Abstract
Three analytical-experimental hybrid approaches for determining the range of stress intensity factors (SIF) and the pseudo-SIFs of fatigue cracks on the presence of crack closure, crack tip plasticity and blunting are presented and evaluated. These approaches use the Digital Image Correlation (DIC) technique to measure cyclic-varying displacement fields near the crack tip. The first uses displacement data of points located on the cracked component surface near and along the crack faces, finding the parallel and orthogonal displacements of symmetrical points with relation to the crack faces to determine the crack opening displacements (COD), which are placed in the crack displacement field equations to obtain the SIF values. The second determines coefficients of generalized Westergaard displacement field functions by an over-deterministic nonlinear Least Square scheme that allows the accurate localization of the crack tip coordinates. The third computes the J-integral along an arbitrary but elastic contour path placed around the crack tip to determine the SIF, using experimentally determined displacement gradients, the calculated stresses and the calculated energy densities for points along the path. The three approaches are applied to the case of cracks propagating in disk-shaped compact-tension DC(T) specimens subjected to mode I cyclic loads, considering the non-linear effects mentioned above.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Sutton, M.A., McNeill, S.R., Helm, J.D., Chao, Y.J.: Advances in Two-Dimensional and Three-Dimensional Computer Vision, Photomechanics, pp. 323–372. Springer, Berlin (2000)
Sutton, M.A., Orteu, J.J., Schreier, H.: Image Correlation for Shape, Motion and Deformation Measurements: Basic Concepts, Theory and Applications. Springer, New York (2009)
McNeill, S., Peters, W., Sutton, M.: Estimation of stress intensity factor by digital image correlation. Eng. Fract. Mech. 28(1), 101–112 (1987)
Rethore, J., Gravouil, A., Morestin, F., Combescure, A.: Estimation of mixed-mode stress intensity factors using digital image correlation and an interaction integral. Int. J. Fract. 132(1), 65–79 (2005)
Yoneyama, S., Morimoto, Y., Takashi, M.: Automatic evaluation of mixed-mode stress intensity factors utilizing digital image correlation. Strain 42(1), 21–29 (2006)
Ju, S.-H., Liu, S., Liu, K.: Measurement of stress intensity factors by digital camera. Int. J. Solids Struct. 43(5), 1009–1022 (2006)
Lopez-Crespo, P., Shterenlikht, A., Patterson, E., Yates, J., Withers, P.: The stress intensity of mixed mode cracks determined by digital image correlation. J. Strain Anal. Eng. Des. 43(8), 769–780 (2008)
Zhang, R., He, L.: Measurement of mixed-mode stress intensity factors using digital image correlation method. Opt. Lasers Eng. 50(7), 1001–1007 (2012)
Becker, T., Mostafavi, M., Tait, R., Marrow, T.: An approach to calculate the J-integral by digital image correlation displacement field measurement. Fatigue Fract. Eng. Mater. Struct. 35(10), 971–984 (2012)
Harilal, R., Vyasarayani, C., Ramji, M.: A linear least squares approach for evaluation of crack tip stress field parameters using DIC. Opt. Lasers Eng. 75, 95–102 (2015)
Sanford, R.J.: Principles of Fracture Mechanics. Pearson College Division (2003)
Atluri, S.N., Kobayashi, A.: Chapter 1, Mechanical responses of material, Handbook on experimental mechanics, pp. 1–40 (1987)
Rice, J.R.: A path independent integral and the approximate analysis of strain concentration by notches and cracks. J. Appl. Mech. 35(2), 379–386 (1968)
ANSYS online manual, Structural Analysis Guide. http://www.ansys.stuba.sk/html/guide_55/g-str/GSTR10.htm
Correlated Solutions Inc., U. S. A. http://www.correlatedsolutions.com/
Elber, W.: The Significance of Fatigue Crack Closure, Damage Tolerance in Aircraft Structures. ASTM International, West Conshohocken (1971)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 The Society for Experimental Mechanics, Inc.
About this paper
Cite this paper
Gonzáles, G.L.G., Diaz, J.G., González, J.A.O., Castro, J.T.P., Freire, J.L.F. (2017). Determining SIFs Using DIC Considering Crack Closure and Blunting. In: Zhu, Y., Zehnder, A. (eds) Experimental and Applied Mechanics, Volume 4. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-42028-8_4
Download citation
DOI: https://doi.org/10.1007/978-3-319-42028-8_4
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-42027-1
Online ISBN: 978-3-319-42028-8
eBook Packages: EngineeringEngineering (R0)