<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body> Delwin D Fandrich wrote: <blockquote cite="midNCBBLPIFHEMDJHENPLOAOENHCHAA.fandrich@pianobuilders.com" type="cite"> <blockquote style="border-left: 2px solid rgb(0, 0, 255); padding-left: 5px; margin-left: 5px;"> <blockquote cite="midNCBBLPIFHEMDJHENPLOACENGCHAA.fandrich@pianobuilders.com" type="cite"> <pre wrap="">I don't know how gradual or abrupt the transition was. I wasn't testing for that. These were just observations made along the way. Personally, I have no trouble at all understanding why the transition region was incremental. Del </pre> </blockquote> <div>Great !.. then it should be no problem explaining this to the rest of us.  </div> </blockquote> <div>I have already done so.</div> <div> </div> <div>Del </div> </blockquote> Probably me just getting hung up in how whats been said is said again.... regardless somehow I've gotten crossed up here and I'd appreciate getting whatever misunderstandings I have cleared up... The following may help clarify my quandry... You said.... <blockquote> <pre wrap="">"On reflection I suspect this was because the initial load support came entirely from compression within the soundboard panel while the ribs (though lightly crowned they were also moderately bent as in a compression-crowned soundboard system) were actually working to straighten the panel. Once the ribs reached their neutral configuration they began helping the compressed panel in supporting the load rather than fighting it, hence increasing the spring rate of the system."</pre> </blockquote> But this seems like you are saying the increase in the spring rate does not occur until the ribs have become flat, which is not consistant with the incremental increase in stiffness you cited in the paragraph exactly preceeding...where you say <blockquote>As best as I can recall the amount of deflection was greater per incrementat the beginning of the loading. With each increase in weight the board went flatter, but not by as much as with the previous increment. The biggest change in the amount of deflection came at the beginning. Toward the end it was pretty difficult to measure accurately. </blockquote> So...if you please... straight me out on this... Thanks RicB </body> </html>