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ASTM Selected Technical Papers
Composite Materials: Testing and Design (Tenth Volume)
By
GC Grimes
GC Grimes
1
Chairman and Editor
, 10th Symposium on Composite Materials: Testing and Design
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ISBN-10:
0-8031-1426-5
ISBN:
978-0-8031-1426-5
No. of Pages:
479
Publisher:
ASTM International
Publication date:
1992

Delamination failure in a unidirectional curved composite laminate was investigated. The curved laminate failed unstably by delaminations developing around the curved region of the laminate at different depths through the thickness until virtually all bending stiffness was lost. Delamination was assumed to initiate at the location of the highest radial stress in the curved region. A closed form curved beam elasticity solution and a two-dimensional finite element analysis (FEA) were conducted to determine this location. The variation in the strain energy release rate, G, with delamination growth was determined using the FEA. A strength-based failure criterion adequately predicted the interlaminar tension failure that caused initial delamination onset. Using the G analysis, the delamination was predicted to extend into the arm and leg of the laminate, predominantly in Mode I. As the initial delamination grew around the curved region, the maximum radial stress in the newly formed inner sublaminate increased to a level sufficient to cause a new delamination to initiate in the sublaminate with no increase in applied load. This failure progression was observed experimentally.

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,
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Wilkins
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American Society for Testing and Materials
,
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,
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,
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, Ed.,
American Society for Testing and Materials
,
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,
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.
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,
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,
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,
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, and
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, “
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Mabson
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and
Neall
,
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, III
, “
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11.
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12.
O'Brien
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,
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,
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,
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, and
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,”
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, No.
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,
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14.
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,
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, and
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,” in
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, ASTM STP 1110,
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, Ed.,
American Society for Testing and Materials
,
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,
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15.
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, and
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,
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16.
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,
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and
Murri
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, “
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,” in
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, ASTM STP 1059,
Garbo
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, Ed.,
American Society for Testing and Materials
,
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,
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, pp. 251–270.
17.
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,
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, “
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,
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,
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, pp. 688–700.
18.
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,
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and
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,
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, “
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,” in
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,
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,
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,
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,
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, and
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,” in
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, ASTM STP 1110,
O'Brien
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, Ed.,
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,
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,
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20.
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21.
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,
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,
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22.
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23.
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,
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and
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, “
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,”
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, Vol.
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,
1977
, pp. 931–938.
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