Form Approved
REPORT DOCUMENTATION PAGE
OMB No. 0704-0188
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1. AGENCY USE ONLY (Leave blank)
2. REPORT DATE
3. REPORT TYPE AND DATES COVERED
December 1996
4. TITLE AND SUBTITLE
5. FUNDING NUMBERS
Ballistic Perforation of Graphite/Epoxy Composite
6. AUTHORS
Piyush K. Dutta, Dennis Farrell, Susan Taylor, Aziz Tadayon and David Hui
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
8. PERFORMING ORGANIZATION
REPORT NUMBER
U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
Special Report 96-29
Hanover, New Hampshire 03755-1290
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
10. SPONSORING/MONITORING
Office of the Chief of Engineers
U.S. Air Force Flight Dynamics Laboratory
AGENCY REPORT NUMBER
Washington, DC 20314-1000
Wright-Patterson Air Force Base
Ohio 45433-7542
U.S. Army Research Office
Research Triangle Park
North Carolina 27709
For conversion of SI units to non-SI units of measurement consult Standard Practice for Use of the
11. SUPPLEMENTARY NOTES
International System of Units (SI), ASTM Standard E380-93, published by the American Society for Testing and Materials, 1916
Race St., Philadelphia, Pa. 19103.
12a. DISTRIBUTION/AVAILABILITY STATEMENT
12b. DISTRIBUTION CODE
Approved for public release; distribution is unlimited.
Available from NTIS, Springfield, Virginia 22161.
13. ABSTRACT (Maximum 200 words)
This report documents the experimental details of impact studies performed on graphite/epoxy laminated plates
by spherical projectiles. The mechanism of failure and energy absorption were studied by macro- and microscopic
examination of the surfaces of the laminates. Fragments were examined under scanning electron microscope to
determine presence of any characteristic fracture surface pattern. The influence of laminate orientations was stud-
ied using unidirectional and quasi-isotropic laminates. The scanning electron microscopic examination of the frag-
ments from the impact shows that the fracture surfaces of the matrix have some characteristic hackle marks.
A discussion is provided to explain the characteristics and texture of these hackle marks and relate them to the
impact velocity, material brittleness, and energy absorption of the impact.
14. SUBJECT TERMS
15. NUMBER OF PAGES
10
Ballistic tests
Fracture
Impact
Composites
Graphite/epoxy
Micrographs
16. PRICE CODE
Dynamic fracture
High-velocity impacts
17. SECURITY CLASSIFICATION
18. SECURITY CLASSIFICATION
19. SECURITY CLASSIFICATION
20. LIMITATION OF ABSTRACT
OF REPORT
OF THIS PAGE
OF ABSTRACT
UNCLASSIFIED
UNCLASSIFIED
UNCLASSIFIED
UL
Standard Form 298 (Rev. 2-89)
NSN 7540-01-280-5500
Prescribed by ANSI Std. Z39-18
298-102
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