Luigi Gambarotta - Academia.edu (original) (raw)
Papers by Luigi Gambarotta
Keywords: layered materials, damage, strain localization, second order homogenization.
ABSTRACT OverviewDamage in quasi-brittle materials takes place progressively with a nonlinear res... more ABSTRACT OverviewDamage in quasi-brittle materials takes place progressively with a nonlinear response and greater strength under compression than tension. This damage behavior may be interpreted as an effect of micro-crack nucleation and growth inside an elastic matrix. Because these materials sustain mainly compressive stresses, the resulting stress field in the microstructure turns out to be compressive and the opposite edges of the micro-cracks are closed. Because of the roughness of the micro-crack edges, their contact is characterized by friction that is coupled with damage mechanisms. Consequently, the mechanical response of these materials to compressive stress states is nonlinear and dissipative due to the simultaneous presence of two coupled deformation processes consisting of the progressive propagation of micro-cracks together with the frictional sliding between the crack faces. This interpretation of the micro-crack effects on the mechanisms of inelastic deformation makes c ...
An incremental-iterative procedure for the non-linear analysis of multi-span masonry arch bridges... more An incremental-iterative procedure for the non-linear analysis of multi-span masonry arch bridges is developed and implemented by standard programming of a commercial F.E. code assuming masonry no tensile resistant (NTR) and perfectly elasto-plastic in compression. The procedure is applied to different arch geometries pointing out the effect on the collapse mechanism of the arch geometric parameters and of the material mechanical ones. Twin-and three-span models are studied and compared to a classical single-span assessment method; the elasto-plastic response of masonry is found to have great effect on the limit load of both shallow and deep arches, while abutment compliance and interaction between adjacent spans has to be taken into account for shallow arch bridges only, being of minor importance for deep arches.
Keywords: layered materials, damage, strain localization, second order homogenization.
ABSTRACT OverviewDamage in quasi-brittle materials takes place progressively with a nonlinear res... more ABSTRACT OverviewDamage in quasi-brittle materials takes place progressively with a nonlinear response and greater strength under compression than tension. This damage behavior may be interpreted as an effect of micro-crack nucleation and growth inside an elastic matrix. Because these materials sustain mainly compressive stresses, the resulting stress field in the microstructure turns out to be compressive and the opposite edges of the micro-cracks are closed. Because of the roughness of the micro-crack edges, their contact is characterized by friction that is coupled with damage mechanisms. Consequently, the mechanical response of these materials to compressive stress states is nonlinear and dissipative due to the simultaneous presence of two coupled deformation processes consisting of the progressive propagation of micro-cracks together with the frictional sliding between the crack faces. This interpretation of the micro-crack effects on the mechanisms of inelastic deformation makes c ...
An incremental-iterative procedure for the non-linear analysis of multi-span masonry arch bridges... more An incremental-iterative procedure for the non-linear analysis of multi-span masonry arch bridges is developed and implemented by standard programming of a commercial F.E. code assuming masonry no tensile resistant (NTR) and perfectly elasto-plastic in compression. The procedure is applied to different arch geometries pointing out the effect on the collapse mechanism of the arch geometric parameters and of the material mechanical ones. Twin-and three-span models are studied and compared to a classical single-span assessment method; the elasto-plastic response of masonry is found to have great effect on the limit load of both shallow and deep arches, while abutment compliance and interaction between adjacent spans has to be taken into account for shallow arch bridges only, being of minor importance for deep arches.