University of Naples Federico II, Department of Structural Engineering, Naples, Italy


Simplified non-linear seismic analysis methods of standard masonry buildings are typically based on the macro-element discretization of walls with openings. Among different macro-elements, spandrel panels (namely the horizontal structural elements) play a fundamental role in the seismic response, since they affect both load-bearing and deformation capacity of the walls.
The paper deals with the closed-form solving of sectional equilibrium equations to evaluate the flexural strength of spandrel panels for the stress-strain relationships provided by EC6 and by Turnšek and ?a?ovi?. The influence of strain ductility on the ultimate flexural strength is also investigated by means of two-dimensional evolutionary domains. Finally, the proposed equations are compared to those available in the literature and in seismic codes. It is showed that the novel theoretical formulae allow to account for more real characteristics in the estimation of the bending moment capacity of masonry spandrels.

Key words
unreinforced masonry, spandrel panels, strength domains, strain ductility