Investigation on the influence of previous in-plane loading on the out-of-plane behavior of the innovative damped masonry infill wall

Abstract

The damped masonry infill wall (DMIW) is an innovative masonry infill wall (MIW), wherein multiple horizontal subpanels, also called masonry units, are subdivided by inserting the horizontal damping layer joints (DLJs). While existing research on DMIW primarily focuses on its pure in-plane (IP) and pure out-of-plane (OOP) behavior, it is crucial to account for the interaction effect between IP and OOP behaviors to accurately assess OOP performance, Failure to consider this interaction may lead to an overestimation of OOP capacity, a concern previously highlighted in traditional MIW studies. Addressing this gap, this study conducts a sequential experiment involving IP cyclic quasi-static loading followed by OOP monotonic quasi-static loading. The aim is to examine the influence of previous IP cyclic loading on OOP behavior, considering factors such as OOP damage evolution, performance parameters, deformation patterns, and resistance mechanisms. The results show that, in DMIW, the effect of previous IP cyclic loading on the reduction of OOP performance is significantly lower compared to traditional MIW. Furthermore, the fundamental OOP resistance mechanism of DMIW remains unchanged under IP-OOP sequential loading. However, the OOP deformation pattern is altered due to the previous horizontal cracks developed in the masonry units under IP cyclic loading. Finally, a simple bi-linear equation is derived to quantify the effect of the previous IP cyclic loading on the primary OOP performance parameters of the DMIW.