scholarly journals An analytical model of linear density foam–protected structure under blast loading

2017 ◽  
Vol 8 (3) ◽  
pp. 454-472 ◽  
Author(s):  
Ye Xia ◽  
Chengqing Wu ◽  
Terry Bennett
Keyword(s):  
Energy Absorption ◽  
Analytical Model ◽  
Linear Density ◽  
Blast Resistance ◽  
Blast Loading ◽  
Maximum Energy ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
Structural Deformation ◽  
Reinforced Concrete Structure

Aluminium foam is widely known as an energy absorptive material which can be used as a protective cladding on structures to enhance blast resistance of the protected structures. Previous studies show that higher density provides larger energy absorption capacity of aluminium foam, but results in a larger transmitted pressure to the protected structure. To lower the transmitted pressure without sacrificing the maximum energy absorption, graded density foam has been examined in this study. An analytical model is developed in this article to investigate the protective effect of linear density foam on response of a structure under blast loading. The model is able to simulate structural deformation with reasonable accuracy compared with experimental data. The sensitivity of density gradient of foam cladding on reinforced concrete structure is tested in the article.

scholarly journals Theoretical Analysis of Blast Protection of Graded Metal Foam-Cored Sandwich Cylinders/Rings

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3903 ◽  
Author(s):  
Minzu Liang ◽  
Xiangyu Li ◽  
Yuliang Lin ◽  
Kefan Zhang ◽  
Fangyun Lu
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Metal Foam ◽  
Blast Resistance ◽  
Structural Response ◽  
Blast Loading ◽  
Absorption Capacity ◽  
Analytical Models ◽  
Face Sheet ◽  
Energy Absorption Capacity

The blast resistance of a sandwich-walled cylinder/ring comprising two metal face-sheets and a graded metal foam core, subjected to internal air blast loading, is investigated. Analytical models are developed for the deformation of the sandwich cylinder with positive and negative gradient cores under internal blast loading. The deformation process is divided into three distinct phases, namely the fluid–structure interaction phase, core-crushing phase, and outer face-sheet deformation phase. Finite element modeling is performed using the Voronoi material model. The proposed analytical models are verified through finite element analysis, and reasonable agreement is observed between the analytical predictions and finite element results. The sandwich structures with high energy absorption capacity or low maximum radial deflection are satisfied for the protecting purpose of impact/blast resistance requirements. Typical deformation processes are classified and analyzed; the effects of explosive charge, face-sheet thickness, and core gradient on the structural response are also examined. The results indicate that both the deformation modes and the structural response of the cylinders are sensitive to the blast charge and core configuration. It is concluded that energy absorption capacity and maximum radial deflection are two conflicting goals for achieving high impact/blast resistance capability. An in-depth understanding of the behavior in sandwich-walled cylinders under blast impulse and the influence of the core configuration helps realize the advantages and disadvantages of using graded foam materials in sandwich structures and can provide a guideline for structural design.

scholarly journals Dynamic Compressive Behaviors of Two-Layer Graded Aluminum Foams under Blast Loading

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1445 ◽  
Author(s):  
Minzu Liang ◽  
Xiangyu Li ◽  
Yuliang Lin ◽  
Kefan Zhang ◽  
Fangyun Lu
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Blast Resistance ◽  
Blast Loading ◽  
Deformation Energy ◽  
Aluminum Foams ◽  
Conflicting Objectives ◽  
Energy Dissipated ◽  
Transmitted Impulse ◽  
Energy Absorbing

Experimental and numerical analyses were carried out to reveal the behaviors of two-layer graded aluminum foam materials for their dynamic compaction under blast loading. Blast experiments were conducted to investigate the deformation and densification wave formation of two-layer graded foams with positive and negative gradients. The shape of the stress waveform changed during the propagation process, and the time of edge rising was extended. Finite element models of two-layer graded aluminum foam were developed using the periodic Voronoi technique. Numerical analysis was performed to simulate deformation, energy absorption, and transmitted impulse of the two-layer graded aluminum foams by the software ABAQUS/Explicit. The deformation patterns were presented to provide insights into the influences of the foam gradient on compaction wave mechanisms. Results showed that the densification wave occurred at the blast end and then gradually propagated to the distal end for the positive gradient; however, compaction waves simultaneously formed in both layers and propagated to the distal end in the same direction for the negative gradient. The energy absorption and impulse transfer were examined to capture the effect of the blast pressure and the material gradient. The greater the foam gradient, the more energy dissipated and the more impulse transmitted. The absorbed energy and transferred impulse are conflicting objectives for the blast resistance capability of aluminum foam materials with different gradient distributions. The results could help in understanding the performance and mechanisms of two-layer graded aluminum foam materials under blast loading and provide a guideline for effective design of energy-absorbing materials and structures.

Methods for Filling Hollow Structures with Aluminium Foam

2010 ◽  
Vol 638-642 ◽  
pp. 61-66 ◽  
Author(s):  
Joachim Baumeister
Keyword(s):  
Energy Absorption ◽  
Hybrid Structure ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
Compression Tests ◽  
Foaming Agent ◽  
Hollow Structures ◽  
Industrial Sectors ◽  
Foam Filling ◽  
Application Potential

Aluminium foams produced according to the powder metallurgical/foaming agent process are currently being used in several industrial sectors, such as automotive, rail transport or machine tools. Nevertheless there still is a high further application potential to be exploited. Especially in hybrid structures, e.g. in automotive structures that are locally filled with aluminium foam, great improvements regarding the energy absorption capacity and the sound absorption behaviour can be obtained. In the present paper several methods that allow for filling or local filling of hollow structures are investigated and presented. The effect of the foam filling on the energy absorption behaviour of the hybrid structure is discussed. Similar effects were also observed in compression tests on foam filled hollow profiles. The results of these investigations are presented.

scholarly journals Dynamic Response and Optimal Design of Curved Metallic Sandwich Panels under Blast Loading

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Chang Qi ◽  
Shu Yang ◽  
Li-Jun Yang ◽  
Shou-Hong Han ◽  
Zhen-Hua Lu
Keyword(s):  
Dynamic Response ◽  
Energy Absorption ◽  
Sandwich Panel ◽  
Blast Resistance ◽  
Blast Loading ◽  
Outer Face ◽  
Air Blast ◽  
Blast Response ◽  
Artificial Neural Network Ann ◽  
Air Blast Loading

It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a “soft” outer face and a “hard” inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances.

Effect of core corrugation angle on static compression of self-reinforced PP sandwich panels and bending energy absorption of sandwich beams

2020 ◽  
pp. 002199832096053
Author(s):  
Ali Imran ◽  
Shijie Qi ◽  
Pengcheng Shi ◽  
Muhammad Imran ◽  
Dong Liu ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Structural Parameters ◽  
Maximum Energy ◽  
Absorption Capacity ◽  
Ex Situ ◽  
Static Compression ◽  
Reinforced Polymer ◽  
Optimization Study ◽  
Out Of Plane ◽  
Optimal Stiffness

The structural weight of an electric vehicle and its material’s recyclability are the important parameters to optimize the overall cost as well as the mileage of a vehicle. Self-reinforced polymer composites (SRCs) can be potentially used for these applications because of their 100% recyclability as compared with multicomponent traditional epoxy matrix based fibre reinforced composites. In case of SRCs the fibres and matrix are synthesized from same family of polymers. An optimization study is required based on integration of material and structural parameters to reduced overall weight of the vehicles while keeping the strength up to the safety mark. We fabricated self-reinforced polypropylene (SrPP) sandwich structures through an ex-situ consolidation based fabrication method. An FEA based study was conducted to optimize the effect of core corrugation angle of sandwiched structures on out of plane compressive strength and flexural strength of SrPP sandwiched beams. The finite element study was preferred in order to save the experimental cost. Beams with 60° core corrugation angle have optimal flexural properties. The sandwiched panels with 45° corrugated core exhibited optimal stiffness while maximum energy absorption capacity was shown with 60° corrugated core sandwiched structures.

The Dynamic Response of Sandwich Structures with Cellular Metallic Core under Blast Loading

2018 ◽  
Vol 933 ◽  
pp. 188-195 ◽  
Author(s):  
Yu Chen Guo ◽  
Gui Ping Zhao
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Blast Resistance ◽  
Hollow Spheres ◽  
Blast Loading ◽  
Dynamic Responses ◽  
Face Sheet ◽  
Outer Face ◽  
Aluminum Foams ◽  
Finite Element Software

The dynamic responses of sandwich structures with MHS(metal hollow sphere)and closed cell aluminum foams under blast loading were simulated numerically by employing the finite element software ANSYS/LS-DYNA. Both sandwich panels and sandwich spheres were modeled. Some factors that determine the blast resistance of the sandwich structures were investigated. According to the parametric studies, the sandwich structures with thin inner face sheet and thick outer face sheet have stronger blast resistance than others. Also the results show that sandwich structures with interlaced hollow spheres have a better performance than those with paratactic hollow spheres. Moreover, it's inferred that the density graded core with the biggest density as the first impact layer and the least density as the last layer has more benefits in energy absorption. The comparison between sandwich structures with metal hollow spheres and those with aluminum foams was studied experimentally and numerically and the results demonstrate that structures with aluminum foam have advantage in energy absorption but structures with MHS are stronger and can undertake more TNT.

scholarly journals Compressive Crush Performance of Square Tubes Filled with Spheres of Closed-Cell Aluminum Foams

2017 ◽  
Vol 62 (3) ◽  
pp. 1755-1760 ◽  
Author(s):  
A. Uzun
Keyword(s):  
Energy Absorption ◽  
Spherical Shape ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
The Other ◽  
Aluminum Foams ◽  
Energy Absorption Capacity ◽  
Closed Cell ◽  
Different Diameters ◽  
Powder Metallurgy Methods

AbstractThis paper describes the compressive crush behaviour of spheres of closed-cell aluminium foams with different diameters (6, 8 and 10 mm) and square tubes filled with these spheres. The spheres of closed-cell aluminium foams are net spherical shape fabricated via powder metallurgy methods by heating foamable precursor materials in a mould. The square tubes were filled by pouring the spheres of closed-cell aluminium foams freely (without any bonding). The compressive crush performance of square tubes filled with spheres of closed-cell aluminum foams were compared to that of the empty tubes. The results show a significant influence of the spheres of closed-cell aluminium foam on the average crushing load of the square tubes. The energy absorption in the square tube filled with spheres of closed-cell aluminium foam with diameters of 10 mm is higher than in the other square tubes. The spheres of closed-cell aluminium foams led to improvement of the energy absorption capacity of empty tubes.

Structural Response and Energy Absorption of Sandwich Panels with an Aluminium Foam Core under Blast Loading

2008 ◽  
Vol 11 (5) ◽  
pp. 525-536 ◽  
Author(s):  
Feng Zhu ◽  
Longmao Zhao ◽  
Guoxing Lu ◽  
Zhihua Wang
Keyword(s):  
Energy Absorption ◽  
Sandwich Panels ◽  
Structural Response ◽  
Blast Loading ◽  
Aluminium Foam ◽  
Foam Core ◽  
Failure Patterns ◽  
Loading Process ◽  
Simulation And Experiment ◽  
Absorption Performance

This paper first presents an experimental investigation into the response of square sandwich panels with an aluminium foam core under blast loading, followed by a corresponding FE simulation using LS-DYNA. In the simulation, the loading process of explosive and response of the sandwich panels have been investigated. The blast loading process includes both the explosion procedure of the charge and interaction with the panel. The simulation result shows that the deformation/failure patterns observed in the tests are well captured by the numerical model, and quantitatively a reasonable agreement has been obtained between the simulation and experiment. Finally, a parametric study has been carried out to investigate the energy absorption performance of sandwich panels.

NUMERICAL STUDY OF BLAST-RESISTANT SANDWICH PANELS WITH ROTATIONAL FRICTION DAMPERS

2013 ◽  
Vol 13 (06) ◽  
pp. 1350014 ◽  
Author(s):  
WENSU CHEN ◽  
HONG HAO
Keyword(s):  
Energy Absorption ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Blast Resistance ◽  
Sandwich Panels ◽  
Blast Loading ◽  
Blast Loads ◽  
Friction Damper ◽  
Energy Absorber ◽  
Blast Energy

Blast-resistant structures are traditionally designed with solid materials of huge weight to resist blast loads. This not only increases the construction costs, but also undermines the operational performance. To overcome these problems, many researchers develop new designs with either new materials or new structural forms, or both to resist the blast loads. Friction damper, as a passive energy absorber, has been used in earthquake-resistant design to absorb vibration energy from cyclic loading. The use of friction damper in blast-resistant design to absorb high-rate impact and blast energy, however, has not been well explored. This study introduces a new sandwich panel equipped with rotational friction hinge device with spring (RFHDS) between the outer and inner plates to resist the blast loading. This device RFHDS, as a special sandwich core and energy absorber, consists of rotational friction hinge device (RFHD) and spring. The RFHD is used to absorb blast energy while the spring is used to restore the original shape of the panel. This paper studies the mechanism of RFHD by using theoretical derivation and numerical simulations to derive its equivalent force–displacement relation and study its energy absorption capacity. In addition, the energy absorption and blast loading resistance capacities of the sandwich panel equipped with RFHDS are numerically investigated by using Ls-Dyna. It is found that the proposed sandwich panel can recover, at least partially its original configuration after the loading and thus maintain its operational and blast-resistance capability after a blasting event. In order to maximize the performance of the proposed sandwich panel, parametric calculations are carried out to study the performance of RFHDS and the sandwich panels with RFHDS. The best performing sandwich panel with RFHDS in resisting blast loadings is identified. This sandwich panel configuration might be employed to mitigate blast loading effects in structural sandwich panel design.

Numerical Simulation on Bending Characteristics of Aluminium Foam Filled Thin-Walled Tubes

2011 ◽  
Vol 213 ◽  
pp. 88-92 ◽  
Author(s):  
Qing Chun Wang ◽  
Hao Long Niu ◽  
Guo Quan Wang ◽  
Yu Xin Wang
Keyword(s):  
Energy Absorption ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
Bending Energy ◽  
Energy Absorption Capacity ◽  
Thin Walled Structures ◽  
Foam Filling ◽  
Foam Filled ◽  
Thin Walled ◽  
Energy Absorbing

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.

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