Damping in some cellular metalic materials due to microplasticity

The damping capacities of a few porous structures are studied. Damping in porous structures is enhanced by localised stresses in comparison with the corresponding dense materials. A model for mechanical damping in porous materials is suggested for the “microplastic” range of deformation on the basis of statistical mechanics of micro-heterogeneous materials. Two types of heterogeneity are discussed: one-level porosity (direct by sintered powder steels) and two-level porosity (larger pores in carcass with smaller pores).