Effect of Infill Walls at Framed Structures: State of the Art

Abstract

In a current design, the masonry infill walls are neglected, being considered nonstructural elements. Numerous experimental and numerical studies have shown that the infill walls at framed buildings significantly affect the strength and rigidity of the structure. The modeling of the infill walls represents a complex issue and involves some difficulties. Micro-modeling is a more accurate approach, but it requires a great computational effort and long time for analysis. Macro-modeling is a more simplified analytical method, which consists in replacing the infill panel with an equivalent diagonal compressive strut. As the single strut model cannot consider the effects resulting from the frame-infill interaction (bending moments, shear forces and position of the plastic hinges in the frame elements are unrealistic) the researchers proposed multiple struts models. The most used such models in the analysis of framed structures to seismic action (lateral loading) are detailed in this paper. The main objective of the research in progress is to develop a macro-model that can be successfully used in the analysis of structures to progressive collapse (vertical loading). For this aim, a through overview, mainly of the recent studies that investigate the progressive collapse resistance of infilled frame structures was performed.