Project presents an analytical method for the prediction of inelastic response of RC beam columns under both monotonic and cyclic loading up to large deformation stage. Several computer programs were developed for the prediction of moment-curvature and lateral load-lateral displacement curves from which ductility factors were derived.

Beam-columns are structural members subjected to combined flexure and axial compression. Response of reinforced concrete (RC) beam-columns to loading is significantly nonlinear due to the effect of axial load on bending moment and the nonlinearity in material response. Formation of cracks, bond deterioration between reinforcing steel and surrounding concrete, post-peak softening and localised failure mechanism are factors that induce more complexities in the prediction of the inelastic response of RC beam-columns. Design of RC beam-columns in seismic regions is governed by the ductility consideration. Experimental results indicate that ductility is significantly enhanced by the confinement provided by the transverse reinforcements. This thesis presents an analytical method for the prediction of the inelastic response of RC beam- columns under cyclic (including monotonic) loading up to large deformation stage. The response is represented the form of moment-curvature and lateral load-lateral displacement curves from which ductility factors are derived. The response of RC beam-column was observed to be a function of the response of its constituent materials. Well-established stress-strain relations for steel and concretes were used in this research. The effect of transverse reinforcement was included in the material model. An analytical tool the form of computer programs was developed. The accuracy of the results predicted by the computer programs was verified using experimental results of twelve RC beam-column specimens published the literature. Comparison between the results of the computer programs and the experimental results showed very good agreement, thus validating the programs. Sensitivity of the design parameters on the response ofRC beam-columns to monotonic and cyclic loadings was studied using the computer programs. The design parameters that were considered this study include (1) volumetric ratio of transverse steel, ( 2) yield strength of transverse steel, (3) level of compressive axial load, (4) compressive strength of concrete, (5) yield strength of longitudinal steel and (6) longtudinal steel ratio. The results of these sensitivity analyses have the potential to be used by the design engineers for the selection of the most appropriate design variables for specific performance requirements.