scholarly journals Torsion Property of the Structure Bonded Aluminum Foam Due to Impact

2017 ◽  
Vol 62 (2) ◽  
pp. 1353-1357
Author(s):  
G.W. Hwang ◽  
J.U. Cho
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Bonding Interface ◽  
Cell Type ◽  
Aluminum Foams ◽  
Fracture Characteristics ◽  
Foaming Agent ◽  
Closed Cell ◽  
The Impact ◽  
Torsion Property

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.

scholarly journals Experimental Study on the Impact Resistance of Closed-Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xiwu Zhou ◽  
Wen Zhang ◽  
Xiangyu Wang ◽  
Wenchao Zhang ◽  
Meng Zhan
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Impact Force ◽  
Experimental Testing ◽  
Test System ◽  
Protective Effects ◽  
Lateral Impact ◽  
Cumulative Impact ◽  
Closed Cell ◽  
The Impact

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.

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 ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Aluminum Foam ◽  
Three Dimensional ◽  
Coincidence Degree ◽  
Aluminum Foams ◽  
Polyhedral Particles ◽  
Mesh Model ◽  
Closed Cell ◽  
Wall Deformation ◽  
Deformation Area

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.

scholarly journals Study on Concrete Pier Impact Performance after Implementing Equal Cross-Section Stainless Steel with Protection from Closed-Cell Aluminum Foam

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiwu Zhou ◽  
Honglong Zhang ◽  
Wenchao Zhang ◽  
Guoxue Zhang
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Aluminum Foam ◽  
Bridge Piers ◽  
Concrete Bridge ◽  
Reinforced Concrete Bridge ◽  
Impact Forces ◽  
Closed Cell ◽  
Steel Bars ◽  
The Impact

In the present study, in order to examine the impact performances of ordinary reinforced concrete bridge piers which have been replaced by stainless-steel bars of equal cross-sections under the protective condition of anticollision material, the impact dynamic responses of the ordinary reinforced concrete bridge piers, with replacements under the protection of closed-cell aluminum foam, were compared and analyzed using an ultrahigh drop hammer impact test system. The results showed that when the impact velocity was small (for example, less than 1.42 M/s), after the implementation of equal cross-sectional replacements, the closed-cell aluminum foam had been in an elastic or yield stage. During that stage, the impact forces of the stainless-steel reinforced concrete piers were larger than those of the ordinary reinforced concrete piers, and the relative ratios were stable at approximately 28 to 34%. In addition, the relative ratios of the displacements at the tops of the components were also found to be stable at approximately 22%, and the change rates of the concrete ultrasonic damages were approximately the same. However, when the impact forces had increased (for example, more than 1.67 m/s), the closed-cell aluminum foam entered a densification stage, and the peak impact force ratios decreased sharply. It was also observed that the relative peak displacement ratios at the tops of the components displayed increasing trends, and the change rates of the concrete ultrasonic damages had displayed major flux. Therefore, the replacement of the ordinary piers with stainless-steel bars had increased the possibility of shear failures.

scholarly journals Quasi-Static Compression Deformation and Energy Absorption Characteristics of Basalt Fiber-Containing Closed-Cell Aluminum Foam

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921 ◽  
Author(s):  
Donghui Yang ◽  
Zichen Zhang ◽  
Xueguang Chen ◽  
Xing Han ◽  
Tao Xu ◽  
...  
Keyword(s):  
Pore Size ◽  
Energy Absorption ◽  
Cell Walls ◽  
Aluminum Foam ◽  
Pure Aluminum ◽  
Present Condition ◽  
Aluminum Foams ◽  
Commercially Pure ◽  
Closed Cell ◽  
Absorption Characteristics

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.

Influence of Gravity and Mold Shape on Molding of Aluminum Foams

2014 ◽  
Vol 875-877 ◽  
pp. 1280-1284
Author(s):  
Masanori Shiomi ◽  
Tomohiro Fukaya
Keyword(s):  
Melting Point ◽  
Aluminum Foam ◽  
Large Diameter ◽  
Mold Filling ◽  
Light Weight ◽  
Aluminum Foams ◽  
Forming Process ◽  
Molding Process ◽  
Foaming Agent ◽  
Cylindrical Mold

A molding process of aluminum foams by using a rotating mold is proposed in order to improve the mold filling and forming process for light-weight parts of vehicles. Aluminum powder mixed with a foaming agent is extruded into the mold through the die heated to a temperature higher than the melting point, and the mold is filled with the aluminum foam. When the diameter of a cylindrical mold is large, the influence of gravity is significant and the mold is not filled successfully. In the proposed molding, the aluminum foam is extruded into the rotating mold of large diameter and the volumetric ratio of foam to mold cavity is improved. However, the effect of the mold rotation on the mold filling is limited due to friction.

High Strain Rate Behavior of Carbon Nanotubes Reinforced Aluminum Foams

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Abdelhakim Aldoshan ◽  
D. P. Mondal ◽  
Sanjeev Khanna
Keyword(s):  
Carbon Nanotubes ◽  
Strain Rate ◽  
Aluminum Foam ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Strain Rates ◽  
Aluminum Foams ◽  
Static Compression ◽  
Closed Cell

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.

Influence of Imperfections on Effective Properties of Cellular Solids

1998 ◽  
Vol 521 ◽  
Author(s):  
Joachim L. Grenestedt
Keyword(s):  
Cell Shape ◽  
Aluminum Foam ◽  
Effective Properties ◽  
Main Body ◽  
Cellular Solids ◽  
Aluminum Foams ◽  
Closed Cell ◽  
Perfect Model ◽  
Foam Properties ◽  
Solid Foams

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.

Impact Toughness of Closed-Cell Aluminum Foam

2018 ◽  
Vol 933 ◽  
pp. 203-208
Author(s):  
Yong Liang Mu ◽  
Ding Ding Wang ◽  
Yong Dong He ◽  
Guang Chun Yao
Keyword(s):  
Impact Toughness ◽  
Aluminum Foam ◽  
Impact Load ◽  
Peak Load ◽  
Load History ◽  
Notched Specimens ◽  
State Of Stress ◽  
Closed Cell ◽  
The Impact ◽  
Rupture Mode

The impact toughness of closed-cell aluminum foam with various densities was investigated. The impact load history revealed an elastic region followed by a rapid load drop region. The peak load and impact toughness of aluminum foam increases exponentially with density. The power exponents for impact toughness test are greater than that for compressive test. Fracture analysis indicated a mixed-rupture mode of quasi-cleavage and small shallow dimples. It can be attributed to the complex state of stress of notched specimens and elevated impact velocity under impact loading.

Quasi-Static Compressive Characteristics of Cu-Containing Closed-Cell Aluminum Foams

2017 ◽  
Vol 748 ◽  
pp. 173-180
Author(s):  
Jing Wang ◽  
Zan Zhang ◽  
Jian Ding ◽  
Chuan Rong Qiu ◽  
Xing Chuan Xia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Aluminum Foam ◽  
Pure Aluminum ◽  
Aging Treatment ◽  
Compressive Properties ◽  
Aluminum Foams ◽  
Commercially Pure ◽  
Closed Cell ◽  
Heat Treated

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.

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