Normal elastic and elastoplastic materials: from a comprehensive approach a mixed method for masonry

The article deals with materials with a constraint on the stress, which must belong to a closed and convex subset of the space of the sec- ond order tensors, called stress range. With particular reference to the case of polyhedral stress ranges, the nonlinear elastic constitutive model and the elastoplastic one are compared to each other and a new ”mixed model” is proposed. The latter may be appropriate in some cases, e.g. for materials un- able to withstand traction. The constitutive models, implemented in the finite element code Mady, are applied to some case studies, and some results are compared with those obtained through the Ansys code.