Evaluation of the effect of the strain rate on the compressive response of a closed-cell aluminium foam using the split Hopkinson pressure bar test

Abstract

Evaluation of the effect of the strain rate on the compressive response of a closed-cell aluminium foam using the split Hopkinson pressure bar test Citation for published version: Irausquín, I, Pérez-Castellanos, JL, Miranda, V & Teixeira-Dias, F 2013, 'Evaluation of the effect of the strain rate on the compressive response of a closed-cell aluminium foam using the split Hopkinson pressure bar test', Materials and Design, vol. 47, pp. 698-705. https://doi.Evaluation of the effect of the strain rate on the compressive response of a closedcell aluminium foam using the split Hopkinson pressure bar test I. Irausquín, J.L. Pérez-Castellanos, V. Miranda, F. Teixeira-Dias PII: S0261-3069(12)00879-5 DOI: http://dx.Please cite this article as: Irausquín, I., Pérez-Castellanos, J.L., Miranda, V., Teixeira-Dias, F., Evaluation of the effect of the strain rate on the compressive response of a closed-cell aluminium foam using the split Hopkinson pressure bar test, Materials and Design (2012), doi: http://dx. AbstractThe research here presented is focused on the evaluation of the dynamic behaviour of a closed-cell aluminium foam using the split Hopkinson pressure bar (SHPB) test. On a first approach, the influence of the material of the bars was studied and, as a consequence, polymethylmethacrylate (PMMA) was chosen as the most suitable material to be used in the bars and striker to test the specific aluminium foam considered. This set of bars was manufactured and several dynamic compression tests were carried out. The corresponding stress-strain behaviour was obtained and the dependence of mechanical parameters of the aluminium foam Alporas 10% on the strain rate was thoroughly analysed. It was possible to conclude that the material exhibits significant strain rate sensitivity, within the tested range of strain rates. The range of strain rate values where the compressive behaviour of the foam is different was also determined.

A 3D mesoscopic model for the closed-cell metallic foams subjected to static and dynamic loadings

“…It can be seen that the dynamic strength and the dynamic plateau stress increase with the increase of strain rate. The numerical results are consistent with the test observations [28] at the strain rates of 5 Â 10 2 s À1 and 9 Â 10 2 s À1 . It can be concluded that the numerical model presented in this paper can give reliable predictions of closed-cell aluminum foams subjected to high strain rates.…”

“…The pore size, R min and R max , is 0.9 mm and 3.8 mm. The average pore size is 2.6 mm and the pores ratio is 87.1%, according to the test [28]. The computational parameters for the cell-wall and the air are the same as in Section 4.1.…”

Indentation of aluminium foam at low velocity

“…To show the relationship between the normalized plateau force and the loading velocity, the dynamic plateau forces diveded by quasi-stiac value of all specimens are plotted in Fig. 8, as well as the data from Irausquin et al [7] They evaluated the dynamic behaviour of closed-cell aluminum foam ALPORAS 10% using SHPB. In both our tests and Irausquin's tests, there is a significant increase in the specific plateau forces with the increasing velocity between 10 m/s∼30 m/s.…”

“…On the other hand, according to Gibson and Ashby [8], Dashpande and Fleck's [6] research, the contribution of gas trapped in cells is so small as to be negligible for this increase. Microinertia effects of the cell walls [7,9] or the plastic wave [10] may cause this phenomenon. Further discussion will be conducted in FEM analysis.…”

Investigation on dynamic penetration of closed-cell aluminium foam using in situ deceleration measurement

“…In SHPB test, depending on the bar materials and configurations, different strain rates were obtained and seek to achieve different objectives. Viscoelastic bar [11], magnesium alloy bar [12], and hollow aluminium tube bar [13] were used as Hopkinson pressure bar to match the low mechanical impedance of closed-cell aluminium foams and increased the amplitude of the strain signal measured by the strain gauges attached to the bar. To overcome the small specimen and small strain level conducted using SHPB, a novel modified SHPB configuration [14] used 50 mm diameter aluminium tubular bar with long pre-stress bar that replaced the striker bar that was typically used in SHPB test to obtain a specimen strain up to 50% due to the generated longduration pulse.…”