Appraisal of masonry infill walls dynamic characteristics: An analytical study

Due to the infill masonry high vulnerability observed in recent earthquakes, the knowledge concerning the infills' out-of-plane seismic behaviour has been the focus of several research works in the last years. The inplane/out-of-plane interaction, boundary conditions, openings, slenderness, and aspect ratio have been reported as the main parameters that affect the out-of-plane infill wall capacity. However, the study of the impact of those parameters on the wall modal properties still needs further investigation. This research aims to perform a numerical study where a detailed numerical strategy is assumed to simulate the infilled reinforced concrete frames. The numerical model is calibrated using results from modal identification tests (wall with and without openings). A parametric study is carried out to assess the effect of wall geometry, slenderness, openings ratio, openings position and boundary conditions on the walls' out-of-plane frequencies. Eventually, analytical formulations were proposed to quantify the dynamic characteristics of the infill wall based on their geometric and mechanical characteristics.