Masonry has historically been one of the most widely used construction
materials. Despite this, there is a lack of computational tools for the analysis of
masonry structures compared with what is available for steel and concrete
structures. One of the main reasons is likely to be found in the peculiar
mechanical behavior of masonry, which shows a small and unpredictable
resistance in tension and a nonlinear inelastic behavior in compression. In
this paper we put forward a constitutive model for masonry based on the
extension to associate path-dependent plasticity of the classical normal, elastic,
no-tension model. This new model allows the onset of fracture and irreversible
crushing of the material and accounts for a wider variety of stress states
within the structure, highlighting the progress of pseudorigid kinematics. The
elastoplastic problem is decomposed into a sequence of nonlinear elastic problems
formulated in variational form, which are solved by searching for the minimum of
a suitable functional via descent methods. The model is implemented in
variational finite element code and validated against analytical solutions and
experimental tests. Applications to realistic cases are presented showing
the capability of the model to reproduce nontrivial cracking and crushing
patterns.
Keywords
masonry, descent methods, energy minimization, unilateral
materials, plasticity