Abstract
Damage evolution in fatigue tests (R = 0.5, −1, 2) conducted on carbon fiber reinforced plastic (CFRP) composites has been characterized using digital image correlation (DIC). Since damage initiation/delamination is a local phenomenon affecting transverse strain more than the longitudinal, local transverse strain is a better indicator of onset of delamination and its propagation. Variation of transverse strain near the initiated delamination with cycles indicates that the damage evolution occurs over 2–3 stages. Each stage has a stable damage growth with sudden increase between the stages. Waviness and the associated error due to the lag between image and load data acquisition was overcome by plotting the maximum transverse strain obtained from a curve fit to each set of continuous cycles. Error due to large relative deformations was avoided by choosing different reference images for different stages. Extent of damage zone and its evolution was characterized by the length over which the transverse strain exceeds a limiting value, which was taken to be that at the end of first stage in the plot. Rate at which the damage propagates shows similar variation as that of the local transverse strain, which shows that the latter can be used as an indicator of fatigue damage evolution. This also provides a method to quantify the damage in terms of local transverse strain, which can in turn be used to validate any developed damage models.
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Abbreviations
- σx :
-
Longitudinal stress
- ϵy :
-
Transverse strain
- σmax :
-
Maximum stress
- Δϵ:
-
Longitudinal strain range
- Δσ:
-
Longitudinal stress range
References
Bhat, M.R., Murthy, C.R.L.: Fatigue damage stages in unidirectional glass-fibre-epoxy composites: identification through acoustic emission technique. Int. J. Fatigue 5, 401–405 (1993)
Jones, R.M.: Mechanics of Composite Materials, 2nd edn. Taylor & Francis, Philadelphia (1999)
Reifsnider, K.L., Case, S.W.: Damage Tolerance and Durability of Material Systems. Wiley, New York (2002)
Bourchak, M., Farrow, I.R., Bond, I.P., Rowland, C.W., Menan, F.: Acoustic emission energy as a fatigue damage parameter for CFRP composites. Int. J. Fatigue 29, 457–470 (2007)
Smith, P.A., Wood, J.R.: Poisson’s ratio as a damage parameter in the static tensile loading of simple crossply laminates. Compos. Sci. Technol. 38, 85–93 (1990)
Surgeon, M., Vanswijgenhoven, E., Wevers, M., Van Der Biest, O.: Transverse cracking and Poisson’s ratio reduction in cross-ply carbon fibre-reinforced polymers. J. Mater. Sci. 34, 5513–5517 (1999)
Van Paepegem, W., De Baere, I., Lamkanfi, E., Degrieck, J.: Poisson’s ratio as a sensitive indicator of (fatigue) damage in fibre-reinforced plastic. Fatigue Fract. Eng. Mater. Struct. 30, 269–276 (2007)
Sutton, M.A., Orteu, J.-J., Schreier, H.W.: Image Correlation for Shape, Motion and Deformation Measurements. Springer, New York (2009)
Khaja Mohiddin, S.M., Subramanian, S.J., Murthy, H.: Study of damage evolution during fatigue of composites using DIC. Proceedings of SEM XII International Congress and Exposition on Experimental and Applied Mechanics Conference, Costa Mesa, USA, CD-ROM (2012)
Acknowledgments
The authors gratefully acknowledge National Aerospace Laboratories, Bangalore for the fabrication of the tested specimens.
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© 2017 The Society for Experimental Mechanics, Inc.
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Murthy, H., Venkatachalam, S. (2017). Characterization of Fatigue Induced Damage Evolution in CFRPs Using DIC. In: Zehnder, A., et al. Fracture, Fatigue, Failure and Damage Evolution, Volume 8. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-42195-7_11
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DOI: https://doi.org/10.1007/978-3-319-42195-7_11
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