Stiffness Contributed by Infill to RC Frames using Finite Element Method Approach

Abstract

Natural Calamities such as Earthquakes and cyclones cause lateral forces in buildings. Tall Buildings are highly vulnerable to these lateral forces. Designing such
buildings to withstand the lateral forces which occur occasionally is considered very expensive. The lateral strength contributed by the infill wall elements is considered to be substantial. Many researchers have adopted different methods to evaluate the lateral strength contributed by wall panels, as on today no complete method has been evolved successfully.  In the present work, the lateral strength contributed by the infill panels is explored making use of Finite Element concept. The general purpose of Finite Element package by name MSC NASTRAN is used for the needful calculations. Essentially the Strain Energy contributed by the infill panel in the composite frame structure is equated to the strain energy contributed by an equivalent diagonal strut replacing the infill panel together with bounding frame. Width of such strut is evaluated analytically using MSC NASTRAN. The calculations for strain energy with equivalent diagonal struts is taken-up using STAAD Pro for comparison.