Title:
Finite Element Modeling of the Bond-Slip Behavior of CFRP Anchors
Author(s):
Jose Luis Jimenez and Hernan Santa Maria
Publication:
Symposium Paper
Volume:
356
Issue:
Appears on pages(s):
238-257
Keywords:
bond-slip law, CFRP anchors, push-pull tests, single-lap, 2D FEM
DOI:
10.14359/51737274
Date:
10/1/2022
Abstract:
CFRP reinforcement has become a consolidated technology in the retrofit of existing structures. Extensive experiments have shown that delamination of externally bonded CFRP plies governs their failure mode. To delay delamination, CFRP anchors are particularly attractive due to their wide range of applicability and large increases in strength and deformability. This paper presents a 2D finite element model for single-lap push-pull tests of concrete blocks reinforced with CFRP subject to monotonic loading. A numerical model is implemented to simulate the bond between CFRP anchors and concrete. CFRP anchors present a complex geometry and a combined tensional state of tangential and normal stresses. For these reasons it is difficult to determine a bond-slip law for CFRP anchors; however, with the proposed procedure the necessary parameters are obtained numerically, at a low computational cost. Experiments taken from literature with a single CFRP anchor are replicated and used to capture the parameters of the bond-slip curve for a particular anchor. The procedure is then validated with experiments with two and three anchors. The proposed procedure achieves reasonable results when comparing the obtained maximum strength achieved, the strains along with the CFRP reinforcement, and the anchor stress behavior with the experiments.
Related References:
1. ACI Committee 440.2R, Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures (ACI 440.2R-17). Farmington Hills, MI: American Concrete Institute, 2017.
2. fib Bulletin 14, Externally bonded FRP reinforcement in RC structures. Lausanne, Switzerland, 2001.
3. CNR-DT200, Guide for the design and construction of externally bonded FRP systems for strengthening existing structures. Rome, 2004.
4. H. W. Zhang and S. T. Smith, “Influence of FRP anchor fan configuration and dowel angle on anchoring FRP plates,” Compos. Part B Eng., vol. 43, no. 8, pp. 3516–3527, 2012.
5. H. Zhang, Influence of FRP anchors in FRP-to-concrete bonder interfaces. Hong Kong: PhD Thesis. The University of Hong Kong, 2013.
6. H. Zhang and S. T. Smith, “Fibre-reinforced polymer (FRP)-to-concrete joints anchored with FRP anchors: Tests and experimental trends,” Can. J. Civ. Eng., vol. 40, no. 11, pp. 1103–1116, 2013.
7. C. W. Niemitz, R. James, and S. F. Breña, “Experimental Behavior of Carbon Fiber-Reinforced Polymer (CFRP) Sheets Attached to Concrete Surfaces Using CFRP Anchors,” J. Compos. Constr., vol. 14, no. 2, pp. 185–194, 2010.
8. S. F. Breña and G. N. McGuirk, “Advances on the Behavior Characterization of FRP-Anchored Carbon Fiber-Reinforced Polymer (CFRP) Sheets Used to Strengthen Concrete Elements,” Int. J. Concr. Struct. Mater., vol. 7, no. 1, pp. 3–16, 2013.
9. I. A. Cortez Flores, J. Fernández Gómez, and P. Villanueva Llauradó, “Influence of multiple anchor arrangement in the behaviour of FRP-to-concrete anchored joints,” Compos. Struct., vol. 230, p. 111528, 2019.
10. A. T. Al-Sammari and S. F. Breña, “Finite element simulation and parametric study of anchored fiberreinforced polymer sheets,” ACI Struct. J., vol. 115, no. 2, pp. 365–377, 2018.
11. M. Smith, ABAQUS/Standard User’s Manual, Version 6.9. Providence, RI: Dassault Systemes Simulia Corp, 2009.
12. Z. Hashin, “Failure Criteria for Unidirectional Fiber Composites,” J. Appl. Mech., vol. 47, no. June, pp. 329–334, 1980.
13. R. Kalfat, “Anchorage Systems in Concrete Structures Strengthened with Carbon Fiber Reinforced Polymer,” no. February 2014.
14. A. N. Al-saoudi, “INVESTIGATION OF THE PERFORMANCE OF FIBRE REINFORCED POLYMERS ANCHORAGE DEVICES IN STRENGTHENING CONCRETE BRIDGE BEAMS SUBJECTED TO,” no. April 2018.
15. J. C. Vladimir Cervenka, Libor Jedele, “ATENA Program - Part 1 Theory,” Program, 2018.
16. J. Q. Yang, S. T. Smith, Z. Wang, and Y. Y. Lim, “Numerical simulation of FRP-strengthened RC slabs anchored with FRP anchors,” Constr. Build. Mater., vol. 172, pp. 735–750, 2018.
17. A. Jawdhari and I. Harik, “Finite element analysis of RC beams strengthened in flexure with CFRP rod panels,” Constr. Build. Mater., vol. 163, pp. 751–766, 2018.
18. M. M. A. Kadhim, A. Jawdhari, and A. Peiris, “Evaluation of lap-splices in NSM FRP rods for retrofitting RC members,” Structures, vol. 30, no. August 2020, pp. 877–894, 2021.
19. M. M. A. Kadhim, A. Jawdhari, and A. Peiris, “Development of hybrid UHPC-NC beams: A numerical study,” Eng. Struct., vol. 233, no. January, p. 111893, 2021.
20. H. Zhang, S. T. Smith, R. J. Gravina, and Z. Wang, “Modeling of FRP-concrete bonded interfaces containing FRP anchors,” Constr. Build. Mater., vol. 139, pp. 394–402, May 2017.
21. A. B. Sturm, P. Visintin, J. Vaculik, D. J. Oehlers, R. Seracino, and S. T. Smith, “Analytical approach for global load-slip behaviour of FRP plates externally bonded to brittle substrates with anchors,” Compos. Part B Eng., vol. 160, no. March 2018, pp. 177–194, 2019.
22. A. Melendo, A.; Coll, A.; Pasenau, M.; Escolano, E.; Monros, “GiD v.14 User Manual pdf.,” accessed 2020 May 25., 2018.
23. B. Al-Atta, R. Kalfat, R. Al-Mahaidi, and A. Al-Mosawe, “Finite element analysis of anchorage systems for flexural strengthening of concrete slabs using FRP materials,” APFIS 2019 Proc. - 7th Asia-Pacific Conf. FRP Struct., no. December, pp. 10–13, 2019.
24. ACI 447, Report on the Modeling Techniques Used in Finite Element Simulations of Concrete Structures Strengthened Using Fiber-Reinforced Polymer (FRP) Material (ACI-447.1R-18). Farmington Hills, MI, 2018.
25. D. Pryl and J. Červenka, “ATENA Program Documentation Part 11 Troubleshooting Manual,” Cerv. Consult., 2015.
26. H. Yuan, J. G. Teng, R. Seracino, Z. S. Wu, and J. Yao, “Full-range behavior of FRP-to-concrete bonded joints,” Eng. Struct., vol. 26, no. 5, pp. 553–565, 2004.
27. Y. J. Wang, Z. M. Wu, J. J. Zheng, R. C. Yu, and X. M. Zhou, “Three-dimensional axisymmetric analytical method for pull-out behaviour of adhesive anchors in concrete,” Eng. Fract. Mech., vol. 226, no. September 2019, p. 106876, 2020.
28. B. Zhang and B. Benmokrane, “Pullout bond properties of fiber-reinforced polymer tendons to grout,” J. Mater. Civ. Eng., vol. 14, no. 5, pp. 399–408, 2002.
29. L. Jendele and J. Cervenka, “Finite element modeling of reinforcement with bond,” Comput. Struct., vol. 84, no. 28, pp. 1780–1791, 2006.