This paper presents a nonlinear finite element analysis of non-seismically detailed RC beam column connections under reversed cyclic load. The test of half-scale nonductile reinforced concrete beam-column joints was conducted. The tested specimens represented those of the actual mid-rise reinforced concrete frame buildings designed according to the non-seismic provisions of the ACI building code. The test results show that specimens representing small and medium column tributary area failed in brittle joint shear while specimen representing large column tributary area failed by ductile flexure though no ductile reinforcement details were provided. The nonlinear finite element analysis was applied to simulate the behavior of the specimens. The finite element analysis employs the smeared crack approach for modeling beam, column and joint, and employs the discrete crack approach for modeling the interface between beam and joint face. The nonlinear constitutive models of reinforced concrete elements consist of coupled tension-compression model to model normal force orthogonal and parallel to the crack and shear transfer model to capture the shear sliding mechanism. The FEM shows good comparison with test results in terms of load-displacement relations, hysteretic loops, cracking process and the failure mode of the tested specimens. The finite element analysis clarifies that the joint shear failure was caused by the collapse of principal diagonal concrete strut.
Warnitchai, P. (2004), Development of seismic design requirements for buildings in Bangkok against the effects of distant large earthquakes. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver.
Aoyama, H. (1981), Amethod for the evaluation of the seismic capacity of existing RC buildings in Japan. Bulletin of the NZ National Society for Earthquake Engineering, pp. 105-130.
Fintel, M. (1991), Shear walls-an answer for seismic resistance?. Construction International, pp. 48-53.
Bing, L. and Tso-Chien, P. (2004), Seismic performance of reinforced concrete frames under low intensity earthquake effects. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver.
Warnitchai, P., Pimanmas, A., and Thinth, D.T. (2004), Seismic performance of RC subassemblages with non-seismic reinforcement details. Proceedings of the First Asian Conference for Earthquake Engineering, Phillipines.
Maekawa, K., Pimanmas, A., and Okamura, H. (2003), Nonlinear mechanics of reinforced concrete. Son Press.
Vecchio, F.J. and Collins, M.P. (1986), The modified compression field theory for reinforced concrete elements subjected to shear. ACI Structural Journal, vol. 83(2), pp. 219231.
Vecchio, F.J. and Collins, M.P. (1988), Predicting the response of reinforced concrete beams subjected to shear using the modified compression field theory. ACI Structural Journal, vol. 85(4), pp. 258-268.
Salem, H. and Maekawa, K. (2002), Spatially averaged tensile mechanics for cracked concrete and reinforcement under highly inelastic range, J Materials Conc Struct Pavements, JSCE, vol. 613(42), pp. 227-293.