Numerical investigation of masonry infilled RC frames

Nonlinear numerical simulations have been widely used to study the inelastic response of reinforced concrete structures as well as load bearing masonry walls subjected to earthquake loading. While experimental investigations in this field are usually associated with large investments, numerical simulations, once validated, offer an efficient approach for parametric studies. Due to the more complex inelastic behaviour of reinforced concrete frames with masonry infills, efficient and validated simulation models are needed to mirror the nonlinear behaviour. Although a lot of research in this field has been performed most of the approaches are valid only for special case applications and models for general applications are lacking. This work describes a micro modelling approach which applies finite element method that takes into account the complexities arising from the nature of the different materials as well as the interfaces between them. The complex behaviour is captured by a detailed modelling of the bricks and their interaction among each other and to the surrounding reinforced concrete frame. The frame is represented by a nonlinear reinforced concrete model which considers the arrangement of the reinforcement. Experimental results of a bare reinforced concrete frame and a frame with masonry infill walls are employed to validate the numerical calculations, so as to be used for further parametric studies. The adopted numerical models are capable to describe the inelastic behaviour of the system, as indicated by the obtained results of the overall structural response as well as the damage propagation within the infill wall. Comparison between the experimental and numerical results highlights the valuable contribution of validated numerical simulations to derive rational recommendations for the design of masonry infilled frames.