scholarly journals Explosion Resistance of Three-Dimensional Mesoscopic Model of Complex Closed-Cell Aluminum Foam Sandwich Structure Based on Random Generation Algorithm

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhen Wang ◽  
Wen Bin Gu ◽  
Xing Bo Xie ◽  
Qi Yuan ◽  
Yu Tian Chen ◽  
...  

According to the randomness of the spatial distribution and shape of the internal cells of closed-cell foam aluminum and based on the Voronoi algorithm, we use ABAQUS to model the random polyhedrons of pore cells firstly. Then, the algorithm of generating aluminum foam with random pore size and random wall thickness is written by Python and Fortran, and the mesh model of random polyhedral particles and random wall thickness was established by the algorithm read in by TrueGrid software. Finally, the mesh model is impo rted into the LS-DYNA software to remove the random polyhedron part of the pore cell. Compared with the results of scanning electron microscopy and antiknock test, the morphology and properties of the model are close to those of the real aluminum foam material, and the coincidence degree is more than 91.4%. By means of numerical simulation, the mechanism of the wall deformation, destruction of closed-cell aluminum foams, and the rapid attenuation of explosion stress wave after the interference of reflection and transmission of bubbles were studied and revealed. It is found that aluminum foam deformation can be divided into four areas: collapse area, fracture area, plastic deformation area, and elastic deformation region. Therefore, the explosion resistance is directly related to the cell wall thickness and bubble size, and there is an optimal porosity rule for aluminum foam antiknock performance.

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1792 ◽  
Author(s):  
Xiong Wan ◽  
Kai Zhu ◽  
Yanjin Xu ◽  
Baoshuai Han ◽  
Tao Jing

It is well-known that cell morphology plays a vital role in the mechanical properties of the closed-cell aluminum foam. In this work, a three-dimensional (3D) realistic structure was obtained by using the synchrotron X-ray micro-tomography technique and then translated into a numerical model for a further finite-element simulation. In order to investigate the early compressive deformation in the closed-cell aluminum foam, we chose three different strain levels, namely, 0.2% (initiation of plastic strain), 2.8% (propagation of plastic strain band), and 6% (formation of collapse band) to discuss the evolution forms of plastic strain concentration by simulation. We found that the curvature, anisotropy, and distribution of cell volume of adjacent cells played a vital role in the initiation of plastic strain. Furthermore, the phenomenon that plastic strain band propagated along the direction aligned 45° with respect to the orientation of the compression was also investigated in the propagation of the plastic strain band and formation of the collapse band. Finally, the comparison between experimental results and simulation results was performed to illustrate the early location of these three different levels in the whole compressive deformation.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921 ◽  
Author(s):  
Donghui Yang ◽  
Zichen Zhang ◽  
Xueguang Chen ◽  
Xing Han ◽  
Tao Xu ◽  
...  

In this work, closed-cell aluminum foams with 4 wt.% contents of short-cut basalt fibers (BFs) were successful prepared by using the modified melt-foaming method. The pore size of BF-containing aluminum foam and commercially pure aluminum foam was counted. The distribution of BF and its effect on the compressive properties of closed-cell aluminum foams were investigated. The results showed that the pore size of BF-containing aluminum foams was more uniform and smaller. BF mainly existed in three different forms: Some were totally embedded in the cell walls, some protruded from the cell walls, and others penetrated through the cells. Meanwhile, under the present condition, BF-containing aluminum foams possessed higher compressive strength and energy absorption characteristics than commercially pure aluminum foams, and the reasons were discussed.


2017 ◽  
Vol 62 (2) ◽  
pp. 1353-1357
Author(s):  
G.W. Hwang ◽  
J.U. Cho

AbstractAn aluminum foam added with foaming agent, is classified into an open-cell type for heat transfer and a closed-cell type for shock absorption. This study investigates the characteristic on the torsion of aluminum foam for a closed-cell type under impact. The fracture characteristics are investigated through the composite of five types of aluminum foam (the thicknesses of 25, 35, 45, 55 and 65 mm), when applying the torsional moment of impact energy on the junction of a porous structure attached by an adhesive. When applying the impact energy of 100, 200 and 300J, the aluminum foams with thicknesses of 25 mm and 35 mm broke off under all conditions. For the energy over 200J, aluminums thicker than 55 mm continued to be attached. Furthermore, the aluminum specimens with thicknesses of 55 mm and 65 mm that were attached with more than 30% of bonding interface remained, proving that they could maintain bonding interface against impact energy. By comparing the data based on the analysis and test result, an increase in the thickness of specimen leads to the plastic deformation as the stress at the top and bottom of bonding interface moves to the middle by spreading the stress horizontally. Based on this fracture characteristic, this study can provide the data on the destruction and separation of bonding interface and may contribute to the safety design.


Author(s):  
Abdelhakim Aldoshan ◽  
D. P. Mondal ◽  
Sanjeev Khanna

The mechanical behavior of closed-cell aluminum foam composites under different compressive loadings has been investigated. Closed-cell aluminum foam composites made using the liquid metallurgy route were reinforced with multiwalled carbon nanotubes (CNTs) with different concentrations, namely, 1%, 2%, and 3% by weight. The reinforced foams were experimentally tested under dynamic compression using the split Hopkinson pressure bar (SHPB) system over a range of strain rates (up to 2200 s−1). For comparison, aluminum foams were also tested under quasi-static compression. It was observed that closed-cell aluminum foam composites are strain rate sensitive. The mechanical properties of CNT reinforced Al-foams, namely, yield stress, plateau stress, and energy absorption capacity are significantly higher than that of monolithic Al-foam under both low and high strain rates.


1998 ◽  
Vol 521 ◽  
Author(s):  
Joachim L. Grenestedt

ABSTRACTThe mechanical properties of cellular solids, or solid foams, is affected by “imperfections” such as wavy distortions of cell walls, variations in cell wall thickness, non-uniform cell shape, etc. The present paper is focused mainly on elastic stiffnesses of closed cell cellular solids. A “perfect” model is first discussed and shown to predict the behavior of PVC foams well. However, this model over-estimates the stiffnesses of aluminum foams. The relatively poor properties of the aluminum foam are believed to be caused by imperfections in the cells. The main body of the paper focuses on modeling different kinds of imperfections, and analyzing their impact on foam properties.


MRS Bulletin ◽  
2003 ◽  
Vol 28 (4) ◽  
pp. 284-289 ◽  
Author(s):  
E. Maire ◽  
A. Elmoutaouakkil ◽  
A. Fazekas ◽  
L. Salvo

AbstractThe use of microtomography to study the structure and especially the deformation modes of cellular solids is reviewed in this article. First, the technique is described in detail. Examples illustrating the power of the coupling ofin situdeformation with three-dimensional (3D) imaging, drawn from the recent literature and the authors' own work, are then given. The most detailed example is the study of the deformation modes of several samples made of different aluminum foams. Four kinds of closed-cell foams were investigated, corresponding to different routes available today for their manufacture. The initial macrostructure was quantified using the 3D images combined with 3D granulometry, allowing retrieval of pertinent information about the cell size and the wall and strut thicknesses. The global behavior exhibited by the foams during thein situcompression experiments was shown to vary from one brand of material to another. Some of these variations can be explained by differences in the known microstructure and the measured macrostructure of the samples.


2017 ◽  
Vol 748 ◽  
pp. 173-180
Author(s):  
Jing Wang ◽  
Zan Zhang ◽  
Jian Ding ◽  
Chuan Rong Qiu ◽  
Xing Chuan Xia ◽  
...  

Closed-cell aluminum foam with different percentages of Cu was prepared by melt foaming method.The effect of Cu element on the quasi-static compressive properties of aluminum foam was investigated, both under as-cast and heat-treated conditions. The results showed that Cu element distributed in cell wall matrix mainly in the forms of Al-Cu solid solutions and AlCu3, Al6.1Cu1.2Ti2.7 intermetallics. Meanwhile, Cu-containing foams possessed much higher compressive strength than the commercially pure aluminum foams. Additionally, proper heat treatment could further improve the yield strength of Cu-containing foams and the effect of aging treatment was more obvious than the homogenizing heat treatment under the present conditions and the reasons were discussed.


2013 ◽  
Vol 711 ◽  
pp. 195-198
Author(s):  
Suthiphong Sopha ◽  
Santirat Nansa-Arang ◽  
Prachya Peasura

This research was to study the synthesis of aluminum foam with pure aluminum and its mechanical properties. The synthesis varied at 1% - 5% of TiH2 and mixed with 99.7 % aluminum powder size of 44 µm. then compressed by hydraulic at 25, 30 and 35 tons in the diameter 27 mm, high 60 mm molded. The Aluminum foams were produced by using heat treatment at 800 °C for 10 minutes then cool to room temperature and tested its mechanical properties. The results showed that aluminum foams which lowest bulk density (0.958 g/cm3) was 2% TiH2 synthesized, compressed at 35 tons and highest bulk density (1.393 g/cm3) was 1% TiH2 synthesized, compressed at 25 tons. Moreover, the highest compressive strength (847 kg/cm2) showed at 2% TiH2 synthesized and compressed at 35 tons. Thus, this research contributes to a body of knowledge that informs the application of aluminum foam.


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