Hi

Would anyone have advice on how the bending stiffness of a fiber-matrix
composite depends on the angle of the fibers? Should be a pretty basic
problem, but I could only find information for the stiffness in tension,
not bending. I would need this to discuss the influence of changes in
the cellulose microfibril angle in wood cell walls on the bending
stiffness of the wood.

Thanks a lot!

Lothar Koehler

Michigan State University

"koehlerl" schreef
Hi

Would anyone have advice on how the bending stiffness of a fiber-matrix
composite depends on the angle of the fibers? Should be a pretty basic
problem, but I could only find information for the stiffness in tension,
not bending. I would need this to discuss the influence of changes in
the cellulose microfibril angle in wood cell walls on the bending
stiffness of the wood.

Thanks a lot!

Lothar Koehler

Michigan State University

You mention:
* bending stiffness of a fiber-matrix composite
* the angle of the fibers in it
* microfibril angle in cell walls
* bending stiffness of the wood
This covers quite a few levels. Hardly looks basic!
PvR

P van Rijckevorsel wrote:
"koehlerl" schreef

Hi

Would anyone have advice on how the bending stiffness of a fiber-matrix
composite depends on the angle of the fibers? Should be a pretty basic
problem, but I could only find information for the stiffness in tension,
not bending. I would need this to discuss the influence of changes in
the cellulose microfibril angle in wood cell walls on the bending
stiffness of the wood.

Thanks a lot!

Lothar Koehler

Michigan State University


You mention:
* bending stiffness of a fiber-matrix composite
* the angle of the fibers in it
* microfibril angle in cell walls
* bending stiffness of the wood
This covers quite a few levels. Hardly looks basic!
PvR

Thanks for breaking it down!! I can see the whole issue much clearer now!

However, my question still remains quite simple: the mathematical
relation between fiber angle and bending stiffness of a fiber matrix
composite.

"koehlerl" schreef
However, my question still remains quite simple: the mathematical
relation between fiber angle and bending stiffness of a fiber matrix
composite.

***
Well, the only thing mildly interesting from a botanical point of view is
"microfibril angle in cell walls". However, this is not all that likely to
affect the properties of a "fiber matrix composite", unless perhaps the
latter is a sheet of paper. So you are asking the wrong group.
PvR

"koehlerl" schreef
However, my question still remains quite simple: the mathematical
relation between fiber angle and bending stiffness of a fiber matrix
composite.

P van Rijckevorsel wrote:
Well, the only thing mildly interesting from a botanical point of view
is "microfibril angle in cell walls". However, this is not all that likely
to affect the properties of a "fiber matrix composite", unless perhaps the
latter is a sheet of paper. So you are asking the wrong group.
PvR

"koehlerl" schreef
When you say that microfibrilar angle in cell walls is only "mildly
interesting" you either just speak for yourself or are wildly ignorant
of all the work out there on MFA and wood properties.

***
Right. What I said was "Well, the only thing mildly interesting from a
botanical point of view is "microfibril angle in cell walls"."
* * *

Matter of factly
the microfibrillar angle is one of the pivotal determinants of
mechanical properties of plant cell walls.

***
And this makes microfibrillar angle a pivotal interest in botany?
* * *

Go try and tell the lumber industry MFA is negligible

***
I don't need to. They will tell me.
* * *

...or the many participants of the IAWA/IUFRO
International Workshop on the Significance of Microfibril Angle to Wood
Quality, Westport, New Zealand November 1997.

***
If you have seen the Proceedings you know what proportion of the
participants occupied themselves with microfibrillar angles
* * *

You're really funny! At least I get a good laugh out of this.

You also seem to be disregarding the tons of papers out there treating
wood as a fiber matrix composite and incorporating results from
materials sciences and engineering into their *BOTANICAL* research.
Below you can find some few examples.

Cave I.D. (1972): Swelling of a fibre reinforced composite in witch the
matrix is water reactive. Wood Sci. & Technol. 6:157-161.
Cave I.D. (1976): Modelling the structure of the softwood cell wall for
computation of mechanical properties. Wood Sci. & Technol. 10: 19-28.
Koponen S., Toratti, T., Kanerva P. (1991): Modelling elastic and
shrinkage properties of wood based on cell structure. Wood Sci. Technol.
25: 25-32.
Navi P. (1988): Three dimensional analysis of wood microstructural
influences on wood elastic properties. Proceedings of the 1988
International conference on timber engineering, Seattle, 915-922.


It still seems I didn't word my initial question clear enough for you to
understand. I'm sorry. Never mind.

LK

***
Well, again, "fiber matrix composite" may cover a lot of ground.
Also, again, this is the wrong group for your 'simple' question.
PvR