The mechanical properties and modeling of a sintered hollow sphere steel foam

This paper characterizes mechanical properties of hollow sphere (HS) steel foam, and applies calibrated Deshpande–Fleck plasticity to mechanical simulations of steel foam components. Foamed steel, steel with internal voids, provides enhanced bending rigidity, exceptional energy dissipation, and the potential to mitigate local instability. The experimental characterization of the hollow sphere foam encompasses compressive yield stress and densification strain, compressive plastic Poisson’s ratio, compressive unloading modulus, as well as tensile elastic modulus, tensile unloading modulus, tensile yield stress, tensile fracture strain, and shear yield stress and fracture strain. Since HS steel foam is compressible under triaxial pressure, Deshpande–Fleck plasticity of compressible metals was calibrated and employed in simulations. Plastic Poisson’s ratio, measured in a uniaxial test, is an important metric of foam compressibility, and it affects the response of the foam to multi-axial loadings significantly. This work is part of a larger effort to help develop steel foam as a material with relevance to civil engineering applications.