FRAME - INFILL INTERACTION UNDER HORIZONTAL LOAD

The behavior of building frames under lateral loads such as those created by earthquakes is significantly influenced by the presence of infill walls. In the present investigation a nonlinear stress analysis is carried out of a portal frame with a partial infill wall under increasing horizontal load using a general purpose program. The concrete frame is modeled as an assemblage of one-dimensional elastic finite elements, whereas the infill is represented by two-dimensional "stretching" rectangular finite elements. The structural behavior of the frame is studied in detail for increasing heights of infill, and the force - horizontal deflection relationship is examined for two different thicknesses of infill. The enhanced shear forces in the columns at the top level of the infill are also evaluated