Gene Nelson wrote: > Great illustration. Lets see if I got it right: >> From its birth as a dry flat panel glued to flat ribs it swells as it >> takes > up moisture. Yes. > Bottom of board gets compressed, top may have tension, top of rib in > tension and > bottom in compression. No. The entire panel is under compression. You aren't just bending the panel in a curve. The panel expands and pushes the curve into the rib, and itself. >The constraint of the ribs maintains this state > with or without > string bearing load as long as the emc remains higher than glue up. Yes. > The assembly would need to be dried to 4% or so in order to > release the compression/tension. Right (compression anyway), Or until the panel has crushed enough through cyclic humidity swings and general overloading to lose it's ability to maintain those compression levels. Ron N
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