Improvement of the concert harp through the application of composites
Curt Preissner, Thomas J. Royston · The Journal of the Acoustical Society of America · 2001
The replacement of a Sitka spruce grand concert harp soundboard with a fiber-reinforced plastic soundboard was considered for improved durability and long-term stability. First, a means of nondestructively identifying the structural acoustic properties of a conventional wooden soundboard was developed based on a multi-mode dynamic identification technique available in the literature. This was followed by the development of a design process to reproduce the same structural acoustic properties in the composite replacement. It was found that specific matching criteria must be met to achieve a dynamic response that closely approximates the wooden soundboard. Lay-up of the composite soundboard was guided by this matching criteria and Tsais orthotropic plate design procedure. Experimental verification was then performed utilizing the same system used to identify the wooden plate properties. The identification technique and composite replacement design process may be applicable to other musical instruments, as well as other nonmusical, orthotropic plate structures.