Predicting models for the evaluation of out-of-plane ultimate load carrying capacity of masonry infill walls

In recent years, the interest in the out-of-plane response of infills has been growing due to the need of limiting damage to these elements, commonly considered as non structural. Different experimental tests and theoretical studies have been carried out on this subject. They highlighted that the slenderness and the boundary conditions of the panel, the mechanical characteristics of the masonry, the stiffness of the surrounding frame elements and the presence of cracks due to prior in-plane damage noticeably affect the out-of-plane carrying capacity of infill walls. In this paper, a review and a comparison of analytical models developed for the assessment of the out-of-plane response of masonry infills is presented. The suitability of selected models to predict the out-of-plane capacity is investigated by means of some experimental results available in the literature. It is concluded that, even though the considered models take into account the main parameters involved (slenderness of the panel, masonry compressive strength, etc.), they are not always able to adequately predict the actual resistance.