ANALYTICAL MODELLING OF MASONRY-INFILLED STEEL FRAMES

Masonry itself is a composite heterogeneous material whose structural behaviour is strongly affected by many influencing parameters with a wide range of possible values, construction procedures as well as care methods taken afterwards. When the masonry panel is added into the surrounding frame the complex interactive frame-infill system is established exhibiting highly nonlinear inelastic structural behaviour. Therefore, the analytical modelling of masonry-infilled frame structures is a very complex task that demands various data matching given in-situ conditions, otherwise applied methods and analytical models used have only a theoretical value. In this paper analytical modelling of infilled steel frame structures is based on previously experimentally calibrated data. The base for calibration of analytical models was experimental testing of one-bay, one-storey infilled steel frames conducted at the Faculty of Civil Engineering, Josip Juraj Strossmayer University of Osijek. Two series by three steel frames were infilled with perforated clay blocks ('strong infill') and autoclaved aerated concrete blocks ('weak infill') respectively. The significant difference in structural behaviour of these two kinds of masonry infill is observed and modelled. The macro-models (single-strut and three-strut model and infill-panel macro-model) and detailed 2D micro-models were applied. A total of eight analytical models were analysed with their relevant characteristics along with the quality of representation of the measured global and local results as well as their applicability.