This paper describes a model able to evaluate the effect of masonry panels on reinforced concrete frames subjected to a seismic action. The panel is modelled as an equivalent diagonal element with a bilinear constitutive relation. The efficacy of the model is verified with an hysteretic model which considers some fundamental characteristics of masonry subjected to a seismic action (transitory phase between elastic and elasto-plastic behaviour, stiffness and strength decay, reduction of the hysteresis cycles due to the opening and closing of the cracks). This study shows that the presence of masonry panels causes a different distribution of the seismic action that usually concentrates in the lower floors (with accumulation of the damage in these levels) and the whole structure keeps in the elastic field.
This paper is available in Italian only.