Soundboard stiffening

Richard Brekne Richard.Brekne@grieg.uib.no
Wed, 04 Feb 2004 19:16:31 +0100


Delwin D Fandrich wrote:

>>>/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./
>>>      
>>>
>>But this is not something I've heard before. In essence a declaration
>>that ribs do indeed (at some point) help in supporting the load.... in a
>>CC board. Tho why  should this support suddenly exist as soon as the ribs
>>are flat instead of being there all the time (perhaps countered by the
>>tendancies of the ribs to straighten to a lessening degree as said ribs
>>approach becomming straight).
>>    
>>
>
>
>Please go back and read what I wrote about Baldwin's crowning technique. And
>then put what I wrote above in its proper context.
>
>Del
>  
>
I think I understood well enough both what you said and the context.  
Interesting stuff to be sure... two ways to interpret the change in 
spring load you are describing... either and abrubt change could be 
observed at the moment the ribs became straight... or a gradual change 
would be observable... closer to exponential in nature... which seems to 
be along the lines of what you say you measured... but then how does a 
gradual increase in stiffness coincide with an abrubt change in the 
nature of rib support for crown ?   It would seems to me that if  ribs 
did nothing to support crown until  they were flat.... indeed aid in the 
effort to flatten the panel... then incremental increase in panel 
stiffness for increase in downbearing would not be possible.. or what ?

RicB




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