scholarly journals Cork Core Sandwich Plates for Blast Protection

2020 ◽  
Vol 10 (15) ◽  
pp. 5180
Author(s):  
Jesús Pernas-Sánchez ◽  
Jose A. Artero-Guerrero ◽  
David Varas ◽  
Filipe Teixeira-Dias
Keyword(s):  
Energy Absorption ◽  
Mechanical Response ◽  
Numerical Models ◽  
Areal Density ◽  
Absorption Capacity ◽  
Geometrical Parameters ◽  
Sandwich Plates ◽  
Arbitrary Lagrangian Eulerian ◽  
Reference Case ◽  
Blast Protection

A numerical model is developed and validated to analyse the performance of aluminium skin and agglomerated cork core sandwich plates subjected to blast loads. Two numerical approaches are used and thoroughly compared to generate the blast loading: an Arbitrary-Lagrangian–Eulerian approach and the Load Blast Enhanced method. Both of the models are validated by comparing the numerical results with experimental observations. A detailed analysis of the sandwich behaviour is done for both approaches showing small differences regarding the mechanical response of the sandwich structure. The results obtained from the numerical models uncover the specific energy absorption mechanisms happening within the sandwich plate components. A new core topology is proposed, based on these results, which maximises the energy absorption capacity of the plate, keeping the areal density unchanged. A wavy agglomerated cork core is proposed and the effects of different geometrical parameters on the energy absorption are thoroughly analysed and discussed. The proposed optimised plate configuration shows an increase in the total absorbed energy of close to 40% relative to a reference case with the same areal density. The adopted optimisation methodology can be applied to alternative configurations to increase the performance of sandwich structures under blast events.

scholarly journals Energy Absorption Capability of Thin-Walled Prismatic Aluminum Tubes with Spherical Indentations

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4304
Author(s):  
Miroslaw Ferdynus ◽  
Patryk Rozylo ◽  
Michal Rogala
Keyword(s):  
Aluminum Alloy ◽  
Energy Absorption ◽  
Numerical Models ◽  
Energy System ◽  
High Energy ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Numerical Tests ◽  
Thin Walled ◽  
Crushing Behavior

The paper presents the results of numerical tests of impact and energy absorption capacity of thin-walled columns, subjected to axial impact loading, made of aluminum alloy, and having a square cross-section and spherical indentations on their lateral surfaces. The numerical models were validated using an experiment that was conducted on the Instron CEAST 9350 High Energy System drop hammer. Material properties of the applied aluminum alloy were determined on the basis of a static tension test. The crushing behavior of the columns and some crashworthiness indicators were investigated. On the basis of the results of the conducted analyses, conclusions were drawn about the most beneficial design/constructional variants in terms of achieved crashworthiness parameters.

Quasi-Static Impact Response of Single-Curved Foldcore Sandwich Shells

2014 ◽  
Author(s):  
Joseph M. Gattas ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Mechanical Performance ◽  
Numerical Models ◽  
Preliminary Investigation ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Future Research ◽  
Initial Strength ◽  
Sandwich Shells ◽  
The Impact

Honeycomb core sandwich shells are used for many applications, but available unit architectures and global curvatures are limited. Numerous origami-core sandwich shells, known as foldcores, have been proposed as alternatives, but studies into their mechanical performance are few. This paper conducts a preliminary investigation into the impact resistance and energy absorption of single-curved foldcore sandwich shells that utilise Miura-derivative patterns as their core geometry. A numerical analysis on three Miura-derivative core patterns, the Arc-Miura (AM), Non-Developable Miura (ND), and Non-Flat Foldable Miura (NF) patterns, shows that ND and AM-type shells have similar impact resistance to each other, and superior impact resistance to NF-type shells. Prototypes of aluminium ND and AM-type foldcores are constructed and used to validate numerical models. Numerical models were then used to draw comparisons with an over-expanded honeycomb (OX-core) sandwich shell. It was seen that the OX-core had a better energy absorption capacity than either of the foldcores. However the AM-type foldcore possessed superior initial strength, and the ND-type possessed superior response uniformity, attributes that might be exploitable with future research. A brief parametric study on ND-type shells suggested that in general, for a given design radius and density, a foldcore shell configuration with a lower unit cell area-to-height ratio will have a higher energy absorption capability.

Quasi-Static Biaxial Plastic Buckling of Tubular Structures Used as an Energy Absorber

2006 ◽  
Vol 74 (4) ◽  
pp. 628-635 ◽  
Author(s):  
R. Baleh ◽  
A. Abdul-Latif
Keyword(s):  
Mild Steel ◽  
Energy Absorption ◽  
Strength Properties ◽  
Absorption Capacity ◽  
Loading Path ◽  
Geometrical Parameters ◽  
Tubular Structures ◽  
Plastic Buckling ◽  
Applied Loading ◽  
Plastic Strength

The aim of this experimental study is to improve the energy absorption capacity of tubular metallic structures during their plastic buckling by increasing the strength properties of materials. Based on a novel idea, a change in the plastic strength of materials could be predictable through the loading path complexity concept. An original experimental device, which represents a patent issue, is developed. From a uniaxial loading, a biaxial (combined compression–torsion) loading path is generated by means of this device. Tests are carried out to investigate the biaxial plastic buckling behavior of several tubular structures made from copper, aluminum, and mild steel. The effects of the loading path complexity, the geometrical parameters of the structures, and loading rates (notably the tangential one) on the plastic flow mechanism, the mean collapse load, and the energy absorbed are carefully analyzed. The results related to the copper and aluminum metals show that the plastic strength properties of the tubes crushed biaxially change with the torsional component rate. This emphasizes that the energy absorption improves with increasing the applied loading complexity. However, the energy absorbed data for the mild steel tubular structures do not demonstrate the same sensitivity to the quasi-static loading path complexity.

Influence of fabric architecture on crushing behavior of semi-hexagonal composite structures under axial loading

2018 ◽  
Vol 49 (2) ◽  
pp. 162-180 ◽  
Author(s):  
Zhenyu Wu ◽  
Maolin Wang ◽  
Zhiping Ying ◽  
Xiaoying Cheng ◽  
Xudong Hu
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Composite Structures ◽  
Failure Modes ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Numerical Models ◽  
Woven Fabric ◽  
Buckling Mode ◽  
Specific Energy Absorption

This paper reports the mechanical response of semi-hexagonal part with three different multi-layer reinforcements. Unidirectional, plain woven and orthogonal fabric under quasi-static axial compression were considered. Meso-scale finite element numerical models with failure criterion were also established to simulate the onset and development of internal damage during the compression process. There were two different crush-failure modes occurring in the crush tests of the three different composite samples: a splaying mode for samples with unidirectional fabric, a buckling mode for samples with 3D orthogonal woven fabric and a mixture mode of both buckling and splaying for samples with the plain woven fabric. The samples reinforced by unidirectional fiber have the highest specific energy absorption and lowest peak loading, whereas the samples by 3D orthogonal fabric present the lowest specific energy absorption and highest peak loading. It was also demonstrated by a numerical model that the existence of Z-binder suppresses the delamination by restraining the expanding of warp and weft yarns. The comparison of numerical results and experimental data indicates that the structure of reinforcement has a significant role in the mechanical performance of textile composite.

Energy Absorption of Thermoplastic Polyurethane Lattice Structures via 3D Printing: Modeling and Prediction

2016 ◽  
Vol 08 (07) ◽  
pp. 1640006 ◽  
Author(s):  
Fei Shen ◽  
Shangqin Yuan ◽  
Yanchunni Guo ◽  
Bo Zhao ◽  
Jiaming Bai ◽  
...  
Keyword(s):  
3D Printing ◽  
Energy Absorption ◽  
Mechanical Response ◽  
Thermoplastic Polyurethane ◽  
Selective Laser Sintering ◽  
Absorption Capacity ◽  
Lattice Structures ◽  
Energy Absorption Capacity ◽  
Cyclic Compression ◽  
Manufacturing Testing

This work investigates the energy absorption capacity of polymeric lattice structures through a systemic manufacturing, testing and modeling approaches. The lattice structures are designed to possess periodic cubic geometry with optimized spherical shells located at the cubic corners, and thermoplastic polyurethane (TPU) powders are used to fabricate such structures via selective laser sintering, a type of powder-based 3D printing technology. A hyperelastic model that considers the mullins effect and describes the cyclic compression stress–strain behavior of TPU is developed to simulate the mechanical response of its 3D-printed lattice structures under cyclic compression loading. After the validation of the model for printed structure, it is used to predict the energy absorption capacity of various designed structures.

Dynamic crashing behavior of thin-walled conical tubular structures with nonlinearly-graded diameters

2018 ◽  
Vol 233 (7) ◽  
pp. 2456-2466 ◽  
Author(s):  
Fengxiang Xu ◽  
Suo Zhang ◽  
Kunying Wu
Keyword(s):  
Energy Absorption ◽  
Absorption Capacity ◽  
Geometrical Parameters ◽  
Tubular Structures ◽  
Power Law Distribution ◽  
Thin Walled Structures ◽  
Conical Structure ◽  
Thin Walled ◽  
Energy Absorbing ◽  
Effective Design

Thin-walled structures with graded property have been paid more attention in recent years due to their significant balance between lightweight and crashworthiness. However, few studies have been focused on energy absorption capacity of thin-walled conical tubes with graded diameters. In this paper, the thin-walled conical aluminum tubes with nonlinearly-graded diameters are introduced and their corresponding crashing characteristics are performed. The diameters are assumed to nonlinearly vary according to a power-law distribution function primarily determined by a graded exponent n. It is found that the total weight of thin-walled conical tubes decreases with the increasing of the gradient exponent. The energy-absorbed performances such as specific energy absorption, initial peak crashing force, and mean crashing force of those graded tubular structures are numerically analyzed. And then the effects of various geometric parameters such as the gradient exponent, deformation distance, and diameter range on crashing behaviors are further evaluated. It is observed that those parameters especially the gradient exponent has significantly obvious effects on crashworthiness of the proposed nonlinearly graded tubes. It is also noted that the straight conical structure with gradient n = 1.0 may not show the best energy absorption characteristics compared with other gradients. The work could provide valuable information for effective design of thin-walled energy-absorbing structures with variable geometrical parameters.

scholarly journals Investigations on the Mechanical Response of Gradient Lattice Structures Manufactured via SLM

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 213 ◽  
Author(s):  
Judyta Sienkiewicz ◽  
Paweł Płatek ◽  
Fengchun Jiang ◽  
Xiaojing Sun ◽  
Alexis Rusinek
Keyword(s):  
Relative Density ◽  
Energy Absorption ◽  
Dynamic Loading ◽  
Mechanical Response ◽  
Lattice Structure ◽  
Dynamic Compression ◽  
Absorption Capacity ◽  
Lattice Structures ◽  
Compression Tests ◽  
Static And Dynamic Loading

The main aim of the paper is to evaluate the mechanical behavior or lattice specimens subjected to quasi-static and dynamic compression tests. Both regular and three different variants of SS 316L lattice structures with gradually changed topologies (discrete, increase and decrease) have been successfully designed and additively manufactured with the use of the selective laser melting technique. The fabricated structures were subjected to geometrical quality control, microstructure analysis, phase characterization and compression tests under quasi-static and dynamic loading conditions. The mismatch between dimensions in the designed and produced lattices was noticed. It generally results from the adopted technique of the manufacturing process. The microstructure and phase composition were in good agreement with typical ones after the additive manufacturing of stainless steel. Moreover, the relationship between the structure relative density and its energy absorption capacity has been defined. The value of the maximum deformation energy depends on the adopted gradient topology and reaches the highest value for a gradually decreased topology, which also indicates the highest relative density. However, the highest rate of densification was observed for a gradually increasing topology. In addition, the results show that the gradient topology of the lattice structure affects the global deformation under the loading. Both, static and dynamic loading resulted in both barrel- and waisted-shaped deformation for lattices with an increasing and a decreasing gradient, respectively. Lattice specimens with a gradually changed topology indicate specific mechanical properties, which make them attractive in terms of energy absorption applications.

scholarly journals Effect of Structural Parameters and Materials on the Mechanical Characteristics of Expansion Tube

2020 ◽  
Author(s):  
Zizhen Qi ◽  
Yuwu Zhang ◽  
and Yuliang Lin
Keyword(s):  
Tensile Stress ◽  
Energy Absorption ◽  
Mechanical Response ◽  
Structural Parameters ◽  
High Energy ◽  
Absorption Capacity ◽  
Parent Material ◽  
Expansion Tube ◽  
Tube Material ◽  
Energy Absorption Capacity

Expansion tube is ideal energy absorber which dissipates kinetic energy through plastic deformation and friction. There is an urgent need to understand the influence of key parameter, e.g. semi angle, tube material, and friction coefficient, on the mechanical response and energy absorption characteristics of expansion tube. In the present work, the material properties of the tubes were tested under quasi-static loading condition, and the numerical simulations were carried out by using commercial software ABAQUS. Based on the validated finite element simulation, all the semi angle, tube material, and friction have significant effects on the energy absorption capacity of expansion tube. The expansion tube with high tensile stress of parent material have high energy absorption capacity, while the specific energy absorption is linear with the tensile stress/density of tube material. This work would give a guidance to the structural design and parent materials selection for expansion tubes.

scholarly journals Computational modelling of particulate-reinforced materials up to high volume fractions: Linear elastic homogenisation

2017 ◽  
Vol 233 (6) ◽  
pp. 1101-1116
Author(s):  
Timothée Gentieu ◽  
Anita Catapano ◽  
Julien Jumel ◽  
James Broughton
Keyword(s):  
Representative Volume Element ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Numerical Models ◽  
Computational Modelling ◽  
Volume Element ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Representative Volume ◽  
Analytical Approaches

This work focuses on the analysis of the micro and macroscopic mechanical response of particle-reinforced composites. A particular attention is paid to the influence of two fundamental design parameters, i.e. the particles shape and their volume fraction (up to very high values ranging from 0 to almost 0.8), on the overall mechanical response of the structure as well as on the resulting elastic symmetry of the material. The strain energy-based homogenisation technique of periodic media is here applied to a 2D finite element model of a representative volume element of the composite. Different algorithms are developed to generate, with a good level of accuracy, the real microstructure of the composite material characterised by circular as well as polygonal particles. Moreover, for each studied configuration, a link between the geometrical parameters of the microstructure (particles shape, size, distribution, and volume fraction) and the size of the representative volume element is also provided in order to properly describe the constitutive behaviour of the composite at the macroscopic scale. The numerical results are compared with analytical models taken from the literature to prove on the one hand the limitations of the analytical approaches and on the other hand the effectiveness of the proposed numerical models.

Experimental and numerical study on static and dynamic axial crushing of square aluminum tubes: Effects of cutouts

2022 ◽  
pp. 204141962110654
Author(s):  
Tan-Trung Bui ◽  
Dhafar Al Galib ◽  
Abdelkrim Bennani ◽  
Ali Limam
Keyword(s):  
Energy Absorption ◽  
Numerical Study ◽  
Numerical Models ◽  
Peak Load ◽  
Absorption Capacity ◽  
Point Of View ◽  
Dynamic Tests ◽  
Axial Crushing ◽  
Circular Holes ◽  
Experimental Findings

The collapse of tubes under axial load is an important subject from the safety point of view, particularly in the design of energy absorbing devices used in many engineering applications. In this study, quasi-static and dynamic experiments were carried out on square thin-walled aluminum extrusions to investigate the effects of circular holes. Cutouts were introduced in the four corners of the square-section tube, not far from the end boundary of the tube, in order both to decrease the first peak load on the load-displacement characteristic and to control the collapse mode. Different aspects, such as the buckling modes and the energy absorption in quasi-static axial crushing tests, as well as dynamic effects and material rheology contributions in dynamic crushing tests, have been examined. For the dynamic tests, the parameters were the impacting mass and its velocity. The results showed a drop in the first peak function of the openings’ radius and the tube’s energy absorption capacity was kept. A comparison between static and dynamic tests results was carried out and the interpretation of the results in terms of deformation mechanism and energy absorption was discussed. Numerical simulations with the finite element code ABAQUS were conducted to confirm the experimental findings. The results of different numerical models, implicit and explicit calculations, that contribute to a basic understanding of the buckling and prediction of the crash behavior of the aluminum components without and with the cutouts are presented.

Sign in / Sign up

Export Citation Format

Share Document