Energy-based cyclic force-displacement relationship for reinforced concrete short coupling beams

For use in the inelastic analysis of coupled walls, the cyclic force-displacement relationship and energy dissipation of short coupling beams with various reinforcement layouts were studied. First, a nonlinear truss model analysis was performed to investigate the cyclic behavior of short coupling beams. The results of this numerical analysis showed that the hysteretic energy of the short coupling beams was dissipated mainly by the diagonal reinforcing bars rather than by the concrete and conventional longitudinal and transverse reinforcing bars. Based on this result, simplified methods for predicting the energy dissipation and force-displacement relationship of short coupling beams with various reinforcement layouts were developed. The hysteretic energy dissipation was calculated as the sum of the plastic energies dissipated by the diagonal reinforcing bars. The cyclic force-displacement relationship was defined in a manner such that the area enclosed by the cyclic curve was the same as the predicted hysteretic energy dissipation. For verification, the proposed method was applied to existing test specimens. (C) 2009 Elsevier Ltd. All rights reserved.