Mil-Hdbk 17 Queries 1

[stm6602]

Hi everyone, I'm looking for material properties for Kevlar/Aramid composites. I've looked into Mil-Hdbk 17, to find out if its available. In 17-2F, Chapter 5, I found that it is just an empty section. This 17-2F was downloaded from the internet.

I also realised that we can purchase this reference and the CD retails for around US$550/-. If anyone has the retail version, perhaps you can advise if it is complete?

In addition, Annex A in Mil-Hdbk 17 seems to be highly guarded. Is it available commercially? How do we get it officially?

Your advice will be most appreciated.

Rgds

Lee

 

[SWComposites]

The Kevlar/Aramid section is still empty. To date, no data for that material has been submitted to the Handbook.

from the web site:

http://www.cmh17.org/resources.aspx

:

The Volume 2 Annex (under export control) will be available by sending a request with proper certification (DD Form 2345) to Director, U. S. Army Research Laboratory, Weapons and Materials Directorate, ATTN: AMSRL-WM-M, Aberdeen Proving Ground, MD 21005-5069.

 

[berkshire]

stm6602
Why not go to the source, the manufacturer, and ask them.
Here is a link to DuPont.

http://www2.dupont.com/Kevlar/en_US/tech_info/index.html

B.E.

 

[RPstress]

Some preliminary data is available for an AGATE qualified material from Parker: Nelcote E765/285 4HS Kevlar 49.

http://www.parkelectro.com/parkelectro/nelcote_E765_Agate.asp

You need to register to get access.

Cytec and Hexcel often include representative lamina test data in their resin datasheets, usually for carbon reinforcement, but sometimes for Kevlar, e.g. for Cycom 7714:

http://www.cytec.com/engineered-materials/products/Datasheets/CYCOM 7714.pdf

Occasionally you can find laminate data, but I'm not aware of any for Kevlar laminates.

There is a lack of open hole compression, as well.

Be very cautious with these sorts of data. Generally they can be used for preliminary sizing, but no more than that.

Kevlar fiber is particularly vulnerable to hot/wet conditions. Cytec's 7714 data drops from a lower bound of 25 ksi at R.T. to 15 ksi at 160 deg F, and this is (probably) not wet.

 

[drcomptech]

One website that is useful for finding Prepreg composite properties is

http://www.ides.com/prospector/composites.asp

They have some data from hard to find composites and also composites that aren't commercially produced any more.

Hopefully this helps.

 

[wes616]

Beware of using manufacturers data. Samples are fabricated in an ideal lab environment, and are usually more "defect free" than comparable samples from a manufacturing environment. Additionally there may be process variation based on your structure, tooling and equipment that will invalidate the data provided by the manufacturer.

Wes C.
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[PanelGuy]

Try Eric Green's old manual at

http://www.marinecomposites.com.

One of the more useful pieces of literature out there.

 

[RPstress]

I just found some ply A- and B-basis data for a Tencate material with Kevlar 49.

http://www.tencate.com/TenCate/Aero...ata/TechData/BT250E-1 Allowable Tech Data.pdf

If that's a bit long

http://www.tencate.com/smartsite.dws?id=3339

and click the 'technical data' pdf logo.

The data is vague about fibre volume.