Effiziente simulation großer mauerwerksstrukturen mit diskreten rissmodellen

In this article, a numerical model for the efficient simulation of large masonry structures with the finite element method is proposed. In the numerical model, a so-called unit cell is used to describe the load carrying behaviour of a representative sample of masonry. This cell is a model in original scale of the masonry bond with the regular arrangement of stone and mortar. The mortar joints act as weak layers leading to crack patterns with preferred horizontal, vertical and diagonal orientation. The unit cell consists of an element patch, in order to describe the respective failure modes with corresponding orientated interface elements. With this finite element mesh, the structural properties of the masonry bond are described macroscopically and geometric properties like the shape of the stones are taken into account. The step-wise failure of the mortar through horizontal and vertical joints is described by a diagonal interface element. Using this method, the high quality of discrete crack models at the meso scale can be combined with the numerical efficiency of classical macromodels. In a first step the numerical model was developed for masonry of square-shaped units under plane stress conditions. Simple geometric adaption in the meshing procedure allows for the unit cell to also be applied to rectangular units.