Doug and List: > Doug Richards wrote: > > > Del, > > > > Thanks a bunch for the modulus and density info. I looked for it a whole > > back and couldn't find it. Can you tell me what type of wood these numbers > > are for? I started to do a simple finite element model of a soundboard with > > a 3 string unison to look at how much the board stiffness changes the > > response of the strings... I need the modulus of both spruce and maple to > > do a more accurate job, but anything you have is better than nothing. > > > > doug richards > > San Jose, CA > > As Del mentioned, the parameters in question are independent of species. You will be able to find mean values of density and MOE for species, but they tell you very little about your own material. Wood is a biological material, and hence not a homogeneous substance, so you cannot define a parameter such as density or modulus of elasticity even for a single sample--they vary within a single tree, more within a stand, even more within a population, and hugely within species. They vary in response to environmental and genetic factors controlling growth rate, fibre length, lignin content, and a host of other factors. If your model is going to tell you anything, you will need to account for variance. (I used to work in tree improvement/forest genetics, largely spruce). Tim Keenan Terrace, BC.
This PTG archive page provided courtesy of Moy Piano Service, LLC