CA gluing Grand Pinblocks....My take on it/ Richard Brekne

Richard Brekne Richard.Brekne@grieg.uib.no
Thu, 01 Aug 2002 03:01:42 +0200


Terry Farrell wrote:
> 
> Boy, a picture would be worth a thousand words. I am just
> talking about a pin in a hole in maple. Push it to one
> side. You will have tensional forces between the pin and
> wood on the side of the pin where the force was applied.
> You will have compression forces 180 degrees to the
> tension forces. And you will have shear forces between the
> pin and the wood along a plane parallel to the pushing
> force (90 degrees from the compression and tension
> forces).
> 


Ok.. I can buy this.... I think. Tho I would feel more
comfortable with your last sentence if it read :

"And you will have shear forces applied TO the pin by the
string and bridge along a plane parallel to the pushing
force"

Perhaps this makes more clear where I am getting hung up on
what you, Keith, and Joe seem to be saying. I dont see any
shear force being applied TO the bridge..., only from it TO
the pin, and only at the exact point that is on the plane
between the bridge surface and the string. 

When you say there are shear forces BETWEEN the pin and the
maple, I start looking for some sliding motion possibilites
between these two.... and I dont see what the string pushing
on the pin can do to cause any.

Are we any closer ??

Cheers
RicB


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