In-plane dynamic crushing of honeycomb. Part II: application to impact

Hönig, Andreas; Stronge, W. J.

doi:10.1016/s0020-7403(02)00061-9

Cited by 71 publications

(21 citation statements)

References 11 publications

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“…Each cell wall is meshed with shell elements (using S4R, a four-node quadrilateral shell element with reduced integration and a large-strain formulation, in ABAQUS), as was similarly done in Hö nig and Stronge (2002b), Ruan et al (2003), and Zheng et al (2005). The main reason for choosing such general purpose shell elements over the simpler Euler-Bernoulli beam elements (B23H in ABAQUS) is that ABAQUS/Explicit was not equipped with the capability for simulating double-sided contact between lines comprising of beam elements (Hö nig and Stronge, 2002b). Each of these shell elements has a set of elemental properties, which include the element length that is 1/10 of the edge length of a regular cell wall and the element thickness that is the same as the random thickness of the cell wall obtained earlier using Eq.…”

Section: Finite Element Analysismentioning

confidence: 99%

Dynamic crushing behavior of honeycomb structures with irregular cell shapes and non-uniform cell wall thickness

Gao

Wang

2007

International Journal of Solids and Structures

137

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Dynamic crushing responses of honeycomb structures having irregular cell shapes and non-uniform cell wall thickness are studied using the Voronoi tessellation technique and the finite element (FE) method. FE models are constructed for such honeycomb structures based on Voronoi diagrams with different degrees of cell shape irregularity and cell wall thickness non-uniformity. The plateau stress, the densification strain energy and the initiation strain are determined using the FE models. Simulation results reveal that the ''X'' and ''V'' shaped deformation modes evident in a perfectly ordered honeycomb at low or moderate impact velocities are disrupted as cell shapes become irregular and/or cell wall thickness gets non-uniform. The ''I'' shaped deformation mode is clearly seen in all honeycomb structures at high impact velocities. Both the plateau stress and the densification strain energy are found to decrease as the degree of cell shape irregularity or the degree of cell wall thickness non-uniformity increases, with the weakening effect induced by the presence of non-uniform cell wall thickness being more significant. When the two types of imperfections co-exist in a honeycomb structure, the interaction between them is seen to exhibit a complicated pattern and to have a nonlinear effect on both the plateau stress and the densification strain energy. It is also found that stress waves propagate faster in a honeycomb structure having irregular cell shapes and slower in a honeycomb structure having non-uniform cell wall thickness than in a perfectly ordered honeycomb. Finally, the strain hardening of the cell wall material is seen to have a strengthening effect on the plateau stress, which is more significant for perfectly ordered honeycombs than for imperfect honeycomb structures.

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Section: Finite Element Analysismentioning

confidence: 99%

Dynamic crushing behavior of honeycomb structures with irregular cell shapes and non-uniform cell wall thickness

Gao

Wang

2007

International Journal of Solids and Structures

137

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“…) and [29] (drop weig ht test, strain rate 500 s -1 ). Dynamic in-plane compression testing on polycarbonate honeycomb is reported in [30], where an increase in crush strength was also observed.…”

Section: Introductionmentioning

confidence: 99%

Strain rate effects in phenolic composites and phenolic-impregnated honeycomb structures

Heimbs¹,

Schmeer

Middendorf³

et al. 2007

Composites Science and Technology

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The influenc e of the loading rate on the material behaviour of glass fibre reinforced phenolic composites and phenolic resin-impregnated aramid paper (Nomex ® ) honeycomb structures was investigated experimentally. The composite specimens were made of woven fabric plies and loaded in tension and shear. Two types of Nomex ® honeycomb specimens (hexagonal and over-expanded) were loaded in uniaxial compression in all three material directions. Quasi-static test results were compared to dynamic test data obtained on a drop tower, where different strain rates from 10 s -1 to 300 s -1 were tested.The glass/phenolic composite material showed a remarkable strain rate effect at higher loading rates with over 80% increase in tensile strength. Also for the Nomex ® honeycomb an increase of the stress level of up to 30% was observed. These material characteristics should be taken into account in case of dynamic analysis (e.g. crash, impact) of honeycomb sandwich panels for public transport applications, which are usually made from these phenolic materials.

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“…Drj=Dt þ rjdivv ¼ ÀdivðJÞ þ rb or the Eulerian form vrj=vt þ divðrjv Þ ¼ ÀdivðJÞ þ rb on setting v Ã ¼ 0. Equation (5) can be simplified further to…”

Section: Conservation Governing Equationsmentioning

confidence: 99%

“…It is shown in the previous section that in the absence of any discontinuity, both integral and differential conservation equations are equivalent and there is no specific advantage in using Equation (1) or Equation (5). Consider then the case when a discontinuity appears inside a continuum body.…”

Section: Continua With a Materials Discontinuitymentioning

confidence: 99%