Numerical Simulation of Masonry-Infilled RC Frames Using XFEM

Evaluation of the seismic performance of masonry-infilled reinforced concrete (RC) frames is challenging because a number of damage patterns can be induced by the interaction between the infill and the frame. In this paper, the extended finite-element method (XFEM) is adopted to model the cracking behavior and the compressive failure of concrete in frame members as well as masonry units in infill panels, and the discrete interface element is employed to simulate the behavior of the masonry mortar joints and the joints at the frame-to-infill interface. With the XFEM, the crack can propagate in an arbitrary manner during the analysis. In addition, multiple continuous cracks are allowed in this model. The nonlinear finite-element model is validated by the available experimental data. It can be concluded that the proposed model is capable of predicting the load-displacement response of a masonry-infilled RC frame structure. The damage patterns regarding cracking and crushing of frame members and masonry panels, tensile fracture and compressive compaction in mortar joints, and shear sliding of masonry units along mortar joints are also reproduced very well.