An experimental and numerical contribution for understanding the in-situ shear behaviour of unreinforced masonry

The assessment and modelling of unreinforced masonry structures require an adequate understanding of masonry behaviour under shear loading. In particular, the behaviour of the interfaces connecting, brick and mortar, are of key importance during seismic actions. This is because the unit-joint interface may act as the main plane of weakness in the masonry composite. It has been observed that the inelastic behaviour of masonry structural elements subjected to shear loading depends largely on this interface behaviour. Hence, different experimental techniques available to observe in-situ or in a laboratory the behaviour of masonry under shear loading are reviewed and a suitable experimental campaign, also employing DIC as optical monitoring system is undertaken and shear tests are performed. After visualisation and discussion of novel displacement and shear strain maps and graphs, the experimental masonry behaviour is replicated via different numerical models based on the finite element approach. Models are used for better characterising the behaviour of the interface between brick and mortar. Further, the main parameters affecting the numerical models are discussed.