Macroelement Model for In-Plane and Out-of-Plane Responses of Masonry Infills in Frame Structures

A new macroelement model is presented in this paper for the simulation of the in-plane (IP) and out-of-plane (OOP) response of infilled frames subjected to seismic actions. The model consists of two diagonal, one horizontal, and one vertical struts. Each strut is represented by two fiber-section beam-column elements. The model is able to capture the arching action of the wall under an OOP load as well as the interaction between the IP and OOP actions. The proposed modeling approach is sufficiently simple and efficient that it can be used for the static or dynamic analysis of an entire structural system. An experimental validation has been carried out. A further numerical study performed with the macroelement model has shown that wall damage due to IP loads can significantly reduce the OOP resistance of the wall, and this influence depends on the slenderness (height/thickness) of the wall. A more slender wall will suffer a more significant loss of OOP resistance.