Flexural bearing capacity and related ductility demand for masonry sections under nonlinear constitutive law

This paper aims at examining the maximum bearing capacity of rectangular masonry cross-sections subjected to eccentric compression, by assuming a nonlinear constitutive law characterized by two parameters defining stress-strain curve of the material. The variation of these parameters permits us to represent a wide variety of materials; therefore the ductility required of these materials in order for a section to achieve the maximum bending moment compatible with an average normal stress is also determined. The proposed approach can be utilized to evaluate the safety condition of masonry bearing walls, like those characterizing buildings of historical and/or monumental interest, for which the stress state can become dangerous because of eccentricity in the loads or due to horizontal seismic forces. Some experimental tests confirm the reliability of the proposed procedure.