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Re: The Wood Matters *Pic*
By:Nick Schade - Guillemot Kayaks
Date: 4/26/2002, 12:48 pm
In Response To: Re: I would like jump in here (Andreas)

: I am an engineer and worked in aircraft design for a number of years. You are
: mixing two very different problems.

: 1. Stiffness and strength: If you calculate the strength of the Cedar with
: fiberglass, you will see that the cedar has only a small influence on the
: strength. All bending loads are carried in tension and compression by the
: outer skin (fiberglass). Once you get close to the failure the bond to the
: cedar becomes important. If the fiberglass is able to seperate from the
: cedar core in compression, it will buckle and break, thus the laminate
: fails. If the bond is excellent you may see the layer in tension fail
: (depending on lay-up).

Note that testing shows a significant grain dependance on both strength and stiffness of strip built layups. In the graphs below of force vs deflection of a sample of 1/4" thick cedar with 6 oz glass, two layers on one side, one on the other, samples C1 - C4 are bent with the grain and C5 - C8 are across the grain.

While this grain dependance does not necessarily prove that the wood contributes strength to the layup, it does demonstrate that it the very least "influences" the strength.

I think it is a mistake to treat the wood as just-another-core with a response just like a homogeneous foam. Wood has a toughness and strength you just don't find in man-made composites.

Strip built panel strength testing.

Messages In This Thread

Launching: photos?
Mike Loriz -- 4/23/2002, 9:16 pm
Another pic
Mike Loriz -- 4/24/2002, 10:40 am
Newbie contruction review, hardwood difs
Mike Loriz -- 4/24/2002, 2:18 pm
Re: Newbie contruction review, hardwood difs
Sam McFadden -- 4/25/2002, 12:56 am
Re: Newbie contruction review, hardwood difs
Mike Loriz -- 4/25/2002, 9:17 am
Re: Newbie contruction review, hardwood difs
Sam McFadden -- 4/25/2002, 11:27 am
Re: Newbie contruction review, hardwood difs
Andy -- 4/27/2002, 11:09 pm
Re: Newbie contruction review, hardwood difs
Sam McFadden -- 4/28/2002, 9:52 pm
Re: Newbie contruction review, hardwood difs
Mike Loriz -- 4/25/2002, 1:07 pm
Re: Newbie contruction review, hardwood difs
Sam McFadden -- 4/25/2002, 11:39 pm
Re: Newbie contruction review, hardwood difs
Mike Loriz -- 4/26/2002, 10:15 pm
Other species
Sam McFadden -- 4/27/2002, 12:09 pm
Re: Other species
Mike Loriz -- 4/28/2002, 9:10 pm
Re: Other species
Sam McFadden -- 4/28/2002, 9:45 pm
Re: Other species *Pic*
Nick Schade - Guillemot Kayaks -- 4/29/2002, 9:14 am
Re: Other species
Sam McFadden -- 4/29/2002, 5:27 pm
Go with the old wood/canvas canoe model
Paul G. Jacobson -- 4/27/2002, 12:48 am
Re: Go with the old wood/canvas canoe model
Mike Loriz -- 4/28/2002, 8:49 pm
Re: All Wood
Nick Schade - Guillemot Kayaks -- 4/26/2002, 10:06 am
No angels, pins or dancing needed :)
Paul G. Jacobson -- 4/25/2002, 9:10 pm
Re: No angels, pins or dancing needed :)
Mike Loriz -- 4/26/2002, 10:04 pm
Re: No angels, pins or dancing needed :)
Sam McFadden -- 4/25/2002, 11:24 pm
I would like jump in here
David Hanson -- 4/25/2002, 4:51 pm
What about using 1/8" Red Elm for strong strips?
John Monfoe -- 4/26/2002, 7:22 am
Re: What about using 1/8" Red Elm for strong strip
Mike Loriz -- 4/26/2002, 9:42 pm
Re: What about using 1/8" Red Elm for strong strip
John Monfoe -- 4/27/2002, 6:17 am
Re: What about using 1/8" Red Elm for strong strip
David Hanson -- 4/26/2002, 11:44 am
Use both feet :)
Paul G. Jacobson -- 4/25/2002, 9:58 pm
Re: I would like jump in here
Mike Loriz -- 4/25/2002, 9:40 pm
Now we are getting somewhere
David Hanson -- 4/26/2002, 11:36 am
Re: Now we are getting somewhere
Mike Loriz -- 4/26/2002, 9:33 pm
Re: I would like jump in here
Andreas -- 4/26/2002, 10:44 am
Re: I would like jump in here
Mike Loriz -- 4/26/2002, 9:04 pm
Re: The Wood Matters *Pic*
Nick Schade - Guillemot Kayaks -- 4/26/2002, 12:48 pm
Its a bird its a plane its a .....?
!RUSS -- 4/26/2002, 5:34 pm
Re: Its a bird its a plane its a .....? *Pic*
Nick Schade - Guillemot Kayaks -- 4/28/2002, 11:55 am
Re: The Wood Matters - You are right
Andreas -- 4/26/2002, 2:47 pm
Re: Credit *Pic*
Nick Schade - Guillemot Kayaks -- 4/26/2002, 5:16 pm
Re: Credit
Andreas -- 4/26/2002, 6:16 pm
Re: Delamination
Nick Schade - Guillemot Kayaks -- 4/28/2002, 12:41 pm
Re: Delamination
Mike Loriz -- 4/28/2002, 10:43 pm
Re: Delamination
Sam McFadden -- 4/30/2002, 12:08 am
Re: Delamination
Mike Loriz -- 4/30/2002, 12:37 pm
Calculations
Sam McFadden -- 4/26/2002, 12:43 pm
Re: Calculations
Mike Loriz -- 4/26/2002, 9:19 pm
Re: Newbie - Not!
Chip Sandresky -- 4/24/2002, 3:05 pm
Re: Newbie - Not!
Mike Loriz -- 4/24/2002, 7:06 pm
Re: Newbie - Not!
Steve Frederick -- 4/24/2002, 10:22 pm
Re: Newbie - Not!
Mike Loriz -- 4/25/2002, 8:44 am
Re: Launching: photos?
Mike Loriz -- 4/24/2002, 10:35 am
Re: Launching: photos?
Nick Schade - Guillemot Kayaks -- 4/24/2002, 9:35 am
Re: Launching: photos?
Bobby Curtis -- 4/23/2002, 11:14 pm
Re: Launching: photos?
Mike Loriz -- 4/24/2002, 7:00 pm
Doh!!
Sam McFadden -- 4/23/2002, 11:01 pm
Re: Launching: photos?
daren neufeld -- 4/23/2002, 10:29 pm
Great!
Sam McFadden -- 4/23/2002, 10:55 pm
Re: Great!
Mike Loriz -- 4/24/2002, 6:57 pm
Re: Launching: photos?
John Schroeder -- 4/23/2002, 10:17 pm
Re: Launching: photos?
Ronnie -- 4/23/2002, 9:28 pm