EXPERIMENTAL INVESTIGATION OF THE MICROSCOPIC DAMAGE DEVELOPMENT AT MODE I FATIGUE DELAMINATION TIPS IN CARBON/EPOXY LAMINATES

Authors

  • Rafiullah Khan Department of Mechanical Engineering, International Islamic University, Islamabad, Pakistan
  • Rene Alderliesten Faculty of Aerospace Engineering, Technical University Delft, Netherland
  • Saeed Badshah Department of Mechanical Engineering, International Islamic University, Islamabad, Pakistan
  • M. A. Khattak Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
  • M. S. Khan Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
  • Rinze Benedictus Faculty of Aerospace Engineering, Technical University Delft, Netherland

DOI:

https://doi.org/10.11113/.v78.8072

Keywords:

Delamination, Stress ratio effect, Fractography, micro-cracks

Abstract

This paper investigates the damage development ahead of mode I delamination tips in carbon /epoxy laminates using scanning electron microscope (SEM). Two techniques were adopted for the investigation; the first technique consisted of the application of stepwise load increments on DCB (double cantilever beam) specimens inside the SEM, while images were recorded until delamination onset. For the second technique, the DCB specimens were fatigue tested under different combinations of monotonic and cyclic loading. After the fatigue tests, the specimens were kept open in the microscope by insertion of steel wedges allowing the inspection of the delamination tips. The investigation revealed that multiple micro-cracks are formed parallel to the delamination growth direction ahead of the tip that coalesces. Micro-cracks that were formed 2 or 3 plies away from the delamination plane were observed to cause fibre bridging. 

Author Biography

  • M. A. Khattak, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia

    Dr. Muhammad Adil Khattak
    (PhD,ME,MBA,BE)

    Faculty of Mechanical Engineering
    Universiti Teknologi Malaysia
    81310 UTM Skudai, Johor, MALAYSIA

    Mobile +6017 8272871 / Office +607 5534 856 / Fax +607 5566 159

References

Khan, R. 2013. Delamination Growth in Composites under fatigue. PhD Thesis. TU Delft Netherland.

Harris, B. 2003. Fatigue in Composites. Science and Technology of the Fatigue Response of Fiber Reinforced Plastics. Cambridge: Woodhead Publishing Ltd.

Ritchie, R. O. 1988. Mechanisms of Fatigue Crack Propagation in Metals, Ceramics and Composites: Role of Crack Tip Shielding. Materials Science and Engineering A. 103(1): 15-28.

Greenhalgh and Emile. 2009. Failure Analysis and Fractography of Polymer Composites. Elsevier: Woodhead Publishing Limited.

Bradley, W. L. and Cohen, R. N. 1985. Matrix Deformation and Fracture in Graphite-Reinforced Epoxies. In Delamination and Debonding of Materials. ASTM International STP. 876: 389-410.

Sue, H. J., Jones, R. E., and Garcia Meitin, E. I. 1993. Fracture Behavior of Model Toughened Composites under Mode I and Mode II Delamination. Journal of Materials Science. 28(23): 6381-6391.

Coats, T. W., and Harris, C. E. 1999. A Progressive Damage Methodology for Residual Strength Predictions of Notched Composite Panels. Journal of Composite Materials. 33(23): 2193-2224.

Rogers, C. E., Greenhalgh, E. S., and Robinson, P. 2008. Developing a Mode II Fracture Model for Composite Laminates. ECCM13.

Tanaka, K., and Tanaka, H. 1997. Stress-ratio Effect on Mode II Propagation of Inter-laminar Fatigue Cracks in Graphite/epoxy Composites. Composite Materials: Fatigue and Fracture. ASTM. 1285: 16.

Inglis, G. R. 1957. Analysis of Stresses and Strains near the End of a Crack Traversing a Plate. Journal of Applied Mechanics. 24: 361-364.

Irwin, G. R. 1985. Fracture Handbuch der physik VI. S. Flugge New York: Springer-Verlag.

Khan, R., Alderliesten, R. and Benedictus, R. 2014. Two-Parameter Model For Delamination Growth Under Mode I Fatigue Loading (Part B: Model Development). Composites Part A: Applied Science and Manufacturing. 65: 201-210.

Khan, R., Alderliesten, R. and Benedictus, R. 2014. Two-Parameter Model for Delamination Growth under Mode I Fatigue Loading (Part A: Experimental study). Composites Part A: Applied Science and Manufacturing. 65: 192-200.

Khan, R., Alderliesten, R., Yao, L. and Benedictus, R. 2014. Crack closure and Fibre Bridging during Delamination Growth in Carbon Fibre/Epoxy Laminates under Mode I Fatigue Loading. Composites Part A: Applied Science and Manufacturing. 67: 201-211.

Rodi, R.2012. The Residual Strength Failure Sequence In Fiber Metal Laminates. PhD Thesis, Aerospace Faculty Tu Delft Nederland.

ASTM. 2007. Standard Test Method for Mode I Interlaminar Fracture Toughness Of Unidirectional Fiber-Reinforced Polymer Matrix Composites. D5528-01

Rans, C. D., Alderliesten R. and Benedictus R. 2011. Misinterpreting The Results: How Similitude Can Improve Our Understanding Of Fatigue Delamination Growth. Composite Science and Technology. 71: 230-238.

Lee, S. M. 1997. Mode II Delamination Failure Mechanisms of Polymer Matrix Composites. Journal of Material Science. 32: 1287-1295.

Bascom, W. D., Boll, D. J., Hunstun, D. L., Fuller, B. and Phillips P. J. 1987. Fractographic Analysis of Interlaminar Fracture. Toughned Composites. ASTM STP. 937: 131-149.

Hojo, M., Tanaka,K., Gustafson, C-G. and Hayashi R. 1987. Effect of Stress Ratio on Near-Threshold Propagation of Delamination Fatigue Cracks in Unidirectional CFRP. Composites Science and Technology. 29(4): 273-292.

Pascoe, J. A., Alderliesten, R. C. and Benedictus, R. 2015. On the Relationship between Disbond Growth and the Release of Strain Energy. Engineering Fracture Mechanics. 133: 1-13.

Yao, L., Alderliesten, R., Zhao, M. and Benedictus, R. 2014. Discussion on the Use of the Strain Energy Release Rate for Fatigue Delamination Characterization. Composites: Part A. 66: 65-72.

Downloads

Published

2016-10-31

Issue

Section

Science and Engineering

How to Cite

EXPERIMENTAL INVESTIGATION OF THE MICROSCOPIC DAMAGE DEVELOPMENT AT MODE I FATIGUE DELAMINATION TIPS IN CARBON/EPOXY LAMINATES. (2016). Jurnal Teknologi, 78(11). https://doi.org/10.11113/.v78.8072