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Abstract

Woven fabric composites with a thermoplastic matrix form a class of promising materials for industrial use, due to their balance of properties. They combine excellent mechanical performance with ease of processing.

Failure behavior of notched woven fabric composites shows a number of peculiarities, the most notorious being the dependence of notched tensile strength on notch radius below a certain hole size. This dependence, which is observed for all fiber reinforced composites, has been modelled by other authors with the aid of semi-empirical continuum mechanics models. If at all based on physical principles, the modelled fracture process rarely coincides with experimentally observed failure phenomena.

This study investigates failure of notched woven fabric (0-90)4, E-glass laminates with a PETP matrix.

A model is proposed which is, unlike other previous modelling efforts, related to experimentally observed fracture phenomena. It introduces the ineffective length of a critical element in the notch root, obtained by a simple shear lag-type analysis. The notched strength is shown to depend on the ratio of notch radius to the critical element ineffective length. The model is able to predict changes in notched strength with composite parameters like fiber volume fraction, fiber bundle diameter and interfacial or matrix shear strength, and takes into account the composite microstructure.

Keywords

composites woven fabric notched strength PETP thermoplastic critical element shear lag analysis size effect

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References

1. Waddoups, M. E. , J. R. Eisenmann and B. E. Kaminski . 1971. "Macroscopic Fracture Mechanics of Advanced Composite Materials," Journal of Composite Materials, 5:446.

2. Whitney, J. M. and R. J. Nuismer . 1974. "Stress Fracture Criteria for Laminated Composites Containing Stress Concentration," Journal of Composite Materials, 8:253.

3. Pipes, R. B. , R. C. Wetherhold and J. W. Gillespie, Jr. 1979. "Notched Strength of Composite Materials," Journal of Composite Materials, 13:148.

4. Lo, K. H. , E. M. Wu and D. Y. Konishi . 1983. "Failure Strength of Notched Composite Materials," Journal of Composite Materials, 17:384.

5. Backlund, J. and C. G. Aronsson . 1986. "Tensile Fracture of Laminates with Holes," Journal of Composite Materials, 20:259.

6. Chang, L. W. , S. S. Yau and T. W. Chou . 1987. "Notched Strength of Woven Fabric Composites with Moulded-In Holes," Composites, 18(3):233.

7. Tan, S. C. 1987. "Notched Strength Prediction and Design of Laminated Composites under In-Plane Loadings," Journal of Composite Materials, 21:750.

8. Tan, S. C. 1988. "Finite-Width Correction Factors for Anisotropic Plate Containing a Central Opening," Journal of Composite Materials, 22:1080.

9. Naik, N. K. , P. S. Shembekar and M. K. Verma . 1990. "On the Influence of Stacking Sequence on Notch Sensitivity of Fabric Laminates," Journal of Composite Materials, 24:838.

10.

10. Naik, N. K. , P. S. Shembekar and M. V. Hosur . 1991. "Failure Behavior of Woven Fabric Composites," Journal of Composite Technology & Research, 13(1):107.

11.

11. Shembekar, P. S. and N. K. Naik . 1992. "Notched Strength of Fabric Laminates. II: Effect of Stacking Sequence," Composites Science & Technology, 44:13.

12.

12. Shembekar, P. S. and N. K. Naik . 1992. "Notched Strength of Fabric Laminates. I: Prediction," Composites Science & Technology, 44:1.

13.

13. Neuber, H. 1961. "Theory of Stress Concentration for Shear-Strained Prismatical Bodies with Arbitrary Nonlinear Stress-Strain Law," Journal of Applied Mechanics, 12:544.

14.

14. Peterson, R. E. 1962. Stress Concentration Design Factors, Third Edition. New York-London: John Wiley & Sons.

15.

15. Weixing, Y. 1992. "On the Notched Strength of Composite Laminates," Composites Science & Technology, 45:105.

16.

16. Karlak, R. F. 1977. "Hole Effects in a Related Series of Symmetrical Laminates," Proceedings of Failure Modes in Composites III, American Society of Metals, Chicago.

17.

17. Kelly, A. Strong Solids, Second Edition. Oxford: Clarendon Press.

18.

18. Marissen, R. , H. H. Hornman , L. E. P. Wenmakers and K. Scholle . 1990. "Advanced Thermoplastic Composites for Low Cost Structural Applications," Proceedings of SAMPE '90, Basel, May 29-31.

19.

19. Marissen, R. , H. H. Hornman , L. E. P. Wenmakers , L. M. J. Robroek and W. D. Brouwer . 1991. "Processing of Continuous Fibre Reinforced Thermoplastic Composites for Multi-Purpose Engineering," Proceedings of Verbundwerk 91, Wiesbaden, October 9-11.

20.

20. Luke, M. , K. Schulte and H. Nowack . 1993. "Monotonic and Cyclic Behavior of Notched CFRP-Components and Prediction," Proceedings of Fatigue 93, Montreal (May).

Notched Strength of Thermoplastic Woven Fabric Composites

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