عنوان مقاله [English]
In the last decade, conventional materials such as steel and concrete are being replaced by fiber reinforced polymer (FRP) materials for the strengthening of concrete structures. Among the strengthening techniques based on Fiber Reinforced Polymer composites, the use of near-surface mounted (NSM) FRP rods is emerging as a promising technology for increasing flexural and shear strength of deficient concrete, masonry and timber members. An artificial neural network is an information processing tool that is inspired by the way biological nervous systems (such as the brain) process the information. The key element of this tool is the novel structure of the information processing system. In engineering applications, a neural network can be a vector mapper which maps an input vector to an output one. In the present study, a new approach is developed to predict the behavior of strengthened concrete beam using a large number of experimental data by applying artificial neural networks. Having parameters used as input nodes in ANN modeling such as elastic modulus of the FRP reinforcement, the ratio of the steel longitudinal reinforcement, dimensions of the beam section, the ratio of the NSM-FRP reinforcement and characteristics of concrete, the output node was the flexural strength of beams. The idealized neural network was employed to generate empirical charts and equations to be used in design. The aim of this study is to investigate the behavior of strengthened RC beam using artificial neural networks.
 ACI Committee 440. (2002). Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures. American Concrete Institute, ACI Committee 440, 118pp.
 Kheyroddin, A., Hoseini Vaez, S.R. and Naderpour, H. (2008). Numerical analysis of slab-column connections strengthened with carbon fiber reinforced polymers. Journal of Applied Sciences, 8(3), pp. 420-431.
 Kheyroddin, A., Naderpour, H., Ghdrati Amiri, Gh. and Hoseini Vaez, S.R. (2011). Influence of carbon fiber reinforced polymers on upgrading shear behavior of RC coupling beams. Iranian Journal of Science and Technology. Transactions of Civil Engineering, 35(C2), pp. 155-169.
 Naderpour, H., Kheyroddin, A., Ghdrati Amiri, Gh. and Hoseini Vaez, S.R. (2011). Estimating the Behavior of FRP-Strengthened RC Structural Members Using Artificial Neural Networks. Procedia Engineering, 14, pp. 3183-3190.
 De Lorenzis, L. and Nanni, A. (2001). Shear strengthening of reinforced concrete beams with near-surface mounted fiber-reinforced polymer rods. ACI Structural Journal, 98(1), pp.60-68.
 Barros, JA.O. and Fortes, A.S. (2005). Flexural strengthening of concrete beams with CFRP laminates bonded into slits. Cement and Concrete Composites, 27(2), pp. 471-80.
 De Lorenzis, L. and Teng, J.G. (2007). Near-surface mounted FRP reinforcement: an emerging technique for strengthening structures. J Compo Part B: Eng, 38(2), pp. 119–143.
 Yost, J.R., Gross, S.P., and Dinehart, D.W. (2004). Near surface mounted CFRP reinforcement for structural retrofit of concrete flexural members. In: 4th Int. Conf. on Advanced Composite Materials in Bridges and Structures, Calgary, Canada.
 Barros, J.A., and Fortes, A.S. (2005). Flexural strengthening of concrete beams with CFRP laminates bonded into slits. Cement and Concrete Composites,27(4), pp. 471-480.
 Badawi, M., and Soudki, K. (2009). Fatigue behavior of RC beams strengthened with NSM CFRP rods. Journal of Composites for Construction, 13(5), pp. 415-421.
 Tang, W.C., Balendran, R.V., Nadeem, A., and Leung, H.Y. (2006). Flexural strengthening of reinforced lightweight polystyrene aggregate concrete beams with near-surface mounted GFRP bars. Building and environment, 41(10), pp. 1381-1393.
 Perera, R., Tarazona, D., Ruiz, A., and Martín, A. (2014). Application of artificial intelligence techniques to predict the performance of RC beams shear strengthened with NSM FRP rods: Formulation of design equations. Composites Part B: Engineering, 66, pp. 162-173.
 Capozucca, R. (2013). Analysis of bond-slip effects in RC beams strengthened with NSM CFRP rods. Composite Structures, 102, pp. 110-123.
 Wahab, N., Soudki, K.A., and Topper, T. (2010). Mechanism of bond behavior of concrete beams strengthened with near-surface-mounted CFRP rods. Journal of Composites for Construction, 15(1), pp. 85-92.
 Al-Mahmoud, F., Castel, A., François, R., and Tourneur, C. (2009). Strengthening of RC members with near-surface mounted CFRP rods. Composite Structures, 91(2), pp. 138-147.
 Teng, J.G., De Lorenzis, L., Wang, B., Li, R., Wong, T.N., and Lam, L. (2006). Debonding failures of RC beams strengthened with near surface mounted CFRP strips. Journal of composites for construction, 10(2), pp. 92-105.
 Singh, S.B., Reddy, A.L., and Khatri, C.P. (2013). Experimental and Parametric Investigation of Response of NSM CFRP-Strengthened RC Beams. Journal of Composites for Construction, 18(1).
 Jung, W.T., Park, Y.H., Park, J.S., Kang, J.Y., and You, Y.J. (2005). Experimental investigation on flexural behavior of RC beams strengthened by NSM CFRP reinforcements. In: 7th International Symposium on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures, FRPRCS-7, pp. 7-10.
 Almusallam, T.H., Elsanadedy, H.M., Al-Salloum, Y.A., and Alsayed, S.H. (2013). Experimental and numerical investigation for the flexural strengthening of RC beams using near-surface mounted steel or GFRP bars. Construction and Building Materials, 40, pp. 145-161.
 De Lorenzis, L., and Nanni, A. (2002). Bond between near-surface mounted fiber-reinforced polymer rods and concrete in structural strengthening. ACI structural Journal, 99(2), pp. 123-132.
 Soliman, S.M., El-Salakawy, E., and Benmokrane, B. (2008). Flexural behaviour of concrete beams strengthened with near surface mounted FRP bars. In: 4th International Conference on FRP Composites in Civil Engineering, CICE2008, pp. 22-24.
 Ceroni, F. (2010). Experimental performances of RC beams strengthened with FRP materials. Construction and Building Materials, 24(2), pp. 1547-1559.
 Sharaky, I.A., Torres, L., Comas, J., and Barris, C. (2014). Flexural response of reinforced concrete (RC) beams strengthened with near surface mounted (NSM) fibre reinforced polymer (FRP) bars. Composite Structures, 109, pp. 8-22.
 Täljsten, B., Carolin, A., and Nordin, H. (2003). Concrete structures strengthened with near surface mounted reinforcement of CFRP. Advances in structural engineering, 6(3). pp. 201-213.
 Al-Mahmoud, F., Castel A. and Françoi, R. (2012). Failure modes and failure mechanisms of RC members strengthened by NSM CFRP composites – Analysis of pull-out failure mode. Composites: Part B, 43(4), pp. 1893–1901.
 Hassan T and Rizkalla S. (2004). Bond mechanism of NSM FRP for flexural strengthening of concrete structures. ACI Struct J, 101(6), pp. 830–839.