On the modelling of infilled frames through strut models

Infill panels largely affect the seismic response of framed constructions. The wide variety in their mechanical and geometrical features has induced, in the last decades, many different models and assumptions in their analytical representation. In this paper the simplest and more diffuse analytical approach, based on the introduction of equivalent struts, has been checked. Some of the main strut models have been presented and compared as regards the number, the dimensions and the strength to assume for the equivalent strut. The numerical results provided by the considered models by performing a nonlinear static analysis have been checked with reference to two different case-studies, differing to each other for the ratio between the infill and the frame stiffness and strength. The comparison between experimental and numerical data, expressed in terms of stiffness and strength, has pointed out the role of each considered assumption in the effectiveness of the models.