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ASTM Selected Technical Papers
Composite Materials: Testing and Design (Eighth Conference)
By
JD Whitcomb
JD Whitcomb
1
NASA Langley Research Center
,
Hampton, VA 23665-5225
;
symposium chairman and editor
.
Search for other works by this author on:
ISBN-10:
0-8031-0980-6
ISBN:
978-0-8031-0980-3
No. of Pages:
476
Publisher:
ASTM International
Publication date:
1988

A closed-form approximate solution for the total strain energy release rate (G) of an elliptically shaped delamination has been developed from thin-film assumptions that treat the delamination as a clamped plate subject to enforced boundary displacements. Approximate equations are derived which couple the large deflection membrane stresses to the out-of-plane deflections. The model restricts the boundary to remain elliptical as the delamination grows. By applying the simple failure criterion that rapid growth of the delamination (which occurs when G reaches a critical value) precipitates the final failure of the laminate, the predicted failure stresses can be correlated with post-impact strength data available in the literature. The Mode I critical G is required for a good correlation, although the model calculates the total G averaged around the perimeter. For impact damage, data on delamination depth are rarely available. However, it was found that by assuming a delamination interface that results in the lowest failure strain, correlation with test data was obtained.

1.
Byers
,
A. B.
, “
Behavior of Damaged Graphite/Epoxy Laminates Under Compression Loading
,” NASA CR 159293,
National Aeronautics and Space Administration
,
Washington, DC
,
08
1980
.
2.
Guynn
,
E. G.
and
O'Brien
,
T. K.
, “
The Influence of Lay-Up and Thickness on Composite Impact Damage and Compression Strength
,”
AIAA Paper
No. 85-0646,
American Institute of Aeronautics and Astronautics
,
1985
.
3.
Williams
,
J. G.
, “
Effect of Damage and Open Holes on the Compression Strength of Tough Resin/High Strain Fiber Laminates
,”
NASA Technical Memorandum
 85756,
National Aeronautics and Space Administration
,
Washington, DC
,
02
1984
.
4.
Shuart
,
M. J.
and
Williams
,
J. G.
, “
Compression Failure Characteristics of ±45-Dominated Laminates with a Circular Holes or Impact Damage
,”
AIAA Paper
No. 84-0848,
American Institute of Aeronautics and Astronautics
,
05
1948
.
5.
Ramkumar
,
R. L.
, “
Environmental Effects on Composite Damage Criticality
,” NADC-79067-60,
Naval Air Development Center
,
01
1982
.
6.
Chai
,
H.
,
Babcock
,
C. D.
, and
Knauss
,
W. G.
, “
One-Dimensional Modelling of Failure in Laminated Plates by Delamination Buckling
,”
International Journal of Solids and Structures
 0020-7683, Vol.
17
, No.
11
,
1983
, pp. 1069-1083.
7.
Whitcomb
,
J. D.
, “
Analysis of Instability-Related Growth of a Through-Width Delamination
,”
NASA Technical Memorandum
 86301,
National Aeronautics and Space Administration
,
Washington, DC
,
09
1984
.
8.
Chai
,
H.
and
Babcock
,
C. D.
, “
Two-Dimensional Modelling of Compressive Failure in Delaminated Laminates
,”
Journal of Composite Materials
 0021-9983, Vol.
19
,
01
1985
, pp. 67-98.
9.
Yin
,
W. L.
and
Fei
,
Z.
, “
Delamination Buckling of Growth in a Clamped Circular Plate
,”
AIAA Paper
No. 85-0832,
American Institute of Aeronautics and Astronautics
.
10.
Yin
,
W. L.
, “
Axisymmetric Buckling and Growth of a Circular Delamination in a Compressed Laminate
,”
International Journal of Solids and Structures
 0020-7683, Vol.
21
, No.
5
,
1985
, pp. 503-514.
11.
Yin
,
W. L.
, “
Ultimate Axial Load Capacity of a Delaminated Plate
,”
AIAA Paper
No. 84-0892,
American Institute of Aeronautics and Astronautics
.
12.
Konishi
,
D.Y.
, “
Delamination Growth in Composite Structures Under Inplane Compression Loading
,”
Characterization, Analysis and Significance of Defects in Composite Materials
, AGARD-CP-3555,
Advisory Group for Aerospace Research and Development
,
04
1983
.
13.
Ramkumar
,
R. L.
, “
Composite Impact Damage Susceptibility
,” NADC-79068-60,
Naval Air Development Center
,
01
1981
.
14.
Williams
,
J. G.
,
O'Brien
,
T. K.
, and
Chapman
,
A. J.
, “
Comparison of Toughened Composite Laminates Using NASA Standard Damage Tolerance Tests
,”
NASA Conference Publication
 2321, ACEE Composite Structures Technology,
National Aeronautics and Space Administration
,
Washington, DC
,
08
1984
, pp. 51-73.
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