Originally Posted by
sblock
Gee, I don't mean to tell you that you're wrong (sounds too harsh!), but your familiarity with the term 'rheology' is perhaps just a bit too limited. Yes, both thixotropy (shear-thinning, like ketchup) and rheopecty (shear-thickening, like cornstarch in water) are considered to be rheological properties, that is, behaviors relating to material flows. These properties are often exhibited by so-called "non-Newtonian fluids," that is, fluids without simple viscous behavior, and also by certain fluid-solid mixtures (e.g., slurries; you brought up the example of fluidized beds from your engineering background), and by fluids mixed with either long or branched polymers. And under SOME (not all conditions), it might even be appropriate to model wood as a viscoelastic plastic (which means a deformable semi-solid!) that exhibits hysteresis -- as, for example, when it's being SLOWLY bent and set into a shape by heat. But this same physical model is NOT at all appropriate when considering how wood acts as a vibrating medium during sound production, so one has to be careful about picking the right model! The importance differences involved here have to do with (1) very different time scales, (2) different temperatures, and (3) different stresses.
That said, one can certainly talk about wood from a rheological perspective some of the time. I am not sure, though, that simply using science-jargon terms like this leads to greater insights. The devil is always in the details, and the agreement of any possible rheological models with actual experiment. But science is great when it's applied appropriately -- which is when it works! And engineering the the 'art' of reducing science to practice, you could argue.
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