A Study of the Out-of-Plane Behaviour of Unreinforced Masonry Walls using a 'Unit and Interaction' Micro-Modelling Approach

Unreinforced masonry (URM) buildings represent, worldwide, a significant part of historic structures but this type of constructions is also widely used in contemporary buildings. This large usage is made despite a well-known vulnerability to lateral solicitations such as the ones namely caused by wind loads or earthquakes.

This paper presents the results of numerical investigations focusing on the mechanical behaviour of unreinforced brick masonry walls subjected to out-of-plane solicitations. The proposed study is carried out using a FE micro-modelling approach (SIMULIA - Dassault System) based on a 'unit and interaction' concept. After an introductive part presenting the subject, the 'unit and interaction' concept is detailed, outlining strong and weak aspects and highlighting the particular interest for studying the effect of out-of-plane solicitations. The paper proposes then a validation of the accuracy of the model to capture the out-of-plane behaviour of masonry components. In this framework, the paper demonstrates the ability of the model to capture horizontal, vertical and diagonal bending behaviour by numerically reproducing experimental devices. Finally, the paper outlines how the results of these preliminary studies would thereafter be used in the analysis of walls subject to two-way bending, where similar failure mechanisms contribute to the overall wall behaviour.