Seismic Performance and Lateral Stability of RC Frames with Vertical Irregular Infill Arrangements

In this paper, the effects of vertical irregularity of masonry-infill wall arrangements on the seismic performance and lateral stability of reinforced concrete (RC) frames have been investigated using nonlinear response history analysis. Discrete finite element models, which are endowed with a damage-based cohesive crack modeling, were developed for six prototype structures with different arrangements of infill panels. The analysis of failure modes and lateral force transfer mechanisms of infilled frames shows that the arrangement of infill panels can critically affect the dynamic properties and structural stability under seismic excitations. Diagonal continuity, infill ratios, and eccentricity of infill walls play essential roles in the lateral-load and displacement capacities of the structures. The hysteresis behavior, failure modes, and force transfer mechanisms of RC frames with concentric and eccentric arrangements of infill panels are compared and their implications on the seismic resistant design are discussed.