Static and dynamic properties of high-density metal honeycombs

Baker, W. E.; Togami, Takuya; Weydert, J.C.

doi:10.1016/s0734-743x(97)00040-7

Cited by 109 publications

(51 citation statements)

References 5 publications

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“…The impact velocity, v was measured by timing the passage of the striker between two light beams, and an elastic wave speed c"5000 m s\ was assumed. The strain gauge calibration was checked dynamically using relation (2). Additionally, the linearity of the system was checked by varying the magnitude of the impact velocity, v .…”

Section: Recording System and Calibrationmentioning

confidence: 99%

High strain rate compressive behaviour of aluminium alloy foams

Deshpande

Fleck

2000

International Journal of Impact Engineering

544

266

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The high strain rate compressive behaviour of two cellular aluminium alloys (Alulight and Duocel) has been investigated using the split Hopkinson pressure bar and direct impact tests. It is found that the dynamic behaviour of these foams is very similar to their quasi-static behaviour. The plateau stress is almost insensitive to strain rate, for strain rates up to 5000 s\ . Deformation is localised in weak bands in the Alulight foam but is spatially uniform for the Duocel foam, over the full range of strain rates 10\ s\ ) )5000 s\ .

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Section: Recording System and Calibrationmentioning

confidence: 99%

High strain rate compressive behaviour of aluminium alloy foams

Deshpande

Fleck

2000

International Journal of Impact Engineering

544

266

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“…Metallic sandwich panels with cellular cores have attracted significant attention for dynamic energy absorption and impact mitigation [Baker et al 1998;Fleck and Deshpande 2004;2005;Rathbun et al 2006;Dharmasena et al 2007b;Liang et al 2007]. During impact with rigid objects, they reduce damage to the structures they protect by core crushing and face sheet stretching at pressures significantly less than those created when an equivalent solid is Keywords: sandwich panels, honeycomb cores, impulse loading, cellular structures.…”

Section: Introductionmentioning

confidence: 99%

“…Recent analytical and numerical studies of edge supported panels subjected to dynamic loading have confirmed that core crushing during distributed impulsive loading does affect impulse transfer [Baker et al 1998;Fleck and Deshpande 2004;2005;Rathbun et al 2006;Tilbrook et al 2006;Dharmasena et al 2007b;Liang et al 2007;]. This crushing behavior depends upon the cell topology, the material used to construct the cells, and the volume fraction of cell material (the core relative density,ρ) [Tilbrook et al 2006;.…”

Section: Introductionmentioning

confidence: 99%

Dynamic compression of square honeycomb structures during underwater impulsive loading

Wadley

Dharmasena

Queheillalt

et al. 2007

JOMMS

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Significant reductions in the fluid structure interaction regulated transfer of impulse occur when sandwich panels with thin (light) front faces are impulsively loaded in water. A combined experimental and computational simulation approach has been used to investigate this phenomenon during the compression of honeycomb core sandwich panels. Square cell honeycomb panels with a core relative density of 5% have been fabricated from 304 stainless steel. Back supported panels have been dynamically loaded in through thickness compression using an explosive sheet to create a plane wave impulse in water. As the impulse was increased, the ratio of transmitted to incident momentum decreased from the Taylor limit of 2, for impulses that only elastically deformed the core, to a value of 1.5, when the peak incident pressure caused inelastic core crushing. This reduction in transmitted impulse was slightly less than that previously observed in similar experiments with a lower strength pyramidal lattice core and, in both cases, was well above the ratio of 0.35 predicted for an unsupported front face. Core collapse was found to occur by plastic buckling under both quasistatic and dynamic conditions. The buckling occurred first at the stationary side of the core, and, in the dynamic case, was initiated by reflection of a plastic wave at the (rigid) back face sheet-web interface. The transmitted stress through the back face sheet during impulse loading depended upon the velocity of the front face, which was determined by the face sheet thickness, the magnitude of the impulse, and the core strength. When the impulse was sufficient to cause web buckling, the dynamic core strength increased with front face velocity. It rose from about 2 times the quasistatic value at a front face initial velocity of 35 m/s to almost 3 times the quasistatic value for an initial front face velocity of 104 m/s. The simulations indicate that this core hardening arises from inertial stabilization of the webs, which delays the onset of their buckling. The simulations also indicate that the peak pressure transmitted to a support structure from the water can be controlled by varying the core relative density. Pressure mitigation factors of more than an order of magnitude appear feasible using low relative density cores. The study reveals that for light front face sandwich panels the core strength has a large effect upon impulse transfer and the loading history applied to support structures.

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“…Metallic sandwich panels with cellular cores have attracted significant attention for dynamic energy absorption and impact mitigation [Baker et al 1998;]. During impact with rigid objects, they reduce damage to the structures they protect by core crushing and face sheet stretching at pressures significantly less than those created when an equivalent solid is Keywords: sandwich panels, honeycomb cores, impulse loading, cellular structures.…”

Section: Introductionmentioning

confidence: 99%

“…Recent analytical and numerical studies of edge supported panels subjected to dynamic loading have confirmed that core crushing during distributed impulsive loading does affect impulse transfer [Baker et al 1998;2006;]. This crushing behavior depends upon the cell topology, the material used to construct the cells, and the volume fraction of cell material (the core relative density,ρ) .…”

Section: Introductionmentioning

confidence: 99%

Untitled

2007

JOMMS

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See inside back cover or http://www.jomms.org for submission guidelines.Regular subscription rate: $500 a year. Polymeric materials often undergo large inhomogeneous deformations at high rates during their use in various impact-resistant energy-absorbing applications. For better design of such structures, a comprehensive understanding of high-rate deformation under various loading modes is essential. In this study, the behavior of polycarbonate was studied during tensile loading at high strain rates, using a splitcollar type split Hopkinson tension bar (SHTB). The effects of varying strain rate, overall imposed strain magnitude and specimen geometry on the mechanical response were examined. The chronological progression of deformation was captured with a high-speed rotating mirror CCD camera. The deformation mechanics were further studied via finite element simulations using the ABAQUS/Explicit code together with a recently developed constitutive model for high-rate behavior of glassy polymers. The mechanisms governing the phenomena of large inhomogeneous elongation, single and double necking, and the effects of material constitutive behavior on the characteristics of tensile deformation are presented.

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Static and dynamic properties of high-density metal honeycombs

Cited by 109 publications

References 5 publications

High strain rate compressive behaviour of aluminium alloy foams

High strain rate compressive behaviour of aluminium alloy foams

Dynamic compression of square honeycomb structures during underwater impulsive loading

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