composite design

Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

--

FF

I took a composite stress analysis mechanical engineering class at a
major university (the only class offered). We didn't use any textbook,
but used a series of pdf files. Anything in particular you looking
for?


On 21 Jan 2005 11:51:18 -0800, wrote:

Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

I ran across an excellent book on composites in Barnes & Nobles about a
year ago. It was nearly $70US so I had to pass it by. Been kicking
myself ever since. Sorry, that is the only clue I remember 8-(.

AI Nut


wrote:
Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

There are not that many books that give a begineer a practical overview of
how to design with composites. It is a art leaned by a small number of
engineers who to date have not been very prolific and writing down what they
know .... try the following for starters.

Niu "composite Airframe Structures" not a cheap book but about the best
general intro but it will not give you everything you are going to need.

Tsai, Stephen. W. "Composites Design" Think Composites or the earlier
book by Tsai and Hahn (actaually better in some respects that the later Tsai
volume IMHO)

Daniel and Ishai "Engineering Mechanics of Composite Materials"

I will post more referenes on monday and I get to work .... cannot remember
them all right now.

You are going to need design allowables ... if doing a simple wet layup then
perhaps the best source of such data is the old ANC-17. This was replaced by
MIL-HDBK-17 but this only contains data for a lot of more advanced prepreg
materials.

If you want to use prepreg than my guess is that it will be a low
temperature cure material and the best source of data for these materials
are the AGATE style data bases supplied by many of the manufacturers such as
Fibercote, Toray and Newport for their materials.

Actually some of the best sources of info are the design manuals from some
of the large airplane manufacturers - if you can get hold of them. This is
because a lot of the more practical aspects of design and analysis are
simply not covered in the more academic texts.

I would not recommend the popular 2 volume book from a well know engineer of
homebuilts. They are really too superficial .... they lack any real meat
IMO. Interesting background info but probably not worth the price if you are
expecting a design text.

You cannot really design composite structures without some software as well
.... as a minimum you will need a laminate analysis program such as Tsai's
Genlam. Ideally you will have an FEA program that has laminate elements.

There are a lot of courses out there on composite design but in reality most
of these should be called an intro to laminate theory or something. My
experience is that they usually don't talk much about the practical issues
and problems associated with the design of composites (allowables, hot wet,
strain limits, through thickness and edge effects etc) ... concentrating
instead on the more academic aspects of pure analysis.

Also check the FAA web site there are some interesting AC's, Memo's,
research reports etc that address some of the major issues ... this is the
sort of info you will not find in text books and university courses.

Finally grab some repair manuals for certificated composite airplanes and
gliders ... many of these show details of all the laminates (materials, #
ply's, ply orientation etc). A careful study of some airplanes designed by
people who know what they are doing can be worth more than a dozen texts.

If you have specific questions fire away.

wrote in message
ups.com...
Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

--

FF

As per my previous post ... here is some additional references for use in
the design of composite structures:

Agarwal and Broutman "Analysis and Performance of Fibre Composites"

Armstrong K.B. & Barrett R.T., Care and repair of Advanced Composites, SAE,
Warrendale, PA, 1998.

Ashton, J.E. and Whitney, J.M. "Theory of Laminated Plates"


Ashton, J. E., Halpin, J. C. and Petit. P. H. "Primer on composite
materials: analysis"

Baker A.A. & Jones R., Eds., 1988, Bonded Repair of Aircraft Structures,
Martinus Nijhoff Publ., Dordrecht.

Bitzer, Tom. "Honeycomb technology : materials, design, manufacturing,
applications and testing"

Christensen, J. "Mechanics of Composite Materials"

Hoskin B.C. & Baker A.A., Eds., 1986, Composite Materials for Aircraft
Structures, AIAA Education Series, AIAA, New York.

Hull, D. and Clyne, T.W. "An introduction to composite materials"

Jones, R.M. "Mechanics of Composite Materials"

Kollar, L.P. and Springer, G.S. "Mechanics of composite structures"

Springer, G. "Environmental effects on composite materials" 3 volumes

Schwartz, M.M. "Joining of Composite Matrix Materials"

Schwartz, Mel M. (Ed). "Fabrication of composite materials"

Schwartz, Mel M. "Composite materials handbook"

Schwartz, Mel M. "Composite materials"

Whitney, J.M. "Analysis of Laminated Anisotropic Plates"


Whitney, J.M., Daniel, I.M. and Pipes, B. "Experimental mechanics of fiber
reinforced composite materials


The literature is huge ... this is just a start. Do your own research and
you will find a whole lot more.

Robert Dorsey wrote:
I took a composite stress analysis mechanical engineering class at a
major university (the only class offered). We didn't use any
textbook,
but used a series of pdf files. Anything in particular you looking
for?


On 21 Jan 2005 11:51:18 -0800, wrote:

Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

Mr/Ms Mitchell has posted quite a list of books.

My particular interest is in stress analysis so as to be able
to compare strength to weight ratios for various choices of
materials. In particular I'd like to see if there is any
advantage to substituting composite members for wood or metal
members in stick and rag designs. For instance, one could
use swim noodles wrapped in a hard shell of epoxy filled
carbon fiber, glass or kevlar tapes and cloth to make tubular
members.

--

FF

I have a spreadsheet and some files you may like to look at. I had to
do a design project using various fiber materials at different ply
orientations. This included material densities.



On 8 Feb 2005 11:14:44 -0800, wrote:


Robert Dorsey wrote:
I took a composite stress analysis mechanical engineering class at a
major university (the only class offered). We didn't use any
textbook,
but used a series of pdf files. Anything in particular you looking
for?


On 21 Jan 2005 11:51:18 -0800, wrote:

Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

Mr/Ms Mitchell has posted quite a list of books.

My particular interest is in stress analysis so as to be able
to compare strength to weight ratios for various choices of
materials. In particular I'd like to see if there is any
advantage to substituting composite members for wood or metal
members in stick and rag designs. For instance, one could
use swim noodles wrapped in a hard shell of epoxy filled
carbon fiber, glass or kevlar tapes and cloth to make tubular
members.

I have contemplated something similar.

I think you would be best to wind the tubes using a carbon / glass tow
material and epoxy around a mandrell. Tow would be a lot cheaper then
wrapping the tubes in cloth and would allow the properties of the tube to be
optimised by changing the winding angle.

Pro's and Con's ....

It is going to cost more than alumnium.
Might save a little weight.
Joints will be hard to make at intersections of tubes.
The composite tubes will lake the ductility of the alumnium tubes and hence
crashworthiness will be compromised.


wrote in message
ups.com...

Robert Dorsey wrote:
I took a composite stress analysis mechanical engineering class at a
major university (the only class offered). We didn't use any
textbook,
but used a series of pdf files. Anything in particular you looking
for?


On 21 Jan 2005 11:51:18 -0800, wrote:

Any recommendations for textbooks addressing designing, especially
stress
analysis, with composite materials?

Mr/Ms Mitchell has posted quite a list of books.

My particular interest is in stress analysis so as to be able
to compare strength to weight ratios for various choices of
materials. In particular I'd like to see if there is any
advantage to substituting composite members for wood or metal
members in stick and rag designs. For instance, one could
use swim noodles wrapped in a hard shell of epoxy filled
carbon fiber, glass or kevlar tapes and cloth to make tubular
members.

--

FF

.......... :-)) wrote:
I have contemplated something similar.

I think you would be best to wind the tubes using a carbon / glass
tow
material and epoxy around a mandrell. Tow would be a lot cheaper
then
wrapping the tubes in cloth and would allow the properties of the
tube to be
optimised by changing the winding angle.

Pro's and Con's ....

It is going to cost more than alumnium.
Might save a little weight.
Joints will be hard to make at intersections of tubes.
The composite tubes will lake the ductility of the alumnium tubes and
hence
crashworthiness will be compromised.


Wrapping in cloth or tape would be a lot easier and faster if doing
the layup by hand. It would also be trivial to orient it so that
half the fibers of the cloth or all the fibers of unit-directional
tape run the length of the tube to maximise bending strength.

Before doing anything of the sort I want to be able to calculate
that strength, hence the original question.

Joints could be made with tows/cloth/tapes to fabricate saddle-like
fittings perhaps in-situ.

Crash-worthiness remains an important issue.

--

FF

My two cents: for a reasonably simple structure such as the "carbon
around swim tube" proposed, I think the best approach may be to simply
build one or two of them and test it/them to destruction. Compare this
against a likewise destructive test of the wood part you're proposing
to replace. Allow a generous margin for error -- especially if others
are going to be building it from your plans, because there can be a
great variance in composite strength depending on the builder's skill
and environmental conditions.

Greg