UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

On the dynamic mechanical properties of open-cell metal foams - A re-assessment of the 'simple-shock theory'

Tan, PJ; Reid, SR; Harrigan, JJ; (2012) On the dynamic mechanical properties of open-cell metal foams - A re-assessment of the 'simple-shock theory'. International Journal of Solids and Structures , 49 (19-20) 2744 - 2753. 10.1016/j.ijsolstr.2012.03.026. Green open access

[thumbnail of 1362720.pdf]
Preview
PDF
1362720.pdf

Download (1MB)

Abstract

Metal foams are increasingly used for energy absorption especially in lightweight structures and to resist blast and impact loads. This requires an understanding of the dynamic response of these materials for modelling purposes. As a supplement to Tan et al., 2005a and Tan et al., 2005b, hereinafter referred to as T–L for brevity, this paper provides experimental data for the dynamic mechanical properties of open-cell Duocel® foams having a three-dimensional (3D) distribution of cells. These confirm significant enhancement of the foam’s compressive strength, accompanied by changes in their deformation pattern in certain loading régimes, particularly what has come to be described as the ‘shock’ régime by Zheng et al. (2012). This paper examines experimentally, in a similar fashion as T–L, how the structural response of the individual cell walls is affected by cell-shape anisotropy at the cell (meso)-scale and how this, in turn, alters the pattern of cell crushing and the dynamic, mechanical properties. The distinctive role of cell microinertia and ‘shock’ formation are discussed in relation to the mechanical properties measured for these 3D cylindrical specimens. For consistency the same procedures described in T–L are used. The features identified are shown to be consistent with those observed in finite-element simulations of two-dimensional (2D) honeycombs as estimated by the one-dimensional (1D) steady-shock theory summarised in T–L. The different deformation patterns that develop in the various loading régimes are categorised according to the compression rate/impact speed. Critical values of impact velocity, corresponding to the transition from one pattern to the other, are quantified and predictive formulae for the compressive uniaxial strengths in the directions of two of the principal axes of the material in each loading régime are derived and discussed. The accuracy of the predictive formula in T–L is shown to critically depend on the ‘densification strain’ of the foam specimens. This parameter and the discussion that follows could assist the formulation and validation of alternative theoretical/computational models on the dynamic deformation of such materials.

Type: Article
Title: On the dynamic mechanical properties of open-cell metal foams - A re-assessment of the 'simple-shock theory'
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.ijsolstr.2012.03.026
Publisher version: http://dx.doi.org/10.1016/j.ijsolstr.2012.03.026
Language: English
Additional information: This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keywords: Duocel (R) foam, Dynamic properties, Strain rate, Microinertia, Densification strain, Simple shock theory
UCL classification: UCL
UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering
URI: https://discovery.ucl.ac.uk/id/eprint/1362720
Downloads since deposit
429Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item