Download NASA NTRS Archive 20100002800 PDF

TitleNASA NTRS Archive 20100002800
LanguageEnglish
File Size2.1 MB
Total Pages32
Document Text Contents
Page 1

December 2009

NASA/CR–2009-215957





Design and Manufacture of Structurally
Efficient Tapered Struts

Jebediah W. Brewster
Lockheed Martin Space Systems Company, Denver, Colorado

Page 2

NASA STI Program . . . in Profile


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Page 16

14





A comparison between EA9394 and EA9309 on the bondline peel (flatwise tensile) and
shear stress is presented below for both compressive and tensile loading:





EA9309 was chosen over EA9394 based on the following reasons:

• High Ductility
• Flaw Tolerance due to excellent stress redistribution capability
• High glass-transition temperature after post cure
• Stable thermal cycling characteristics
• Good wetting characteristics
• Reduced Stiffness (reduces bondline stresses)

Page 17

15




2.1.5 Composite Evaluation
An investigation into comparing IM-7/5250-4 to M55J/954-3 composite resin systems
revealed that M55J/954-3 was the preferred choice. The properties of both composite
materials at room temperature are given below:

IM-7/5250-4
LAMINA PROPERTIES

(1 -fiber, 2-transverse)
Temp
(°F)

E11
(Msi)

E22
(Msi)

G12
(Msi)

ν12 α11
(10-6/°F)

α22
(10-6/°F)

RT 22.5 1.4 0.90 0.33 -0.12 14.2
M55J/954-3

LAMINA PROPERTIES
(1 -fiber, 2-transverse)

Temp
(°F)

E11
(Msi)

E22
(Msi)

G12
(Msi)

ν12 α11
(10-6/°F)

α22
(10-6/°F)

RT 43.45 0.96 0.435 0.15 -0.55 17.7

M55J/954-3 was chosen over IM-7/5250-4 because of its high fiber stiffness.
Comparing other high compressive modulus fibers showed that M55J is one of the best
because of its high compression and interlaminar (IL) shear strength. Only M60J
showed comparable properties. M55J/954-3 was chosen due to extensive in-house
experience and materials database history.

Page 31

29





Flight Tapered Strut Full Scale Drawing:

Page 32

REPORT DOCUMENTATION PAGE
Form Approved

OMB No. 0704-0188

2. REPORT TYPE

Contractor Report
4. TITLE AND SUBTITLE

Design and Manufacture of Structural Efficient Tapered Struts
5a. CONTRACT NUMBER

NNL04AA12B

6. AUTHOR(S)

Brewster, Jebediah

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center
Hampton, VA 23681-2199

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration
Washington, DC 20546-0001

8. PERFORMING ORGANIZATION
REPORT NUMBER

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

Langley Technical Monitor: Dawn C. Jegley

12. DISTRIBUTION/AVAILABILITY STATEMENT
Unclassified - Unlimited
Subject Category 39
Availability: NASA CASI (443) 757-5802

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: [email protected])

14. ABSTRACT

Composite materials offer the potential of weight savings for numerous spacecraft and aircraft applications. A composite strut
is just one integral part of the node-to-node system and the optimization of the shut and node assembly is needed to take full
advantage of the benefit of composites materials. Lockheed Martin designed and manufactured a very light weight one piece
composite tapered strut that is fully representative of a full scale flight article. In addition, the team designed and built a
prototype of the node and end fitting system that will effectively integrate and work with the full scale flight articles.

15. SUBJECT TERMS

Composites; Structurally efficient; Lightweight; Graphite-epoxy; Tapering; Tailoring

18. NUMBER
OF
PAGES

32
19b. TELEPHONE NUMBER (Include area code)

(443) 757-5802

a. REPORT

U

c. THIS PAGE

U

b. ABSTRACT

U

17. LIMITATION OF
ABSTRACT

UU

Prescribed by ANSI Std. Z39.18
Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

NNL08AD07T
5f. WORK UNIT NUMBER

727950.04.05.23

11. SPONSOR/MONITOR'S REPORT
NUMBER(S)

NASA/CR-2009-215957

16. SECURITY CLASSIFICATION OF:

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,
gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this
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shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

12 - 200901-

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