Meso-Complexity Computer Simulation Investigation on Antiexplosion Performance of Double-Layer Foam Aluminum under Pore Grading

Foam aluminum is an energy-absorbing material with excellent performance. The interlayer composed of multiple layers of foam aluminum and steel plate has good antiexplosion ability. In order to explore the antiexplosion performance of double-layer foam aluminum under different porosity rankings and to reveal its microscopic deformation law and failure mechanism, three kinds of aluminum foams with a porosity of 80%, 85%, and 90% were selected to form six different structures. Based on the Voronoi algorithm, a three-dimensional foam aluminum generation algorithm with random pore size and random wall thickness was written by using the Python language and Fortran language. The three-dimensional mesoscopic model of double-layer closed-cell aluminum foam sandwich panel is established by using LS-DYNA and ABAQUS software. The explosion process was simulated, and the flow field movement of explosion shock wave of aluminum foam under different porosity rankings was analyzed. Two groups of aluminum foam were randomly selected for the explosion test and compared for the strain and compression. The test results are consistent with the simulation results, which verifies the correctness of the three-dimensional meso-model. The results show that when the porosity of the upper layer of aluminum foam is greater than that of the lower layer of aluminum foam, the sandwich structure of double-layer aluminum foam has a large compression and the bottom plate has a small displacement; it is not that the greater the compression amount of aluminum foam is, the better the antiexplosion and wave absorption ability is. When the aluminum foam reaches the ultimate load-bearing capacity, the aluminum foam transfers the load due to compaction, resulting in stress enhancement phenomena. Through the analysis of the compression amount, floor deformation, wave dissipation capacity, and energy ratio of aluminum foam, it is concluded that the antiexplosion wave absorption effect of the sandwich structure of aluminum foam with 80%/85% group is the best; the changes of porosity and cell wall are important factors affecting the energy absorption capacity of aluminum foam.

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The Numerical Investigation of Aluminum Foam-protected Reinforced Concrete Slabs under Blast Loading Using AUTODYN-3D

MATEC Web of Conferences ◽

10.1051/matecconf/201820601014 ◽

2018 ◽

Vol 206 ◽

pp. 01014

Author(s):

Ahmed K. Taha ◽

Zhengguo Gao ◽

Dahai Huang

Keyword(s):

Reinforced Concrete ◽

Aluminum Foam ◽

Steel Plate ◽

Three Dimensional ◽

Experimental Tests ◽

High Energy ◽

Absorption Capacity ◽

Concrete Panels ◽

Reinforced Concrete Slabs ◽

Concrete Target

Aluminum foam is a lightweight material with high energy absorption capacity. In this study A Nonlinear three-dimensional hydrocode numerical simulation was carried out using autodyn-3d, which is an extensive code dealing with explosion problems. In this simulation, a high explosive material (comp B) is blasted against several concrete panels. The model was first validated using experimental tests carried out by Chengqing and has shown good results. Several numerical tests were carried out to study two parameters that affect the deflection of reinforced concrete panels. The parameters included are the thickness of concrete target and the thickness of steel plate. The results showed that increasing the thickness of the steel plate has an insignificant effect on the deflection of the reinforced concrete target while increasing the thickness of the concrete panel has a significant effect on the deflection of the concrete target.

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Oceanic warm cloud layers within multilevel cloud systems observed by satellite measurements

10.5194/egusphere-egu2020-6311 ◽

2020 ◽

Author(s):

Qi Liu ◽

Yuhao Ding ◽

Ping Lao

Keyword(s):

Double Layer ◽

Radiative Forcing ◽

Lower Layer ◽

Numerical Models ◽

Three Dimensional ◽

Single Layer ◽

Layer System ◽

Cloud Systems ◽

Warm Cloud ◽

Double Layer System

<p>Low-level warm clouds are a major component in multilayered cloud systems and are generally hidden from the top-down view of satellites with passive measurements. By using spaceborne radar data with fine vertical resolution, this study conducts an investigation on oceanic warm clouds embedded in multilayered structures. The occurrences of warm cloud overlapping and the geometric features of several kinds of warm cloud layers are examined. It is found that there are three main types of cloud systems that involve warm cloud layers, including warm single layer clouds, cold-warm double layer clouds and warm-warm double layer clouds. The two types of double layer clouds account for 23% and in the double layer occurrences warm-warm double layer subsets contribute about 13%. The global distribution patterns of these three types differ from each other. Single-layer warm clouds and the lower warm clouds in the cold-warm double layer system have nearly identical geometric parameters, while the upper and lower layer warm clouds in the warm-warm double layer system are distinct from the previous two forms of warm cloud layers. In contrast to the independence of the two cloud layers in cold-warm double layer system, the two kinds of warm cloud layers in the warm-warm double layer system may be coupled. The distance between the two layers in the warm-warm double layer system is weakly dependent on cloud thickness. Given the upper and lower cloud layer with moderate thickness around 1 km, the cloudless gap reaches its maximum exceeding 600 m. As the two cloud layers become even thinner or thicker, the cloudless gap decreases in thickness. It is believed that such knowledge on cloud overlapping is critical for fully understanding the distribution of warm clouds in three-dimensional space. The results derived in this study could help validating cloud results of numerical models, which are indeed three-dimensional in nature. They could also be used to improve the estimation of cloud radiative forcing, since it is affected by cloud occurrences and especially their vertical structures. It should be pointed out that solid explanations for the above cloud features cannot be presented by only using these satellite data themselves.&#160;</p>

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

Complexity ◽

10.1155/2020/9519832 ◽

2020 ◽

Vol 2020 ◽

pp. 1-2

Author(s):

Zhen Wang ◽

Wen Bin Gu ◽

Xing Bo Xie ◽

Qi Yuan ◽

Yu Tian Chen ◽

...

Keyword(s):

Sandwich Structure ◽

Aluminum Foam ◽

Three Dimensional ◽

Random Generation ◽

Generation Algorithm ◽

Mesoscopic Model ◽

Closed Cell

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Nanoferric tetroxide decorated N-doped residual carbon from entrained-flow coal gasification fine slag for enhancing the electromagnetic wave absorption capacity

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.159878 ◽

2021 ◽

Vol 874 ◽

pp. 159878

Author(s):

Jun He ◽

Shengtao Gao ◽

Yuanchun Zhang ◽

Hanxu Li

Keyword(s):

Electromagnetic Wave ◽

Coal Gasification ◽

Absorption Capacity ◽

Residual Carbon ◽

Electromagnetic Wave Absorption ◽

Wave Absorption ◽

Entrained Flow

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Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420721997490 ◽

2021 ◽

pp. 146442072199749

Author(s):

H Geramizadeh ◽

S Dariushi ◽

S Jedari Salami

Keyword(s):

Energy Absorption ◽

Sandwich Structures ◽

Three Dimensional ◽

Absorption Capacity ◽

The Novel ◽

Energy Absorption Capacity ◽

Fused Deposition ◽

Honeycomb Sandwich ◽

Out Of Plane ◽

Vertical Walls

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.

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Three-dimensional hierarchical structured Fe3O4/rGO/ZnO composite for effective electromagnetic wave absorption

Applied Physics A ◽

10.1007/s00339-021-04625-3 ◽

2021 ◽

Vol 127 (6) ◽

Author(s):

Juan Ding ◽

Ligang Cheng ◽

Xin Zhuang

Keyword(s):

Electromagnetic Wave ◽

Three Dimensional ◽

Electromagnetic Wave Absorption ◽

Wave Absorption

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Impact Resistance Analysis of a Composite Double-Layer Honeycomb Sandwich Structure

Strength of Materials ◽

10.1007/s11223-021-00268-0 ◽

2021 ◽

Author(s):

G. J. Bi ◽

J. P. Yin ◽

Z. J. Wang ◽

Y. Y. Han ◽

Z. J. Jia

Keyword(s):

Double Layer ◽

Sandwich Structure ◽

Impact Resistance ◽

Resistance Analysis ◽

Honeycomb Sandwich ◽

Honeycomb Sandwich Structure

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Complex Aerogels Generated from Nano-Polysaccharides and Its Derivatives for Oil–Water Separation

Polymers ◽

10.3390/polym11101593 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1593 ◽

Cited By ~ 4

Author(s):

Hajo Yagoub ◽

Liping Zhu ◽

Mahmoud H. M. A. Shibraen ◽

Ali A. Altam ◽

Dafaalla M. D. Babiker ◽

...

Keyword(s):

Guar Gum ◽

Corn Oil ◽

Cellulose Nanofibers ◽

Aqueous Media ◽

Three Dimensional ◽

Absorption Capacity ◽

Water Contact ◽

Water Separation ◽

Oil Water Separation ◽

Oil Water

The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil–water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155° on the aerogel surface and 150° on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

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