Shear characterization of periodic masonry through numerical and experimental validations at the elementary scale

The literature on periodic masonry provides us with various identification models, with promising numerical validations. However, experimental investigations essential for the practical application of these models are limited. They pose challenges in terms of geometries, unmanageable specimen scales, and even complex boundary conditions, that are nearly impossible to be replicated numerically without the aid of large approximations. Especially, when it comes to experimental validation of strengthened masonry, the number of specimens that are needed for a holistic mechanical characterization is not practically feasible. The current research aims at addressing this limitation, by adopting a masonry specimen at the scale closest to the elementary characteristic cell - the Triplet. Being the smallest scale at which the texture and defining characteristics of a periodic masonry can be sufficiently represented, two masonry configurations, the running bond triplet and the stack bond triplet were realized by intro- ducing vertical mortar joints (head joints) to the standard triplet. The research also adopts a cosserat continuum identification model, which when compared to the classical model gives an opportunity to take into consideration smaller specimen-unit ratios, the micro-deformations, and micro-rotations. In addition to this, FEM models were built and analyzed.The experimental campaign conducted has its focus on shear characterization, where the triplets were tested in a pure shear setup. In addition to the new configurations, the standard triplet was also subjected to these shear stresses, which formed a benchmark for comparisons. The outcome of the experiments allowed the validation of the analytical and numerical models.