In engineering industries, the usage of composites made of thin anisotropic layers is being increased rapidly. Most of the convention analysis generally neglects the presence very thin adhesive material due to complicated modeling of thin layers; however, it leads to failure in providing reliable assessment of the potential debonding which usually caused by the fracture of the adhesive layer. This study presents the interlaminar stresses in thin layered anisotropic composites and the patch repair analysis of the composites by the Boundary Element Method (BEM). Thin adhesive layer has also been taken into account for the BEM modeling. the current work applies the already existed self-regularization scheme which was presented by Y.C Shiah to analyze thin anisotropic composites and the stress concentration factor (SCF) has compared for cases of with the presence of the adhesive layer and without the adhesive layer. Few benchmark examples of the patch repair of the plate with a hole containing adhesive layer and without containing of the adhesive layer are analyzed to study the Stress Concentration Factor by the Boundary Element Method approach.

1. He, M.G.; Tan, C.L. (2013): A self-regularization technique in boundary element method for 3-D stress Analysis. CMES- Computer Modeling in Engineering and Sciences, vol.95, no.4, pp.317-349, 2013.
2. Shiah, Y. C., Tan, C. L., & Chan, L. D. (2015). Boundary Element Analysis of Thin Anisotropic Structures by a Self-regularization Scheme. CMES: Computer Modeling in Engineering & Sciences, 109(1), 15-33.
3. Granados, J.J.; Gallego, R. (2001): Regularization of Nearly Hypersingular Integrals in the Boundary Element Method. Engineering Analysis with Boundary Elements, vol.25, no.3, pp. 165-184.
4. Tomioka, Satoshi; Nishiyama, Shusuke (2010):. Engineering Analysis with Boundary Elements, vol.34, no.4, pp. 393-404.
5. Lacerda, L.A. de; Wrobel, L.C. (2001): Hypersingular Boundary Integral Equation for Axisymmetric Elasticity. Int. J. Numer. Meth. Engng, vol.52, pp. 1337-1354.
6. Shiah, Y.C.; Shi, Yi-Xiao (2006): Heat conduction across thermal barrier coatings of anisotropic substrates. International Communications in Heat and Mass Transfer, vol.33, no.7, pp. 827-835.
7. Shiah, Y.C.; Hematiyan, M.R.; Chen, Y.H. (2013): Regularization of the boundary integrals in the BEM Analysis of 3D potential problems. Journal of Mechanics, vol.29, no.3, pp 385-401.
8. Shiah, Y.C. (2015): 3D Elastostatic boundary element analysis of thin Bodies by Integral Regularizations. (In press) Journal of Mechanics.
9. Cruse, T. A.; Richardson, J. D. (1996): Non-singular Somigliana stress identities in elasticity. International Journal for Numerical Methods in Engineering, vol. 39, no. 19, pp. 3273-3304.
10. Richardson, J. D.; Cruse, T. A. (1999): Weakly singular stress-BEM for 2-D elastostatics. International Journal for Numerical Methods in Engineering, vol.45, pp. 13-35.
11. Shiah, Y.C.; Tan, C.L.; Wang, C.Y. (2012): Efficient computation of the Green’s Function and its derivatives for three-dimensional anisotropic elasticity in BEM analysis. Engineering Analysis with Boundary Elements 36, pp. 1746-1755, 2012.
12. Tan, C. L., Shiah, Y. C., & Wang, C. Y. (2013). Boundary element elastic stress analysis of 3D generally anisotropic solids using fundamental solutions based on Fourier series. International Journal of Solids and Structures, 50(16), 2701-2711.ISO 690
13. Synge, J.L. (1957): The Hypercircle in Mathematical Physics, Cambridge University Press, Cambridge.
14. Barnett, D.M. (1972): The precise evaluation of derivatives of the anisotropic elastic Green’s functions. Phys. Stat. Sol. (b) 49, 741–748.
15. Ting, T.C.T.; Lee,V.G. (1997):The three-dimensional elastostic Green’s function for general anisotropic linear elastic solid. Q. J. Mech. Appl. Math., 50, 407-426.
16. Ting, T.C.T (1996): Anisotropic Elasticity, Oxford University Press, Oxford.
17. Shiah, Y.C.; Tan, C.L.; Lee, V.G.; Chen, Y.H. (2008a): Evaluation of Green’s functions for 3D anisotropic elastic solids. Advances in Boundary Element Techniques IX, Proc. BeTeq 2008 Conf., Seville, R. Abascal & M.H. Aliabadi (eds.),E.C. Ltd. (U.K.), pp. 119-124.
18. Lee,V.G. (2003): Explicit expression of derivatives of elastic Green’s functions for general anisotropic materials. Mech. Res. Comm., 30, 241–249.
19. Shiah, Y.C.; Tan, C.L.; Lee, V.G. (2008b): Evaluation of explicit-form fundamentalsolutions for displacements and stresses in 3D anisotropic elastic solids. CMES:Computer Modeling in Engineering & Sciences, 34, 205-226.
20. Ting T.C.T and Lee V.G., 1997. The Three-Dimensional Elastostatic Green’s Function for General Anisotropic Linear Elastic Solids, Q. JI Mech. Appl. Math., Vol. 50, Pt.3.
21. Shiah, Y.C., Tan, C.L., and Wang, C.Y., 2012. Efficient computation of the Green’s function and its derivatives for three-dimensional anisotropic elasticity in BEM analysis. Eng. Anal. Boundary Elem., 36, 1746-1755.
22. Tan, C. L., Shiah, Y. C., & Wang, C. Y. (2013). Boundary element elastic stress analysis of 3D generally anisotropic solids using fundamental solutions based on Fourier series. International Journal of
solids and Structures, 50(16), 2701-2711.
23. Ting T.C.T and Lee V.G., 1997. The Three-Dimensional Elastostatic’s
Green’s Function for General Anisotropic Linear Elastic Solids, Q. JI
Mech. Appl. Math., Vol. 50, Pt.3.
24. Lee,V.G., “Derivatives of the Three-dimensional Green’s Functions for ----anisotropic Materials’’,International Journal of Solid and Structures,2009.
25. Shiah, Y. C., Tan, C. L., & Lee, R. F. (2010). Internal point solutions for displacements and stresses in 3D anisotropic elastic solids using the boundary element method. Computer Modeling in Engineering and Sciences, 69(2), 167.
26. Heywood, R.B. Designing by photoelasticity. Chapman and Hall, 1952.
27. Peterson, R.E. Stress concentration factors. John Wiley & Sons, 1974.
28. Pilkey, W.D. Peterson’s stress concentration factors. New York: John ----Wiley & Sons Inc., 2nd Edition, 1997.
29. Howland, R.C.J. On the stresses in the neighborhood of circular hole in a strip under tension. Phil. Trans. Roj. Soc.,Voi. 229, 1929, p. 49-86.
30. Lekhnitskii, S.G. Anisotropic plates. Gordon and Breach, 1968
31. Tan, S.C. Finite-width correction factors for anisotropic plate containing a central opening. J. of Composite Materials, Voi. 22, 1988, p. 1080-18.
32. https://accuratus.com/alumox.html
33. https://www.azom.com/article.aspx?ArticleID=9558