I design pianos.  The materials I use are foreign to virtually every other modern industry. Besides specifying material properties for orthotropic materials, such as wood species, the problem is even greater in determining static and dynamic frictional coefficients for material combinations including buckskin, felt, graphite-coated hornbeam and other wood species.  My immediate roadblock is accurately defining frictional variables for rigid body motion analysis.

Another problem relates to thermal dynamics.  Relatively slight temperature changes have the opposite effect on “tonewood,” as would be expected of other materials.  Soundboard spruce does have an expansion thermal coefficient, but higher temperatures reduce moisture content in the wood.  The lower moisture content overpowers the expansion due to temperature, resulting in dimensional contraction, mostly across the grain.

When I bring these issues up with SW tech support, they “look at me” like I have three heads!  Is there anyone out there who has dealt with these issues?

Thanks,

George F Emerson

pianoguru@cox.net