Research in Engineering and Aviation

Simplified Trilinear Behavior of Diagonally Reinforced Coupling Beams

March 2007

Author(s): Hindi, R., Hassan, M.

Journal: ACI Structural Journal, 104(2), March 2007, pp. 199-206.


This paper presents a simplified procedure to predict the monotonic behavior of diagonally reinforced coupling beams of shearwalls. The procedure yields a trilinear monotonic force-displacement response up to failure. The proposed simplified procedure can be easily used by design engineers. The procedure assumes all load is resisted by diagonal tension and compression. The diagonal compression is carried by the diagonal reinforcement and the concrete core, while the diagonal tension is carried only by the diagonal reinforcement. Either rupture of the diagonal reinforcement or crushing of the concrete core defines failure point of the coupling beam. The proposed trilinear approximation is applied and compared with 13 specimens that were experimentally tested by other investigators. The specimens vary in terms of dimensions, reinforcement, and material properties.