efficiency of bending technique in modifying the natural frequencies and reducing the sound radiation from vibrating clamped beams.
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