Near free-edge stresses in FRP-to-concrete bonded joint due to mechanical and thermal loads

Document Type : Article

Authors

Faculty of Civil Engineering, Babol Noshirvani University of Technology, Babol, P.O. Box 484, Iran

Abstract

Over the last few decades, a considerable amount of theoretical and experimental investigations have been conducted on the mechanical strength of composite bonded joints. Nevertheless, many issues regarding the debonding behavior of such joints still remain uncertain. The high near free-edge stress fields in most of these joints are the cause of their debonding failure. In this study, the performance of an externally bonded fiber-reinforced polymer (FRP) fibrous composite to a concrete substrate prism joint subjected to mechanical and thermomechanical loadings is evaluated through employing the principles of lamination theory. An inclusive Matlab code is generated to perform the computations. The bond strength is estimated to take place in a region- also termed the boundary layer- where the peak interfacial shearing and transverse peeling stresses occur; whereas the preceding stress field is observed to be the main failure mode of the joint. The proposed features are validated through the existing experimental data points as well as the commercial finite element (FE) modeling software Abaqus. Comparison between the calculated and experimental results demonstrates favorable accord, producing quite a high average ratio. The current approach is advantageous to failure modeling analysis, optimal design of bonded joints, and scaling analyses among others.

Keywords

Main Subjects


Refrences:
1. Goncalves, J.P.M., de Moura, M.F.S.F., and de Castro, P.M.S.T. A three-dimensional finite element model for stress analysis of adhesive joints", Int. J. Adhesion and Adhesives, 22, pp. 357{365 (2002). 
2. Zhang, Y., Vassilopoulos, A., and Keller, T. Stiffness degradation and fatigue life prediction of adhesivelybonded joints for fiber-reinforced polymer composites", Int. J. Fatigue, 30, pp. 1813{1820 (2008). 
3. Hu, P., Shi, Z.W., Wang, X., et al. Strength degradation of adhesively bonded single-lap joints in a cyclic-temperature environment using a cohesive zone model", J. Adhesion, 91(8), pp. 587{603 (2015). 
4. Herakovich, C.T., Mechanics of Fibrous Composites, University of Virginia, John Wiley and Sons, Inc. (1998). 
5. Timoshenko, S. Analysis of bi-metal thermostats", J. Optical Society of America, 11(3), pp. 233{255 (1925). 
6. Volkersen, O. Die nietkraftverteilung in zugbeanspruchten nietverbindungen mit konstanten laschenquerschnitten", Luftfahrtforschung, 15, pp. 41{47 (1938). 
7. Delale, F., Erdogan, F., and Aydinoglu, M.N. Stresses in adhesively bonded joints: a closed-form solution", J. Composite Materials, 15, pp. 249{271 (1981). 
8. Chen, D. and Cheng, S. An analysis of adhesivebonded single-lap joints", J. Applied Mechanics- Transactions of ASME, 50, pp. 109{115 (1983). 
9. Keller, T. and Valle'e, T. Adhesively bonded lap joints from Pultruded GFRP profiles. Part I: Stress strain analysis and failure modes", J. Composites Part B: Eng., 36, pp. 331{340 (2004). 
10. Wu, Z. and Liu, Y. Singular stress _eld near interface edge in orthotropic/isotropic bi-materials", Int. J. Solids and Structures, 47, pp. 2328{2335 (2010). 
11. Sayman, O. Elastoplastic stress analysis in an adhesively bonded single-lap joint", J. Composites Part B, 43, pp. 204{209 (2012). H. Samadvand and M. Dehestani/Scientia Iranica, Transactions A: Civil Engineering 27 (2020) 2727{2739 2739 
12. Yousefsani, S.A. and Tahani, M. Analytic solution for adhesively bonded composite single-lap joints under mechanical loadings using full layerwise theory", Int. J. Adhesion and Adhesives, 43, pp. 32{41 (2013). 
13. Sundarraja, M.C. and Ganesh Prabhu, G. Flexural behavior of CFST members strengthened using CFRP composites", Int. J. Steel and Composite Structures, 15(6), pp. 623{643 (2013). 
14. Sharbatdar, M.K. and Jaberi, M. Flexural and shear strengthening of RC beams with NSM technique and manually made CFRP bars", Scientia Iranica A, 25(4), pp. 2012{2025 (2018). 
15. Saeidi Moein, R., Tasnimi, A.A., and Soltani Mohammadi, M. Flexural performance of RC beams strengthened by bonded CFRP laminates under monotonic and cyclic loads", Scientia Iranica A, 23(1), pp. 66{78 (2016). 
16. Mostofinejad, D. and Hosseini, S.J. Simulating FRP debonding from concrete surface in FRP strengthened RC beams: A case study", Scientia Iranica A, 24(2), pp. 452{466 (2017). 
17. Hejabi, H. and Kabir, M.Z. Analytical model for predicting the shear strength of FRP-retrofitted exterior reinforced concrete beam-column joints", Scientia Iranica A, 22(4), pp. 1363{1372 (2015). 
18. Talaeitaba, S.B. and Mostofinejad, D. Shear-torsion interaction of RC beams strengthened with FRP sheets", Scientia Iranica A, 22(3), pp. 699{708 (2015). 
19. Bazli, M., Ashraff, H., Jafari, A., et al. Effect of thickness and reinforcement con_guration on exural and impact behavior of GFRP laminates after exposure to elevated temperatures", J. Composites Part B, 157, pp. 76{99 (2019). 
20. Ghiassi, B., Soltani, M., and Rahnamaye Sepehr, S. Micromechanical modeling of tension stiffening in FRP-strengthened concrete elements", J. Composite Materials, 52(19), pp. 2577{2596 (2018). 
21. Zhao, Q., Qian, C.C., and Harper, L.T. Finite element study of the microdroplet test for interfacial shear strength: E_ects of geometric parameters for a carbon _bre/epoxy system", J. Composite Materials, 52(16), pp. 2163{2177 (2017). 
22. Kara, M.E. and Yacsa, M. An Investigation of fan type anchorages applied to end of CFRP strips", Int. J. Steel and Composite Structures, 15(6), pp. 605{621 (2013). 
23. El Mahi, B., Benrahou, K.H., Amziane, S., et al. Effect of tapered-end shape of FRP sheets on stress concentration in strengthened beams under thermal load", Int. J. Steel and Composite Structures, 17(5), pp. 601{621 (2014). 
24. Xin, H., Liu, Y., and Du, A. Thermal analysis on composite girder with hybrid GFRP-concrete deck", Int. J. Steel and Composite Structures, 19(5), pp. 1221{1236 (2015). 
25. Hadji, L., Hassaine, D.T., Ait Amar Meziane, M., et al. Analyze of the interfacial stress in reinforced concrete beams strengthened with externally bonded CFRP plate", Int. J. Steel and Composite Structures, 20(2), pp. 413{429 (2016). 
26. Yazdani, S.H. and Hojjati, M. A high-order analytical method for thick composite tubes", Int. J. Steel and Composite Structures, 21(4), pp. 755{773 (2016). 
27. Singh, S.K. and Chakrabarti, A. Hygrothermal analysis of laminated composites using C0 FE model based on higher order zigzag theory", Int. J. Steel and Composite Structures, 23(1), pp. 41{51 (2017). 
28. Beer, F., Johnston, E.R., Dewolf, J.T., and Mazurek, D.F., Mechanics of Materials, 5th Ed., McGraw Hill Press, New York (2009). 
29. Suhir, E. Thermally induced interfacial stresses in elongated bimaterial plates", J. Applied Mechanics Review, 42, pp. 253{262 (1989). 
30. Eischen, J.W., Chuang, C., and Kim, J.H. Realistic modeling of edge effect stresses in bimetallic elements", J. Electronic Packaging, 112, pp. 16{23 (1990). 
31. Ru, C.Q. Interfacial thermal stresses in bimaterial elastic beams: modified beam models revisited", J. Electronic Packaging-Transactions of ASME, 124, pp. 141{146 (2002). 
32. Wu, X.F. and Jenson, R.A. Stress-function variational method for stress analysis of bonded joints under mechanical and thermal loads", Int. J. Engineering Science, 49, pp. 279{294 (2011).
Volume 27, Issue 6 - Serial Number 6
Transactions on Civil Engineering (A)
November and December 2020
Pages 2727-2739
  • Receive Date: 14 March 2018
  • Revise Date: 24 September 2018
  • Accept Date: 24 December 2018