Multiple fatigue crack growth behavior has been studied in model transparent GFRP laminates. Detailed experimental observations have been made on the growth of individual fatigue cracks and on the evolution of cracks in off-axis layers in 0/90/±45S and ±45/90S laminates. Three stages of fatigue crack growth in the laminates have been identified: initiation, steady-state crack growth (SSCG), crack interaction and saturation. The results show that SSCG rate is essentially constant under constant load, independent of crack length and crack spacing. Finite element models have been developed and used to calculate the strain energy release rates associated with the off-axis matrix cracking. A correlation has been achieved between fatigue crack growth rates in off-axis layers and the total strain energy release rates.

1.
Talreja, R., 1994, “Fatigue of Composites,” Concise Encyclopaedia of Composite Materials, Kelly, A., ed., Pergamon, pp. 77–81.
2.
Highsmith, A. L., and Reifsnider, K. L., 1982, “Stiffness-reduction Mechanism in Composite Laminates,” Damage in Composite Materials, ASTM STP 775, pp. 103–117.
3.
Laws
,
N.
, and
Dvorak
,
G. J.
,
1988
, “
Progressive Transverse Cracking in Composite Laminates
,”
J. Comp. Mater.
,
23
, pp.
900
916
.
4.
McCartney
,
L. N.
,
1987
, “
Mechanics of Matrix Cracking in Brittle-Matrix Fibre-Reinforced Composites
,”
Proc. R. Soc. London
,
409
, pp.
329
350
.
5.
Nairn
,
J. A.
,
1989
, “
The Strain Energy Release Rate of Composite Microcracking: A Variational Approach
,”
J. Comp. Mater.
,
23
, pp.
1106
1129
.
6.
Talreja
,
R.
,
1985
, “
A Continuum Mechanics Characterization of Damage in Composite Materials
,”
Proc. R. Soc. London, Ser. A
,
399
, pp.
195
216
.
7.
Tong
,
J.
,
Smith
,
P. A.
,
Ogin
,
S. L.
, and
Guild
,
F. J.
,
1997
, “
On Matrix Crack Growth in Quasi-isotropic Laminates: I. Experimental Investigation
,”
Comput. Sci. Technol.
,
57
, pp.
1527
1536
.
8.
Boniface, L., Smith, P. A., Ogin, S. L., and Bader, M. G., 1987, “Observations on Transverse Ply Crack Growth in 02/902s CFRP Laminate under Monotonic and Cyclic Loading,” Proc. 2nd European Conference on Composite Materials, Vol. 3, London, pp. 156–165.
9.
Ogin
,
S. L.
,
Smith
,
P. A.
, and
Beaumont
,
P. W. R.
,
1985
, “
Matrix Cracking and Stiffness Reduction During Fatigue of a 0/90s GFRP Laminate
,”
Comput. Sci. Technol.
,
22
, pp.
23
31
.
10.
Boniface, L., Ogin, S. L., and Smith, P. A., 1991, “Fracture Mechanics Approaches to Transverse Ply Cracking in Composite Laminates,” Composite Materials: Fatigue and Fracture, ASTM STP 1110, O’Brien, T. K., ed., pp. 9–29.
11.
Boniface
,
L.
,
Ogin
,
S. L.
, and
Smith
,
P. A.
,
1991
, “
Strain Energy Release Rates and the Fatigue Growth of Matrix Cracks in Model Arrays in Composite Laminates
,”
Proc. R. Soc. London, Ser. A
,
432
, pp.
427
444
.
12.
Tong
,
J.
,
Guild
,
F. J.
,
Ogin
,
S. L.
, and
Smith
,
P. A.
,
1997
, “
Off-axis Fatigue Crack Growth and the Associated Energy Release Rate in Composite Laminates
,”
Appl. Comput. Mater.
,
4
, pp.
349
359
.
13.
Tong
,
J.
,
Smith
,
P. A.
,
Ogin
,
S. L.
, and
Guild
,
F. J.
,
1997
, “
On Matrix Crack Growth in Quasi-isotropic Laminates: II. Finite Element Analysis
,”
Comput. Sci. Technol.
,
57
, pp.
1537
1545
.
14.
Guild
,
F. J.
,
Ogin
,
S. L.
, and
Smith
,
P. A.
,
1993
, “
Modelling of 90° Ply Cracking in Cross Ply Laminates, Including Three Dimensional Effects
,”
J. Comp. Mater.
,
27
, pp.
646
667
.
You do not currently have access to this content.