In this paper, an experimental investigation on interlaminar fracture behavior and fracture toughness of a graphite/epoxy multidirectional composite laminate is presented using end-notched flexure specimens. The 0/θ interfaces are considered. The interlaminar fracture toughness is obtained and compared using three data reduction methods, i.e., the area method, classical laminated plate theory, and finite element analysis. Results show that the toughness value depends on the data reduction method used. Two different crack-length-to-span ratios are chosen to study how the stable or unstable crack extension influences the toughness measurement. It is observed that the toughness obtained from the tests of stable crack extension is appreciably higher than that from the tests of unstable crack extension. It is also seen that friction resulting from contact of crack surfaces greatly affects the measured toughness in the case of stable crack extension. In addition, effects of the specimen geometry and fiber orientation on the interlaminar fracture toughness are also evaluated. [S0094-4289(00)02804-8]
1.
Russell, A. J., and Street, K. N., 1982, “Factors Affecting the Interlaminar Fracture Energy of Graphite/Epoxy Laminates,” Progress in Science and Engineering of Composites, ICCM-IV, Hayashi, T., Kawata, K., and Umekawa, S., eds., Tokyo, pp. 279–286.
2.
Carlsson
, L. A.
, Gillespie
, J. W.
, and Pipes
, R. B.
, 1986
, “On the Analysis and Design of the End-Notched Flexure (ENF) Specimen for Mode II Testing
,” J. Compos. Mater.
, 20
, pp. 594
–604
.3.
Carlsson, L. A., and Gillespie, J. W., 1989, “Mode II Interlaminar Fracture of Composites,” Application of Fracture Mechanics to Composite Materials, Friedrich, K., ed., Elsevier Science, pp. 113–157.
4.
Chatterjee
, S. N.
, 1991
, “Analysis of Test Specimens for Interlaminar Mode II Fracture Toughness, Part 1. Elastic Laminates
,” J. Compos. Mater.
, 25
, pp. 470
–493
.5.
Kageyama, K., Kikuchi, M., and Yanagisawa, N., 1991, “Stabilized End Notched Flexure Test: Characterization of Mode II Interlaminar Crack Growth,” Composite Materials: Fatigue and Fracture, 3rd Volume, ASTM STP 1110, O’Brien, T. K., ed., pp. 210–225.
6.
Cairns
, D. S.
, 1992
, “Static and Dynamic Mode II Strain Energy Release Rates in Toughened Thermosetting Composite Laminates
,” J. Compos. Technol. Res.
, 14
, pp. 37
–42
.7.
Davidson, B. D., Fariello, P. L., Hudson, R. C., and Sundararaman, V., 1997, “Accuracy Assessment of the Singular-Field Based on Mode-Mix Decomposition Procedure for the Prediction of Delamination,” Composite Materials: Testing and Design, 13th Volume, ASTM STP 1242, Hooper, S. J., ed., pp. 109–128.
8.
Wilkins, D. J., Eisenmann, J. R., Camin, R. A., Margolis, W. S., and Benson, R. A., 1982, “Characterizing Delamination Growth in Graphite-Epoxy,” Damage in Composite Materials: Basic Mechanisms, Accumulation, Tolerance, and Characterization, ASTM STP 775, Reifsnider, K. L., ed., pp. 168–183.
9.
Sun
, C. T.
, and Jih
, C. J.
, 1987
, “On Strain Energy Release Rate for Interfacial Cracks in Bimaterial Media
,” Eng. Fract. Mech.
, 28
, pp. 13
–20
.10.
Chai
, H.
, 1990
, “Interlaminar Shear Fracture of Laminated Composites
,” Int. J. Fract.
, 43
, pp. 117
–131
.11.
Chou, I., Kimpara, I., Kageyama, K., and Ohsawa, I., 1995, “Mode I and Mode II Fracture Toughness Measured between Differently Oriented Plies in Graphite/Epoxy Composites,” Composite Materials: Fatigue and Fracture, 5th Volume, ASTM STP 1230, Martin, R. H., ed., pp. 132–151.
12.
Hudson
, R. H.
, Davidson
, B. D.
, and Polaha
, J. J.
, 1998
, “Effect of Remote Ply Orientation on the Perceived Mode I and Mode II Toughness of θ/θ and θ/−θ Interfaces
,” Appl. Compos. Mater.
, 5
, pp. 123
–138
.13.
Choi
, N. S.
, Kinloch
, A. J.
, and Williams
, J. G.
, 1999
, “Delamination Fracture of Multidirectional Carbon-Fiber/Epoxy Composites under Mode I, Mode II and Mixed-Mode I/II Loading
,” J. Compos. Mater.
, 33
, pp. 73
–100
.14.
Davison
, B. D.
, and Sundararaman
, V.
, 1996
, “A Single Leg Bending Test for Interfacial Fracture Toughness Determination
,” Int. J. Fract.
, 78
, pp. 193
–210
.15.
Polaha
, J. J.
, Davidson
, B. D.
, Hudson
, R. C.
, and Pieracci
, A.
, 1996
, “Effects of Mode Ratio, Ply Orientation and Precracking on the Delamination Toughness of a Laminated Composite
,” J. Reinf. Plast. Compos.
, 15
, pp. 141
–173
.16.
Sundararaman
, V.
, and Davidson
, B. D.
, 1997
, “An Unsymmetric Double Cantilever Beam Test for Interfacial Fracture Toughness Determination
,” Int. J. Solids Struct.
, 34
, pp. 799
–817
.17.
Trakas, K., and Kortschot, M. T., 1997, “The Relationship between Critical Strain Energy Release Rate and Fracture Mode in Multidirectional Carbon-Fiber/Epoxy Laminates,” Composite Materials: Fatigue and Fracture, 6th Volume, ASTM STP 1285, Armanios, E. A., ed., pp. 283–304.
18.
Foster
, S.
, Robinson
, P.
, and Hodgkinson
, J. M.
, 1997
, “Interlaminar Fracture Toughness Testing of 0 deg/θ deg Intefaces in Carbon-Epoxy Laminates Using Edge Delaminated Strategy
,” Plast. Rubber Compos. Proces. Appl.
, 26
, pp. 430
–437
.19.
Tao
, J.
, and Sun
, C. T.
, 1998
, “Influence of Ply Orientation on Delamination in Composite Laminates
,” J. Compos. Mater.
, 32
, pp. 1933
–1947
.20.
Sun
, C. T.
, and Zheng
, S.
, 1996
, “Delamination Characteristics of Double-Cantilever Beam and End-Notched Flexure Composite Specimens
,” Compos. Sci. Technol.
, 56
, pp. 451
–459
.21.
Davidson
, B. D.
, 1990
, “An Analytical Investigation of Delamination Front Curvature in Double Cantilever Beam Specimens
,” J. Compos. Mater.
, 24
, pp. 1124
–1137
.22.
Gibson, R. F., 1994, Principles of Composite Material Mechanics, McGraw-Hill, New York.
23.
Carlsson, L. A., and Pipes, R. B., 1987, Experimental Characterization of Advanced Composite Materials, Prentice-Hall, NJ.
24.
Rybicki
, E. F.
, and Kanninen
, M. F.
, 1977
, “A Finite Element Calculation of Stress Intensity Factors by a Modified Crack Closure Integral
,” Eng. Fract. Mech.
, 9
, pp. 931
–938
.25.
Sun
, C. T.
, and Jih
, C. J.
, 1987
, “On Strain Energy Release Rates for Interfacial Cracks in Bimaterial Media
,” Eng. Fract. Mech.
, 28
, pp. 13
–20
.26.
Hibbitt, Karlsson, and Sorensen, Inc., 1998, ABAQUS/Standard, Version 5.8.
27.
Carlsson
, L. A.
, Gillespie
, J. W.
, and Trethewey
, B. R.
, 1986
, “Mode II Interlaminar Fracture of Graphite/Epoxy and Graphite/PEEK
,” J. Reinf. Plast. Compos.
, 5
, pp. 170
–187
.Copyright © 2000
by ASME
You do not currently have access to this content.
