ABSTRACT
The considered masonry is a dry assembly of regular full-thickness rectangular blocks of width a and height b, resulting in a periodic internal structure with aligned bed joints and non-aligned head joints. If block size is small with respect to the wall size, a continuum approach can be used, as proposed by Alpa and Monetto in [6] with reference to the incipient inelastic strain mechanisms and subsequently generalized in [7, 8]. Blocks are assumed homogeneous, isotropic and perfectly elastic. Moreover, due to the absence of mortar, the contact between blocks is modelled as unilateral and linearly fnctional. On the assumption of a Cauchy equivalent continuum, the constitutive equations are derived in terms of mean stress a and mean strain e [9] based on the equivalence between the repetitive elementary masonry portion X shown in figure 1 and the equivalent solid one. Separating the elastic and inelastic contributions to the mean strain, they turns out to be expressed as follows:
where K is the compliance isotropic matrix of the compact masonry and £* is the contribution of inelastic mechanisms to the mean strain. The last term is due to fnctional sliding and opening activated at block joints and is evaluated by means of a proper homogenization procedure considering elementary mechanisms of relative displacements between portions of the representative element *4.
