Experimental study of ballistic resistance of sandwich targets with aluminum face-sheet and graded foam core

2018 ◽  
Vol 22 (2) ◽  
pp. 461-479 ◽  
Author(s):  
A Alavi Nia ◽  
M Kazemi
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Single Layer ◽  
Average Density ◽  
Face Sheet ◽  
Foam Core ◽  
Ballistic Limit ◽  
Ballistic Resistance ◽  
Damaged Zone ◽  
The Impact

In this research, we have investigated the ballistic resistance of sandwich structures with aluminum face-sheet and graded polyurethane foam core with different densities. The effects of graded changes of core foam density and the effect of the sequence of foam layers with different densities on energy absorption and ballistic limit of sandwich structures under the impact of hemispherical nose projectiles at high speeds (160 to 300 m/s) are studied. The results of this study showed that increasing the density and thickness of the foam core leads to increase in the ballistic limit and energy absorption; also, the ballistic limit of sandwich structures with the same mass with graded foam core for three- and five-layer panels is, respectively, 10.37 and 5.57% more than single-layer foam core with the average density in case the foam layer with less density is placed in the impact side. By using the graded foam core (laminate), the core resistance is increased and the damaged zone shape is changed, and the energy absorption of back face-sheet is increased.

Ballistic resistance and energy absorption of honeycomb structures filled with reactive powder concrete prisms

2017 ◽  
Vol 19 (5) ◽  
pp. 544-571 ◽  
Author(s):  
Xiaochao Jin ◽  
Tao Jin ◽  
Buyun Su ◽  
Zhihua Wang ◽  
Jianguo Ning ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Design Parameters ◽  
Reactive Powder Concrete ◽  
Velocity Range ◽  
Hexagonal Cell ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Reactive Powder ◽  
The Impact

Two kinds of innovative re-entrant and hexagonal cell honeycomb sandwich structures filled with reactive powder concrete were proposed, and the ballistic resistance and energy absorption of the sandwich structures were investigated by numerical simulations. The deformation and failure modes of the different structures were analyzed and evaluated in detail. The honeycomb sandwich structures filled with reactive powder concrete prisms improved the capacity of ballistic resistance and energy absorption significantly, compared to the normal reactive powder concrete plates and sandwich structures without reactive powder concrete prisms. The analysis shows that the auxetic re-entrant cell honeycomb sandwich structures have a better ballistic performance than the hexagonal cell honeycomb sandwich structures. The sandwich structures were subjected to impact by three kinds of projectiles: flat, hemispherical and conical nosed. The ballistic limit of the flat nosed projectile is the highest, while the impact performance of the conical and hemispherical nosed projectiles is obviously different from the flat nosed projectile, especially in a relative high velocity range. The sharper nose leads to a higher value of exit velocity and mass loss. In addition, effects of different design parameters on ballistic resistance were also studied by changing the thickness of honeycomb cell and face plates. Results indicate that the thickness of honeycomb walls and face plates have significant effect on the ballistic resistance and energy absorption in a relative low velocity range, while there are no big differences when the initial impact velocity exceeds 400 m/s.

Ballistic impact behaviors of aluminum alloy sandwich panels with honeycomb cores: An experimental study

2016 ◽  
Vol 20 (7) ◽  
pp. 861-884 ◽  
Author(s):  
QN Zhang ◽  
XW Zhang ◽  
GX Lu ◽  
D Ruan
Keyword(s):  
Aluminum Alloy ◽  
Energy Absorption ◽  
Impact Velocity ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Ballistic Limit ◽  
Core Density ◽  
Impact Tests ◽  
Honeycomb Cores

To study the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted, in which the thicknesses of the face sheet and core were 0.5–2.0 and 12.7 mm, respectively, while projectiles with diameter 7.5 mm and impact velocity 50–220 m/s were employed. Based on the experiments, the influences of impact velocity, face sheet thickness, core density as well as the nose shape of the projectiles were investigated. The results showed that in the impact tests, the sandwich panels dissipated much more energy than those in quasi-static perforation tests, and the energy absorption and ballistic limit of the sandwich panels increased with the increase of impact velocity. The influence of face sheet thickness was more remarkable than the core density, which was due to the relative density of honeycomb is too small. Although the increase of core density could induce the increase of energy absorption, this effect is more effective for thinner face sheet. Moreover, under the same impact velocity about 200 m/s and face sheet thickness 1.0 mm, the ballistic limit for conical-nosed projectile is highest, while it is lowest for flat-nosed projectile.

Study on Ballistic Energy Absorption of Laminated and Sandwich Composites

2006 ◽  
Vol 306-308 ◽  
pp. 739-744 ◽  
Author(s):  
Xiao Dong Cui ◽  
Tao Zeng ◽  
Dai Ning Fang
Keyword(s):  
Energy Absorption ◽  
Impact Response ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Composite ◽  
Improved Model ◽  
Energy Absorbing ◽  
The Impact

The impact response and energy absorbing characteristics of laminated, foam sandwich and honeycomb sandwich composites under ballistic impact have been studied in this investigation. An improved model is proposed in this paper to predict the ballistic property of the laminated composites. In this model, the material structures related to fiber lamination angles are designed in terms of their anti-impacting energy absorption capability. The ballistic limit speed and energy absorption per unit thickness of the three composites under different conditions are calculated. It is shown that honeycomb sandwich composite has the best ballistic resistance capability and energy absorption property among the three composites.

Study on Ballistic Characteristics of Glass-Epoxy-Rubber Sandwiches

2020 ◽  
Vol 978 ◽  
pp. 245-249
Author(s):  
Rajole Sangamesh ◽  
Hiremath Shivashankar ◽  
K.S. Ravishankar ◽  
S.M. Kulkarni
Keyword(s):  
Natural Rubber ◽  
Energy Absorption ◽  
Experimental Validation ◽  
Absorption Capacity ◽  
Velocity Variation ◽  
Ballistic Limit ◽  
Ballistic Performance ◽  
Energy Absorption Capacity ◽  
Ballistic Limit Velocity ◽  
The Impact

This article focuses on the Finite Element (FE) analysis of the ballistic performance of the polymer composites consisting of natural rubber (NR), glass-epoxy (GE) and glass-rubber-epoxy (GRE) sandwich of different thicknesses (3, 6 and 9 mm) under the impact of the conical nose projectile for a velocity variation of (180, 220 and 260 m / s). FE modeling was carried out in direction to forecast the energy absorption, ballistic limit velocity and failure damage mode of the target materail. The significant influence of thickness, interlayer and sandwiching effect was studied: the lowest ballistic limit was obtained for 3 mm thick GE. Energy absorption capacity of GRE sandwich was highest among the natural rubber and GE. In future, the work can be extended for the experimental validation purpose, so that these polymer composite materials could be utilized to defence sector for bullet-proofing.

Numerical Simulation of Low Velocity Impact on Pin-Reinforced Foam Core Sandwich Panel

2017 ◽  
Vol 742 ◽  
pp. 673-680
Author(s):  
M. Adli Dimassi ◽  
Axel S. Herrmann
Keyword(s):  
Sandwich Structures ◽  
Element Model ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Industrial Sectors ◽  
Out Of Plane ◽  
Scale Modelling ◽  
Cohesive Zone Elements ◽  
The Impact

The use of sandwich structures is well established in industrial sectors where high stiffness and strength combined with lightweight are required, like in marine, wind turbine and railway applications. However, the vulnerability of sandwich structures to low-velocity impacts limits its use in primary aircraft structures. Pin reinforcement of the foam core enhances the out-of-plane properties and the damage tolerance of the foam core. In this paper, a finite element model is proposed to predict the impact behaviour of pin-reinforced sandwich structure. An approach based on the building block approach was used to develop the model. Multi-scale modelling in the impact region that considers the delamination of the face sheet using cohesive zone elements was employed to increase the accuracy of the simulation. Impact tests were performed to validate the numerical model. A good agreement between numerical and experimental results in terms of contact-force displacement history and failure mode was found.

Numerical Modeling of Energy Absorption Behaviour of Aluminium Foam Cored Sandwich Panels with Different Fibre Reinforced Polymer (FRP) Composite Facesheet Skins

2016 ◽  
Vol 852 ◽  
pp. 66-71 ◽  
Author(s):  
M. Nalla Mohamed ◽  
D. Ananthapadmanaban ◽  
M. Selvaraj
Keyword(s):  
Energy Absorption ◽  
High Velocity ◽  
Sandwich Panels ◽  
Aluminium Foam ◽  
Foam Core ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
The Impact

Sandwich structures based on Fibre Reinforced Polymer (FRP) facesheet skins bonded with low density aluminium foam core are increasing in use in aerospace and marine industries. These structures are very sensitive to high velocity impact during the service. Therefore, it is necessary to study the energy absorption of the structures to ensure the reliability and safety in use. Experimental investigation of these transient events is expensive and time-consuming, and nowadays the use of numerical approaches is on the increase. Hence, the purpose of this paper is to develop a numerical model of sandwich panels with aluminium foam as a core and Glass, Carbon and Kevlar Fibre Reinforced polymer composite as faceplate, subjected to high velocity impact using ABAQUS/Explicit. The influence of individual elements of the sandwich panel on the energy absorption of the structures subjected to high velocity impact loading was analysed. Selection of suitable constitutive models and erosion criterion for the damage were discussed. The numerical models were validated with experimental data obtained from the scientific literature. Good agreement was obtained between the simulations and the experimental results. The contribution of the face sheet, foam core on the impact behaviour was evaluated by the analysis of the residual velocity, ballistic limit, and damaged area.

Light Weight Sandwich Panels for Yacht Hull Structures

2005 ◽  
Author(s):  
M. C. Rice ◽  
C. A. Fleischer ◽  
D. D. R. Cartie ◽  
Marc Zupan
Keyword(s):  
Carbon Fiber ◽  
Sandwich Structures ◽  
Material Selection ◽  
Sandwich Panels ◽  
Material Behavior ◽  
Face Sheet ◽  
Foam Core ◽  
Light Weight ◽  
Polymer Foam ◽  
Out Of Plane

Improving lightweight structures is a continuous challenge for yacht hull structural components. Sandwich beams consisting of strong face sheets and a low density core have gained application as weight efficient structures subjected to bending loads. The sandwich structure provides good stiffness by keeping the face sheets at a fixed distance with considerable weight reduction over a statically equivalent monolithic panel. New fabrication technologies now allow for hybrid sandwich structures, known as X-cor to be manufactured. X-cor panels consist of carbon fiber face sheets separated by a closed cell polymer foam core reinforced with carbon fiber or metallic (Titanium or Steel) pins. The pins are inserted into the light weight foam core in the out-of-plane direction and extend from face sheet to face sheet. Pin orientation and concentration can be varied providing a large design space for scientist and designer to explore and to improve material performance. The effect of core thickness, pin reinforcing and polymer foam core on the out-of-plane axial compression response of these panel will be presented. The through thickness three- point simply supported bending behavior of these reinforced panels is used to evaluate the core shear, stretch, face sheet failure characteristics of the structures. Explicit experimental observations are used to develop and calibrate analytical energy balance models to generate failure mode maps describing the panel collapse load as a function of geometry. Multi-scale effective modeling, blurring the distinction between structural and material behavior, will enable optimization of the X-cor sandwich structures in light of Yacht hull design requirements. The mechanical response of X-cor sandwich panels will be compared to current Yacht hull materials using material selection charts, and demonstrator components presented.

scholarly journals Impact Performance and Bending Behavior of Carbon-Fiber Foam-Core Sandwich Composite Structures in Cold Arctic Temperature

2020 ◽  
Vol 4 (3) ◽  
pp. 133
Author(s):  
M.H. Khan ◽  
Bing Li ◽  
K.T. Tan
Keyword(s):  
Carbon Fiber ◽  
Impact Damage ◽  
Matrix Cracking ◽  
Face Sheet ◽  
Foam Core ◽  
Impact Performance ◽  
Post Impact ◽  
Bending Behavior ◽  
Impact Bending ◽  
The Impact

This study investigates the impact performance, post-impact bending behavior and damage mechanisms of Divinycell H-100 foam core with woven carbon fiber reinforced polymer (CFRP) face sheets sandwich panel in cold temperature Arctic conditions. Low-velocity impact tests were performed at 23, −30 and −70 °C. Results indicate that exposure to low temperature reduces impact damage tolerance significantly. X-ray microcomputed tomography is utilized to reveal damage modes such as matrix cracking, delamination and fiber breakage on the CFRP face sheet, as well as core crushing, core shearing and debonding in the Polyvinyl Chloride (PVC) foam core. Post-impact bending tests reveal that residual flexural properties are more sensitive to the in-plane compressive property of the CFRP face sheet than the tensile property. Specifically, the degradation of flexural strength strongly depends on pre-existing impact damage and temperature conditions. Statistical analyses based on this study are employed to show that flexural performance is dominantly governed by face sheet thickness and pre-bending impact energy.

Evaluation of the effect of core lattice topology on the properties of sandwich panels produced by additive manufacturing

2020 ◽  
pp. 146442072095801
Author(s):  
JG Monteiro ◽  
M Sardinha ◽  
F Alves ◽  
AR Ribeiro ◽  
L Reis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Relative Density ◽  
Energy Absorption ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Single Layer ◽  
Thin Plates ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Manufacturing Technologies

Sandwich structures are frequently used in automotive, aerospace and marine industries, as they provide adequate functional properties. The two-dimensional regular hexagonal cell shape, i.e. honeycomb is the most used core structure in sandwich panels. Recently, a new type of cellular structures composed of lattice struts has been proposed, as they combine high stiffness, strength and energy absorption with low weight. The main purpose of this research is to investigate the effect of the lattice topology on the flexural behaviour of sandwich panels. Five lattice geometries inspired in crystalline structures were designed, namely, body-centred parallelepiped, body-centred parallelepiped with struts in z-axis, body- and face-centred parallelepiped with struts in z-axis, face-centred parallelepiped with struts in z-axis and parallelepiped simple. The relative density of all the lattices was kept constant as 0.3. Both numerical and experimental approaches were used to evaluate the flexural properties and failure behaviour of the sandwich structures under three-point bending tests. The numerical analysis was undertaken with the finite element software NX Nastran. Taking advantage of additive manufacturing technologies, material extrusion was used to produce polylactic acid samples with the configurations aforementioned. The sandwich panels are composed by a single layer formed by the lattice core and two thin plates, at the bottom and top. The three parts of the panel were manufactured all together. The simulation results indicate that, among the lattices studied, topologies body-centred parallelepiped with struts in z-axis and body- and face-centred parallelepiped with struts in z-axis exhibit higher strength, while body- and face-centred parallelepiped with struts in z-axis shows higher stiffness and higher energy absorption, attaining values that do not differ much from the ones obtained with a two-dimensional hexagonal cellular structure, with the same relative density. As a consequence, some of the geometries studied may have the potential to be considered as alternatives to conventional structures in the design of sandwich structures.

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