Spherical indentation of closed-cell aluminum foams: An empirical force–depth relation

The energy absorption of different cell structures for closed-cell aluminum foam-filled Al tubes are investigated through quasi-static compression testing. Aluminum foams are fabricated under different pressures, obtaining aluminum foams with different cell sizes. It is found that the deformation of the foam core is close to the overall deformation, and the deformation band is seriously expanded when the cell size is fined, which leads to the increase of interaction. Results confirm that the foam-filled tubes absorb more energy due to the increase of interaction between the foam core and tube wall when the foaming pressure increases. The energy absorption efficiency of foam-filled tubes can reach a maximum value of 90% when the foam core is fabricated under 0.30 MPa, which demonstrates that aluminum foams fabricated under increased pressure give a new way for the applications of foam-filled tubes in the automotive industry.

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

Complexity ◽

10.1155/2020/8390798 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16 ◽

Cited By ~ 1

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.

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

Metals ◽

10.3390/met10070921 ◽

2020 ◽

Vol 10 (7) ◽

pp. 921 ◽

Cited By ~ 2

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.

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Shock Loading of Closed Cell Aluminum Foams in the Presence of an Air Cavity

Applied Sciences ◽

10.3390/app10124128 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4128

Author(s):

Mahesh Thorat ◽

Shiba Sahu ◽

Viren Menezes ◽

Amol Gokhale ◽

Hamid Hosano

Keyword(s):

Shock Waves ◽

Shock Tube ◽

Shock Loading ◽

Pressure Rise ◽

Incident Shock ◽

Foam Density ◽

Aluminum Foams ◽

Closed Cell ◽

Rigid Walls ◽

End Wall

It is important to protect assets located within cavities vulnerable to incident shock waves generated by explosions. The aim of the present work is to explore if closed cell aluminum foams can mediate and attenuate incident shocks experienced by cavities. A small cavity of 9 mm diameter and 2 mm length was created within the steel end-wall of a shock tube and exposed to shocks, directly or after isolating by aluminum foam liners. Shock waves with incident pressure of 9–10 bar travelling at a velocity of 1000–1050 m/s were generated in the shock tube. Compared to the no-foam condition, the pressure induced in the cavity was either equal or lower, depending on whether the foam density was low (0.28 g/cc) or high (0.31 to 0.49 g/cc), respectively. Moreover, the rate of pressure rise, which was very high without and with the low density foam barrier, reduced substantially with increasing foam density. Foams deformed plastically under shock loading, with the extent of deformation decreasing with increasing foam density. Some interesting responses such as perforation of cell walls in the front side and densification in the far side of the foam were observed by a combination of scanning electron microscopy and X-ray microscopy. The present work conclusively shows that shocks in cavities within rigid walls can be attenuated by using foam liners of sufficiently high densities, which resist densification and extrusion into the cavities. Even such relatively high-density foams would be much lighter than fully dense materials capable of protecting cavities from shocks.

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