The role of masonry infills on the interstory drift demand of reinforced concrete frames

Abstract

Most frame buildings, especially those with shear-type moment resistance frames, are affected by masonry infill panels, which change the mechanical properties of whole systems in a big way. In turn, seismic performance varies depending on the infill panel and frame interactions. In conventional structural design practice, such interaction has been overlooked. This study looks at the range of local displacement demands in shear-type frames with and without infill panels. Generic frames are developed by tuning the story stiffness and mass to produce a reasonable period range between 0.2 and 2.0 s. The masonry infill panels are simulated through equivalent diagonal struts. A Bouc–Wen-based hysteretic model is applied to incorporate the post-yielding hysteresis degradations of both columns and masonry panels. The hysteresis loop control parameter values are also given for incorporating masonry infill properties. The correlation analysis between the strength and stiffness of RC frames and masonry infills is supplied as an instrument for calibrating the hysteretic model. In the collection of records, there are a lot of near-fault ground motions, which puts a lot of seismic demands on the buildings. The modification factors via regression analysis are proposed using over 1254 nonlinear response history analyses. This modification factor is figured out by looking at the difference between the mean drift spectrum for a set of generic frames that are both bare and filled. The nonlinear analysis shows that residual drift demands can be reduced in the case of panel effects that exist for masonry-infilled mid-rise RC shear-type frames.