Analytical Modeling of Diagonally Reinforced Concrete Coupling Beams under Lateral Loads

This thesis describes an analytical model to investigate the nonlinear behavior of diagonally reinforced concrete coupling beams under reversed-cyclic lateral loading. The analytical model decomposes a coupling beam into two main components: (1) the concrete beam and any horizontal reinforcement that it contains; and (2) the diagonal reinforcement. The diagonal reinforcement is modeled using nonlinear truss elements in the diagonal direction whereas the concrete beam is modeled using nonlinear fiber beam-column elements in the horizontal direction. The diagonal elements are slaved to the horizontal elements at intermediate and end nodes along the span of the beam. The analytical model is verified by comparing the measured behavior of coupling beam test specimens from previous research with analytical estimations. It is shown that as compared to prior analytical models, the proposed model introduces a significant improvement on the modeling of diagonally reinforced coupling beams.