Abstract

The instrumented drop weight impact test has been used to study the relative impact damage tolerance of Kevlar®-49 and Kevlar-29 aramid fibers, Thornel®-300 graphite fiber, and E-glass as reinforcements in epoxy-matrix composite materials. Under the conditions of the test, the energy absorbed to failure, defined as the first through crack or the maximum of the load-displacement trace, is proportional to the tensile strain energy to failure of the reinforcing fiber. Thus, the Kevlar fibers, and in particular Kevlar 29, absorb significantly more energy than Thornel 300, while E-glass is intermediate between the two Kevlar fibers. Hybrids with Kevlar 49 and Thornel 300 also absorb more total energy than do all graphite.

References

1.
Ireland
,
D. R.
, “
Procedures and Problems Associated with Reliable Control of the Instrumented Impact Test
” in
Instrumented Impact Testing
, STP 563,
American Society for Testing and Materials
,
Philadelphia
1974
, pp.
3
-
29
.
2.
Miller
,
A. G.
,
Hertzberg
,
P. E.
, and
Rantula
,
V. W.
, “
Toughness Testing of Composite Materials
,”
Society of Aerospace Materials and Process Engineers Quarterly
, Vol.
12
, No.
2
,
01
1981
, pp.
36
-
42
.
3.
Dorey
,
G.
,
Sidey
,
G. R.
, and
Hutchings
,
J.
, “
Impact Properties of Carbon Fibre/Kevlar® 49 Fibre Hybrid Composites
,”
Composites
 0010-4361, Vol.
9
, No.
1
,
01
1978
, pp.
25
-
32
.
4.
Riewald
,
P. G.
and
Zweben
,
C.
, “
Kevlar® 49 Hybrid Composites for Commercial and Aerospace Applications
,”
30th Annual Technical Conference
,
The Society of the Plastics Industry
,
1975
, Section 14-B, pp.
1
-
10
.
5.
Beaumont
,
P. W. R.
,
Riewald
,
P. G.
, and
Zweben
,
C.
, “
Methods for Improving the Impact Resistance of Composite Materials
” in
Foreign Object Impact Damage to Composites
, STP 568,
American Society for Testing and Materials
,
Philadelphia
, pp.
134
-
150
.
6.
Rhodes
,
M. D.
, “
Impact Tests on Fibrous Composite Sandwich Structures
,”
NASA Technical Memorandum
 78719,
National Aeronautics and Space Administration
,
10
1978
.
7.
Harding
,
D. G.
and
Griffith
,
Y. M.
, “
Composite Design Technology for Light Helicopter Airframes
,”
Fifth DOD Conference on Fibrous Composites in Structural Design
,
Naval Air Development Center
,
Warminster, PA
,
01
1981
.
8.
Zweben
,
C.
, “
Fracture of Kevlar® 49, E-Glass and Graphite Composites
,”
ASTM Symposium on Fracture Mechanics of Composites
,
American Society for Testing and Materials
,
Philadelphia
,
1974
.
9.
Rotem
,
A.
and
Litshitz
,
J. M.
, “
Longitudinal Strength of Unidirectional Fibrous Composite under High Rate Loading
,”
26th Annual Technical Conference
, Section 10-G,
The Society of the Plastics Industry
,
1971
, pp.
1
-
10
.
10.
Coppa
,
A. P.
,
Zweben
,
C.
, and
Mirandy
,
L.
, “
Flywheel Containment Technology Assessment
,” UCRL-15261,
Lawrence Livermore Laboratory
,
Livermore, CA
,
07
1981
.
This content is only available via PDF.
You do not currently have access to this content.