Dynamic behaviour of cork and cork-filled aluminium tubes: Numerical simulation and innovative applications

Holzforschung ◽  
2007 ◽  
Vol 61 (4) ◽  
pp. 400-405 ◽  
Author(s):  
Celina Pires Gameiro ◽  
José Cirne ◽  
Victor Miranda ◽  
Joaquim Pinho-da-Cruz ◽  
Filipe Teixeira-Dias

Abstract Cork is a unique and complex natural cellular material with many industrial applications. The purpose of this paper is to explore a new application field for the use of micro-agglomerate cork as an energy-absorbing medium. A numerical study on the energy absorption capabilities of square and circular cork-filled aluminium tubes with a width or diameter of 80 mm, length of 300 mm and variable thickness was performed with the finite element method code LS-DYNA™. The tubes were impacted uniaxially at 10 and 15 m s-1. The same analysis was carried out on aluminium foam-filled tubes. The results demonstrate that cork filling leads to a considerable increase in the energy absorbed for both section geometries, and that tube thickness plays an important role in the deformation modes and energy absorption. The investigation revealed better results for aluminium foam-filled structures, but demonstrated that micro-agglomerate cork has high potential as an energy-absorbing medium in crash protection applications.

2014 ◽  
Vol 620 ◽  
pp. 413-416 ◽  
Author(s):  
Yang An ◽  
Chun Hui Yang ◽  
Peter Hodgson

In the study, the strengthening effect of aluminium foam in thin-walled aluminium tubes subject to bending load in investigated experimentally and numerically. Bending tests are conducted on foam filler, hollow tube and foam-filled tube. The finite element method is used as well to get deeper insight into the crush failure modes via focusing on the influence from wall thickness of the tube. The obtained information is useful to optimally design foam-filled tubes as energy absorbing devices in automotive engineering. The optimisation results can be implemented to find an optimum foam-filled tube that absorbs the same energy as the optimal hollow tube but with much less weight.


2011 ◽  
Vol 213 ◽  
pp. 88-92 ◽  
Author(s):  
Qing Chun Wang ◽  
Hao Long Niu ◽  
Guo Quan Wang ◽  
Yu Xin Wang

Different aluminum foam filling lengths were used to increase the bending energy absorbing capacity of the popularly used hat sections. Bending energy-absorption performance of the thin-walled tubes was numerically studied by explicit non-linear software LS-Dyna. First empty hat section subjected to quasi-static bending crushing was simulated, then structures with different aluminium foam filling lengths were calculated, finally energy absorption capacity of these structures were compared. Calculation results showed that, the internal energy absorbed and mass specific energy absorption capacity of foam filled thin walled structures were increased significantly compared to the empty sections. The reason of the improvement was mainly due to the contact of the aluminium foam and the structure. Aluminium foam filling is a promising method for improving lateral energy absorbing capacity of thin-walled sections.


2012 ◽  
Vol 585 ◽  
pp. 34-38 ◽  
Author(s):  
Manmohan Dass Goel ◽  
Laxminarayan Krishnappa

Modeling and numerical simulation of aluminum foam filled square tubes under axial impact loading is presented. The foam-filled thin-walled square tubes are modeled as shell wherein, foam core is modeled by incorporating visco-elastic plastic foam model in Altair® RADIOSS. Deformation and energy absorption studies with single, bi-tubular, and multi-tube structure with and without aluminum foam core are carried out for assessing its effectiveness in crashworthiness under the identical conditions. It is observed that the multi-tube structure with foam core modify the deformation modes considerably and results in substantial increase in energy absorption capacity in comparison with the single and multi-tube without foam core. Moreover, the multi-tube foam filled structure shows complicated deformation modes due to the significant effect of stress wave propagation. This study will help automotive industry to design superior crashworthy components with multi-tube foam filled structures and will reduce the experimental trials by conducting the numerical simulations.


2021 ◽  
Vol 15 ◽  
pp. 159-164
Author(s):  
Fauzan Djamaluddin

In this study, the researcher carried out a comparative investigation of the crashworthy features of different tubular structures with a quasi-static three bending point, like the foam-filled two and tri circular tube structures. Energy absorption capacities and failure modes of different structures are also studied. Furthermore, the general characteristics are investigated and compared for instance the energy absorption, specific energy absorption and energy-absorbing effectiveness for determining the potential structural components that can be used in the field of vehicle engineering. Experimental results indicated that under the bending conditions, the tri foam-filled structures were higher crashworthiness behaviour than the two foam-filled circular structures. Therefore, this study recommended the use of crashworthy structures, such as foam-filled tri circular tubes due to the increased bending resistance and energy-absorbing effectiveness.


2019 ◽  
Vol 11 (1) ◽  
pp. 41-68 ◽  
Author(s):  
Chukwuemeke William Isaac

The dynamic oblique crushing of circular thin-walled tubes with the presence of non-propagating crack was investigated numerically. The material considered was strain rate sensitive with crack located at the distal end of the tube. Major crashworthiness parameters were obtained and the analysis of the structural response for idealized and finite element crushed thin-walled tubes was also carried out. The study shows that crack initiation on energy absorbing tubes increase their crushing force efficiency under oblique impact, decrease their crushing force efficiency under axial impact and reduce their crashworthiness performance such as the energy absorption capacity and specific energy absorption under axial and oblique impact. Results of the crashworthiness parameters, deformation modes, damage morphology, stress–strain relations, absorption energy characteristics and crushing force-displacement history were obtained. Furthermore, the numerical study reveals both the desirable and undesirable consequence of crack on the overall crashworthiness performance of energy absorbing circular thin-walled tubes.


Author(s):  
Muhammad Ali ◽  
Eboreime Ohioma ◽  
Khairul Alam

Square tubes are primarily used in automotive structures to absorb energy in the event of an accident. The energy absorption capacity of these structural members depends on several parameters such as tube material, wall thickness, axial length, deformation modes, locking strain, crushing stress, etc. In this paper, the work presented is a continuation of research conducted on exploring the effects of the introduction of cellular core in tubular structures under axial compressive loading. Here, the crushing response of composite cellular core tube was numerically studied using ABAQUS/Explicit module. The energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, crushing stroke, and energy curves were discussed. The composite cellular core tube shows promise for improving the crashworthiness of automobiles.


2012 ◽  
Vol 152-154 ◽  
pp. 436-439 ◽  
Author(s):  
Yang An ◽  
Cui E Wen ◽  
Peter D. Hodgson ◽  
Chun Hui Yang

The effect of foam fillers on the impact behaviour and energy absorption of an aluminium tube is investigated. Both experimental test and computational simulation are employed in current study. For comparison, hollow tubes and foams are also tested, respectively. Foam filler is found to be ineffective in increasing the crushing loads of the composite tubes over the simple superposition of the crushing loads of hollow tube and foam. Also, foam filler increases the tendency for the concertina mode of folding. The foam fillers of tubes additionally result in increasing the SAE values over those of hollow tubes.


2014 ◽  
Vol 592-594 ◽  
pp. 1109-1113 ◽  
Author(s):  
Dipen Kumar Rajak ◽  
L.A. Kumaraswamidhas ◽  
S. Das

The focus of this paper is to study the energy absorption characteristics of aluminium foam filled sections. The energy absorption capability of square mild steel foam filled and empty samples to absorbed mechanical energy have been estimated according to the results from the compressive tests. The tests were performed on the universal testing machine .The experimental results shows that aluminium foam filled sections feature have good energy absorption at various strain rates from 10-3/s to 10/s.


2015 ◽  
Vol 07 (04) ◽  
pp. 1550060 ◽  
Author(s):  
Yanfei Xiang ◽  
Min Wang ◽  
Tongxi Yu ◽  
Liming Yang

Based on a systematic investigation on the experimental, theoretical and numerical results on various tubes under axial compression/impact including our own tests, a set of key performance indicators (KPIs) for assessing and comparing the energy absorbing performance of tubular structures with various configurations is proposed, so as to guide the design of energy absorbers whilst to facilitate parameter optimization. The five KPIs proposed on the basis of mechanical analyses are effective stroke ratio (ESR), nondimensional load-carrying capacity (NLC), specific energy absorption (SEA), effectiveness of energy absorption (EEA) and undulation of load-carrying capacity (ULC). Moreover, by considering the influence of foam filling, these five KPIs are also modified and extended to the foam-filled tubes. The paper presents a series of diagrams to compare the energy absorbing performance of various tubes in terms of the five KPIs as described above. It transpires that the energy absorption performance of circular tubes is superior to that of square tubes. It is also confirmed that the mass of foam fillers results in reductions of SEA and EEA, though foam fillers will greatly improve the NLC of empty tubes. The novelty of the present study is displayed on the following aspects: (1) uniquely defining the effective stroke by the maximum point of "energy efficiency" f so as to avoid ambiguity which appeared in the literature; (2) instead of a single indicator such as SEA, proposing a set of five KPIs to comprehensively assess the performance of energy absorbers and (3) validating the usefulness of the proposed KPIs by comparing the performance of various tubular structures used as energy absorbers.


Author(s):  
Muhammad Ali ◽  
Khairul Alam ◽  
Eboreime Ohioma

Axial members are commonly used in automotive structures and are responsible for absorbing significant portion of impact energy in the event of an accident. This study was conducted to investigate the effects of inclusion of functionally graded cellular structures in thin walled members under compressive axial loading. A compact functionally graded cellular structure was introduced inside a 352 mm long square tube with side length and wall thickness of 74 mm and 3.048 mm, respectively. The tube wall material was aluminum. The cellular structure’s geometry was observed in the cross-section of a banana peel that has a specific graded cellular packing in a confined space. This packing enables the peel to protect the internal soft core from external impacts. The same cellular pattern was used to construct the structure in present study. The study was conducted using non-linear finite element analysis in ABAQUS. The hybrid structure (tube and graded cellular structure) was fixed on one side and on the other (free end) side, was struck by a rigid mass of 300 Kg travelling at a velocity of 35 mph (15.64 m/s) along the axis of the square tube and perpendicular to the in-plane direction of the graded cellular structure. The tube and cell walls were discretized using reduced integration, hourglass control, 4 nodes, and hexahedral shell elements. The impact plate was modeled with 4 node rigid shell elements. General contact conditions were applied to define surface interaction among graded structure, square tube, and rigid plate. The parameters governing the energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, and energy curves, were evaluated. The results showed that the inclusion of graded cellular structure increased the energy absorption capacity of the square tube by 41.06%. The graded structure underwent progressive stepwise, layer by layer, crushing mode and provided lateral stability to the square tube thus delaying local tube wall collapse and promoting outward convex localized folds on the tube’s periphery as compared to highly localized and compact deformation modes that are typically observed in an empty square tube under axial compressive loading. The variation in deformation mode, large contact areas, presence of graded cellular structure resulted in enhanced stiffness of the hybrid structure, and therefore, high energy absorption by the structure. The results of this preliminary study show a potential of functionally graded cellular materials to significantly improve the energy absorbing capacities of thin walled members under axial loading by altering member’s crushing deformation modes.


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