Hysteretic behavior of the hybrid coupled partially encased composite wall system

In order to investigate the seismic behavior of the hybrid coupled partially encased composite (PEC) wall system, two 2/3-scale three-story specimens with different elastic coupling ratios (CRelastic) were tested under cyclic loading. The results showed that the hysteretic curves of the two specimens were full and stable, indicating their robust cyclic performance and excellent energy dissipation capacity. Under reversed cyclic lateral loading, the specimens exhibited a two-stage yielding energy dissipation mechanism, in accordance with theoretical expectations. Both specimens dissipated a large amount of energy during loading, with the equivalent viscous damping xi(eq) reaching 0.32 and 0.35 at the maximum displacement level, respectively. Based on the experimental results, the refined finite element model for the hybrid coupled PEC wall was established in ABAQUS and validated. A parametric analysis demonstrated that the CRelastic, and the design axial compression ratio (n) had significant influences on the seismic behavior of the hybrid coupled PEC wall. With increasing CRelastic, the lateral stiffness, strength, and yield displacement of the hybrid coupled PEC wall gradually increased, while its ductility deteriorated. Moreover, the ductility of the hybrid coupled PEC wall decreased with increasing n owing to the strong coupling action of the steel coupling beams. In order to ensure the good seismic performance and form a reasonable failure mode, the CRelastic, and n in the hybrid coupled PEC wall should not exceed 65% and 0.5, respectively.