Fatigue-related damping in some cellular metallic materials

Internal friction in metallic foams and some related cellular structures

“…Most of the results in [16][17][18] fit well to this equation, which is also true for some of our later data [1,2] if only the influence of porosity is considered. As concerns pore size and frequency, the situation is not so simple.…”

“…As concerns pore size and frequency, the situation is not so simple. A very weak sensitivity to pore size was measured for a 316L steel (64% porosity) with average pore sizes from less than 50-425 m (range of amplitudes (2-20) × 10 −4 [1,2]). Also, a steel with two-level porosity [1] did not show a clear influence of frequency of forced vibrations in a range from 10 −4 to 10 3 Hz on damping at low amplitude ε = 5 × 10 −6 .…”

“…In some cases damping might be rather high and attractive for applications taking into account the low density of such materials. An important problem is, however, that under some technical conditions such favourable damping characteristics may be unstable [1,2,[8][9][10].…”

“…For this purpose, it is necessary first to characterise briefly the different cellular solid structures considered, and their general influence on mechanical properties. Some more specific aspects (microplasticity, interference with fatigue damage), and also more experimental details, are included in two separate papers [1,2].…”

Microplasticity effect in low-velocity zone induced by seismic wave

“…The atypical inelasticity in the small-strain range is of interest for both basic and applied science. Microplasticity in metals, alloys, and other solid states is well known (Golovin et al, 2004;Nishino and Asano, 1996). However, in Earth science, there are obvious gaps in this knowledge.…”