Masonry is a composite material, whose behavior is strongly influenced by the presence of vertical and horizontal mortar joints, weak elements along which the shear failure usually occurs. The scope of the present work was to investigate factors that could affect the shear-sliding behavior of masonry, by performing numerical simulations of triplet tests conducted on calcium silicate brick masonry specimens with two different bond patterns. In the numerical analyses, a simplified micro-modeling strategy was adopted. A composite interface model was used, including a tension cut-off, a Coulomb friction criterion and a compressive cap. The numerical models were validated through comparisons with results from experimental tests, in terms of failure load, post-peak behavior and specimen deformability. Moreover, factors that could influence the shear-sliding behavior of masonry were analyzed by performing parametric studies. The simplified-micro modeling confirmed to be a very efficient strategy to capture the nonlinear behavior of masonry.