CONTRACT (SANITIZED)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03642A001300040002-1
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 2
• Document Creation Date: December 22, 2016
• Document Release Date: June 14, 2012
• Sequence Number: 2
• Publication Date: February 21, 1957
• Content Type: LETTER

Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642A001300040002-1
V
25X1
21 February 1957
(. c r A 25X1
25X1
This is the third of ex informal ieg of letter reports concerning the 25X1
progress under Contract for the period 1 January to 15 Feb-
ruary 1957.
We have been pursuing in this interval one of the areas indicated in the
last informal report. This deals with the mechanical properties of pres-
surized bodies. I believe that the extension and enlargement of this work
my extend the current understanding of all lighter-than-air vehicles and
could ultimately dictate me.ny of the important design parameters.
Up to this time we have been considering bodies of anifuxm cross section
for simplicity. An example of this is a pressurized cylinder. It can be
shown that the change of potential energy within any such system is:
.there p and V are the pressure and vole a of the body and po is the ambient
p'essure. Using this expression, the compressional and bending character-
istics of bodies of several different cross sections have been determined.
It is interesting to note that each of these solutions has the same general
result for a particular type of bending. Using these general results, ve
have found that any particular pressure beam of uniform cross section bas
a specified bending strength linearly dependent on its cross sectional area,
the maximum thickness in the direction of the applied force, the pressure
differential and an inverse depending on its length. Calculating the bend-
ing strength of, for example, a cylindrical nylon beam which is 50 feet is
length, 2-3/4 feet in diameter, and weighing 15 pounds, it is found that the
beam could support at least 400 pounds at its mid point when supported at each
end. This remarkable demonstration o strength to weight can be verified
laboratory tests. DOC 2..REY DATE 1h I
EY
ORIG COMP . OP4 TYPE
'
ORIC CLASS !
1 P? CIS .._.. REV ?L,A$1 ~. N! 7
MUST _ MIT 11Y .,.- Ate' Y! il I
Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642AO01300040002-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642AO01300040002-1
0 w
21 February 1957
Page two
We are no Attempting to calculate the mechanical properties of beams which
have non-uniform cross sections such as exist in streamlined shapes or even
balloon shapes. It can be seen that this work is vital to the clear under-
standing of wha:, bending moments may be zpplied to nit only the streamlined
body bat also to its inflatable con`i'ol surfaces.
We have also begun a prelim nary analysis of the requirements to provide
stability to this type of \eaicle. Here again, some cf the literature which
we have surveyed contains .''.sufficient information to adequately specify
what type of si ze of control s-irfaces i s necessary for a given case.
The materials testing laboratory has completed an extensive survey of various
barrier materials, including several plastic films, papers and some cloths.
This report is cf a fairly extensive nature and will not be discussed here.
In order to summarize our work up to this time, a quarterly report will be
prepared during the next six weeks. This report shall include all work up
to this time and will specify the areas of study which require additional
research.
As 0f 20 January 1957, 7J per cent of the pr')ject funds remained.
Sincerely yours,
reo:,hysics Section
I - ..--AV -.1
Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642AO01300040002-1