Three‐Dimensional Effects in Lateral Behavior of Frame‐Wall Systems

Within the U.S.‐Japan Cooperative Research Program, a full‐scale model of an RC seven‐story building was built and subjected to pseudodynamic testing, with a large number of interesting results. In the present research, attention is devoted to a specific experimental result, showing an interaction between parallel frames. This phenomenon is related to the coupling action of transversal beams and has been designated the three‐dimensional effect. An interpretation of the experimental results is attempted through a finite element nonlinear static model, representing the first floor of the test structure. A concrete model including a smeared cracking capability was used, which allowed the sequence of crack opening and propagation through the shear wall to be followed. The large strains occurring in the tension side of this wall were highlighted as the mechanism generating the three‐dimensional effect. An estimation of the contribution of this effect toward resisting the global overturning moment is made. The computed response of the system is shown to have a dependence on the level of tension stiffening present in the concrete.