Delwin D Fandrich wrote: > > > What this adds up to is that somehow or another... just because the > panel gets > > pushed flat... the panel can remain stressed big time (compressed) yet > all the > > stresses in the ribs have just disapeared... no tension in the top and no > > compression in the bottom. I dont see how a rib can get into this > state... > > where it is exerting a huge compression force on the panel, while not > > experiencing a tensioning force in return. I'm not saying it isnt > possible... > > I'm just saying I dont see how that can be. > > > > RicB > > About a year or so back -- during one of the many times this subject has > come up -- I outlined a rather simple experiment illustrating at least some > of these principles. Did you ever conduct this experiment for yourself? > > Del > Yes, I did,,, just a little while back actually. And you are right... they demonstrated some of these principles nicely... but they dont tell me whether or not the tensioning on the rib simply bends the thing, or if it actually tensions the rib slightly as a whole as well as bending it. In fact... I cant find anything anywhere in the literature that actually deals with this kind of situation at all. Several on the list have re-iterated the status quo << statement of fact >>.. but nobody has actaully pointed to anything specific in the available literature that can defend the position. Im sorry.. but my mind questions these kinds of things.. and needs an answer somewhat more complete then a couple "Because I said so's" form a few folks around town as it were. Let me ask you this... say the panel was steam bent into permant curved shape instead of "crowned" per se.... same shape tho.. no drying out of the panel.. . THEN you glue these same flat ribs into place. Now THERE I can see the ribs doing nothing more then pulling down on the board. I can see them willingly helping any downbearing because there is no stress in the interface between the wood and rib that goes the other direction. Pondering as usual. RicB -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html
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