Nonlinear analysis of RC beam subject to cyclic loading

A hysteretic moment-curvature relationship to simulate the behavior of a re inforced concrete (RC) beam under cyclic loading is introduced in this pape r, and the nonlinear behavior of RC beams subjected to flexural cyclic load ing is analyzed by means of the proposed model. Unlike previous moment-curv ature models and the layered-section approach, the proposed model takes bon d-slip effects into account by using the monotonic moment-curvature relatio nship constructed on the basis of the bond-slip relation and the correspond ing equilibrium equation at each nodal point. In addition, in contrast to l inearized hysteretic curves, the use of curved unloading and reloading bran ches inferred from the stress-strain relation of steel considering the Baus chinger effect gives more accurate structural responses. This follows a cor rect assessment of the energy-absorbing capacity of the structure at large deformations. The advantages of the proposed model, compared with the layer ed-section approach, may be in the reduction in calculation time and memory space in applications to large-frame structures with many degrees of freed om. Modifications of the moment-curvature relationship to reflect the fixed -end rotation and pinching effect are also introduced. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.