Modal Analysis of Upright Piano Soundboards by Combining Finite Element Analysis and Computer-Aided Design
Keywords:Modal analysis, piano soundboard, finite element analysis, computer-aided design
AbstractThis study presents a visual model for analyzing the vibration modes of piano soundboards by combining the tools of finite element analysis and computer-aided design. Based on the predicted results from the model, changes of natural frequency and maximum displacement of the soundboard as a function of wood properties, structure, and rib size were discussed. Wood grain direction affected the mode shape of the soundboard. Among the 10 property factors investigated, density presented the greatest impact to the vibration mode of the soundboard followed by Young's modulus, shear modulus, and Poisson's ratio. Increasing the thickness of the resonance board and the use of ribs had positive impacts on the natural frequency of the soundboard. However, the amount of natural frequency was decreased for those that were lower than 100 Hz. Natural frequency increased as the intensity, density, and size of ribs increased. Rib height had a greater effect on the variation of natural frequency than the intensity, density, and rib width. In general, increases in rib intensity, density of wood species, and rib width presented negative effects on the maximum displacement.
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