 This image is the result of a finite element analysis of a soundboard from a production concert grand harp (L&H Style 23). It shows the stress levels in the wood. The obvious concentration of stress in the center of the soundboard is clear. Good engineering principles would dictate that the center of the board be made strong, while the rest of the structure can be lightened to allow it to vibrate more freely. This study is the basis for our soundboard designs. Note that only half the board is shown. Since the soundboard and the stress are symetrical about the centerline of the soundboard, this is all that was necessary. The actual stress levels are color coded, as shown in the chart. The fiber stress is indicated in Paschal, for I was working with Metric measurements. |