NUMERICAL ANALYSIS OF STRUCTURAL MASONRY PANEL USING MACROMODELING AND SIMPLIFIED MICROMODELING

Resumo

The structural masonry is among the oldest construction techniques, but over time it was replaced by
concrete and steel constructions. Recently, the number of buildings executed in structural masonry is increasing,
mainly due to the social interest housing programs, leading at the same time the increase of the cases of structural
pathologies, highlighting the need of additional studies and research in this area. Unlike frame structures, where
the walls are used only as enclosure elements, in structural masonry the panels are load-bearing structures and can
be represented by some of their 5 possible distinct elements (block, mortar, grout, interface and reinforcement) or
by panels of a single homogenized material. The representation of the panel by distinct elements generates
difficulties but is essential for local analysis of stresses and load distributions in the panels what permit to evaluate
the structural performance of this constructive technique and emergence of the building pathologies (damage and
crack pattern). In this work, the modeling and analysis of a structural masonry panel was carried out using the
Ansys software based in the Finite Element Method (FEM), applying the simplified micromodeling and
macromodeling techniques. The panel was analyzed in a two-dimensional way, being detailed the expressions for
stress and strain that govern the problem, as well as the properties of the equivalent material considering the
orthotropy applied in the macromodeling technique (homogenization). The panel analyzed was detailed as a
structural masonry wall, formed by solid blocks of concrete and having a concrete beam as a supporting element.
For analysis, a linear load was applied to the panel, being evaluated in this work, in a comparative way, the panel,
containing opening and the panel without opening. The panel modeling was performed using the PLANE42
element in state of plane stress, what is bi-linear Lagrange element (4 nodes) and two degrees of freedom per node.
Through the results obtained in this work, it was possible to evaluate that the wall and beam set works in a similar
way to the arch, with compressive stresses on the wall and tensile stresses on the beam being predominant, with a
concentration of stresses also being observed for the area of the panel close to the support. It was also possible to
verify that the presence of the opening in the panel causes a high concentration of tensions at the top and at the
bottom, justifying the use of the joint reinforcement at lintel bearing. When comparing the stress results obtained
between the micromodeling and macromodeling technique, it was observed that the homogenization technique has
convergent results on the global behavior.