Abstract
Critical crack tip stress intensity factor (K c) measurements were made for polyester resin reinforced with glass chopped strand mat (CSM) and woven roving fabric (WRF). Specimen thickness and initial crack length were varied for centre notched (CN) 100 mm wide▴ specimens. Some specimens were saturated by immersion in water under pressure. K c was negligibly affected by specimen thickness and it was concluded that plane strain conditions are not achieved in laminates of normal thickness. Scatter can be reduced by adjusting results to a standard glass content and K c varies continuously with crack length. The CSM experiments were extended to 915 mm wide specimens which failed at very low nett section stresses but there may be a region in which K c is roughly constant relative to crack length. In WRF specimens, however, it is the nett section stress which is constant at a value substantially below the UTS. Fatigue crack-growth studies were carried out on CN specimens. The Paris law adequately describes crack growth in CSM specimens at low rates of growth but Forman's law is better at high rates of growth. Neither law is valid for WRF material when dry but the behaviour changes after saturation with water. The crack-growth resistance of both materials is severely reduced by saturation with water.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
P. C. Paris and G. C. Sih, ASTM, STP 381, Philadelphia (1965) p. 30.
W. F. Brown and E. Srawley, ASTM, STP 410 (1966).
E. M. Wu and R. C. Reuter, University of Illinois, Department of Theoretical and Applied Mechanics, Report No. AD-613 576 (1963).
R. J. Sandford and R. Stonesifier, J. Comp. Mat. 5 (1971) 241.
P. W. R. Beaumont and D. C. Phillips, J. Mater. Sci. 7 (1972) 682.
Idem, J. Comp. Mater. 6 (1972) 32.
F. Mcgarry and J. F. Mandell, “Fracture Toughness Studies of Fibre Reinforced Plastic Laminates”, Faraday Special Discussions of the Chemical Society, 2 (1972).
R. Hamilton and C. Berg, Fibre Sci. Technol. 6 (1973) 55.
M. J. Owen and P. T. Bishop, J. Comp. Mater. 7 (1973) 146.
M. J. Owen and R. G. Rose, J. Phys. D. Appl Phys. 6 (1973) 42.
A. Holdsworth, S. Morris and M. J. Owen, ibid 7 (1974) 2036.
J. F. Mandell, F. J. Mcgarry, S. S. Wang and J. Im, J. Comp. Mater. 8 (1974) 106.
A. W. Holdsworth, Ph.D. Thesis, University of Nottingham (1973).
S. Gagar and L. J. Broutman, Int. J. Fracture 10 (1974) 606.
J. T. Barnby and B. Spencer, J. Mater. Sci. 11 (1976) 78.
N. Fried, J. Kaminetsby and M. Silvergleit, “The Effect of Deep Submergence Operational Conditions on Filament Wound Plastics”, 21st Annual Conf. Soc. of Plastics Industries Reinforced Plastics Division (1966).
R. C. Wyatt and K. H. G. Ashbee, Fibre Sci. Technol. 2 (1969–70) 29.
J. B. Romans, A. G. Sands and J. E. Cowling, Ind. Eng. Chem. Product Res. Devel. 11 (1972) 261.
P. C. Paris, Boeing Co. Document No. D-17867, Addendum N (1957).
R. W. Hertzberg, J. A. Manson and H. Nordberg, Ohio State University Report No. AD-700434 (1963).
G. C. Sih, P. D. Hilton and R. P. Wei, Report No. AD-709 214 (1970).
P. A. Thornton, J. Comp. Mater. 6 (1972) 147.
M. J. Owen and P. T. Bishop, J. Phys. D. Appl. Phys. 7 (1974) 1214.
R. J. Cann, Ph.D. Thesis, University of Nottingham, (1977).
M. J. Owen, Trans. J. Plastics Inst. 35 (1967) 353.
R. G. Forman, V. E. Kearny and P. M. Engle, J. Basic Eng. 89 (1967) 459.
J. V. Walters, Ph.D. Thesis, University of Nottingham (1975).
G. Smith, A. K. Green and W. H. Bowyer, Proceedings of the Institute of Physics Stress Analysis Group, Annual Conference, Sheffield (1976) “Fracture Mechanics in Engineering Practice” (Applied Science, London, 1977) p. 271.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Owen, M.J., Cann, R.J. Fracture toughness and crack-growth measurements in GRP. J Mater Sci 14, 1982–1996 (1979). https://doi.org/10.1007/BF00551041
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00551041