Masonry micromodels using high order 3D elements

Abstract

Many European heritage and modern buildings have a very high seismic vulnerability due to their masonry-based structural system. Although these structures have a low capacity to resist tension or shear stresses, even nowadays some new buildings are using these materials as structural system in many seismic areas. The main objective of this paper is the use of high order ANSYS code 3D elements in the numerical modelling of masonry structures. For this purpose, FE models corresponding to standard tests were made and calibrated using results of experimental tests. In particular, this document will analyze the resistant behavior to uniaxial and diagonal compression in brick samples. The numerical micromodel has been developed using non-linear hexaedrical 8 and 20 nodes tridimensional elements to represent brick and mortar, such as solid185 and solid186, in contrast to traditional FE models which use element solid65 as finite element to represent masonry behavior. Drucker-Prager and Rankine models have been used to study the compression-tension failure surface, adding a linear hardening-softening-dilatation behavior. Moreover, fracture-energies based cohesive zones have been added to contacts between mortar and bricks, in order to allow debonding failure between these two materials. These modelling methods prove to be a valid technique to simulate brick masonry behavior according to experimental results and will be used as a base to develop future parametric FEM analysis to study TRM reinforced masonry specimens.