Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2008.394.406MortezaeiAlirezaKheyroddinAli3200883In order to analysis of reinforced concrete structures subjected to general loading conditions, realistic constitutive models and analytical procedures are required to produce reasonably accurate simulations of behavior. In this study, an analytical model which can predict the nonlinear behavior of Reinforced Concrete (RC) structures such as flanged shear walls subjected to shear and normal stresses is introduced. The proposed model includes the description of biaxial failure criteria which show compressive strength enhancement and tensile resistance reduction effects for the stress states of biaxial compression and tension-compression, respectively. After tensile cracking, concrete compressive strength degradation was implemented and the tensile capacity of concrete maintained by the reinforcing steel (tension-stiffening effect) is considered. Using the concept of average stresses and strains, a criterion is proposed to simulate the tension-stiffening effect based on the force equilibriums and compatibility conditions. The finite element model predictions are validated by comparison with available experimental data. In addition, correlation studies between analytical results and experimental values from idealized shear walls tests were conducted. Load-displacement relations of shear walls under various stress conditions are then evaluated to verify the accuracy of the proposed model.]]>ASCE,1982Ashour, A.F. and C.T. Morley,1993Bazant, Z.P. and B.H. Oh,1983Belytschko, T., Z.P. Bazant, Y.W. Hyun and T.P. Chang,1986Campione, G. and L. La Mendola,2004Chen, W.F.,1982Choi, C.K. and S.H. Cheung,1996Chung, H., K. Yang, Y. Lee and H. Eun,2002Darwin, D. and D.A. Pecknold,1977Gupta, A.K. and S.R. Maestrini,1989Gupta, A.K. and S.R. Maestrini,1990Hegemier, G.A., H. Murakami and L.J. Hageman,1985Kheyroddin, A.,1996Shayanfar, M.A., A. Kheyroddin and M.S. Mirza,1997Kupfer, H.B., H.K. Hilsdorf and H. Rusch,1969Kwak, H. and D. Kim,2004Kwak, H. and D. Kim,2006Martin-Perez, B. and S.J. Pantazopoulou,2001Pastor, J.A.,1986Palermo, D. and F.J. Vecchio,2004Iyengar, K.S.R., S. Raviraj and T.N. Jayaram,2002Van der Put, T.A.C.M.,2007Vecchio, F.J.,1999Vecchio, F.J. and D. Palermo,2002Wallace, J.W. and J.H. Thomsen,1995