Summarization: In this article a numerical approach is proposed for the investigation of composite materials, like masonry. A number of simulations of a nonlinear, heterogeneous microstructure with gradually increasing loading, are considered. Average stress and stiffness are also derived. Then, this information is incorporated in databases, and a metamodel is created based on the data and used in an overall macroscopic analysis. On the micro scale, a classical plasticity model for masonry or a unilateral contact law representing a potential crack are considered. A satisfactory comparison between the proposed models and direct macroscopic models arises, indicating that the method can be used for an initial, quick assessment of the failure o...