Homogenization results for elliptic problems in periodically perforated domains with mixed-type boundary conditions

The asymptotic behaviour of a class of elliptic equations with highly oscillating coefficients, in a perforated periodic domain, is analyzed. We consider, in each period, two types of holes and we impose, on their boundaries, a Signorini and, respectively, a Neumann condition. Using the periodic unfolding method, we prove that the limit problem contains two additional terms, a right-hand side term and a “strange” one.