scholarly journals Effect of Needle Type, Number of Layers on FPAFC Composite against Low-Velocity Projectile Impact

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 668
Author(s):  
Nandhu Prasad ◽  
Gunasekaran Murali ◽  
Sallal R. Abid ◽  
Nikolai Vatin ◽  
Roman Fediuk ◽  
...  
Keyword(s):  
Analytical Model ◽  
Composite Structures ◽  
Impact Resistance ◽  
Functionally Graded ◽  
Low Velocity ◽  
Projectile Impact ◽  
Damage Area ◽  
Needle Type ◽  
Number Of Layers ◽  
Protective Structures

Protective structures subjected to intensive loads that may benefit from the use of multilayer composite structures with excellent hardness and impact resistance represent an emerging research field in recent times. In this study, low-velocity projectile impact tests were performed on Functionally-graded Preplaced Aggregate Fibrous Concrete (FPAFC) mixtures to evaluate their performance. The effects of projectile needle type, fibre type and hybridization in addition to the number of layers in the composites on projectile impact were investigated. The bioinspiration of the excellent impact strength of turtle shells was used to design an FPAFC comprising a higher amount of steel and polypropylene fibres at the outer layers. In parallel, one and two-layered concretes were also cast to assess the effectiveness of three-layered FPAFC. The tests were performed on disc specimens using non-deformable compound bevel, convex edge and hollow edge projectiles. The damage severity was quantified by the top damage area, bottom damage area and depth of penetration. In addition, a simple analytical model for predicting the composite mass expulsion was developed and implemented. Findings indicated that regardless of fiber type and distribution, the compound bevel projectile needle produced the lowest impact numbers for all single, double and triple-layer specimens compared to the convex edge and hollow edge projectiles. Repeated projectile impacts increased the penetration depth and damaged area at the top and bottom surfaces of all targets. Targets were more resistant to convex edge and hollow edge projectile penetration than the compound bevel. The experimental and analytical model results for mass expelled from the top surface are reasonably acceptable. This research gives an idea of developing advanced fibrous composite with superior impact resistance for the promising protective structures.

scholarly journals Response of Novel Functionally-Graded Prepacked Aggregate Fibrous Concrete against Low Velocity Repeated Projectile Impacts

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 280
Author(s):  
Nandhu Prasad ◽  
Gunasekaran Murali ◽  
Roman Fediuk ◽  
Nikolai Vatin ◽  
Maria Karelina
Keyword(s):  
Impact Resistance ◽  
Single Layer ◽  
Functionally Graded ◽  
Low Velocity ◽  
Polypropylene Fibres ◽  
Projectile Impact ◽  
Reference Information ◽  
Fibrous Concrete ◽  
New Type ◽  
Research Gap

Preplaced Aggregate Fibrous Concrete (PAFC) is a newly minted composite that has recently become more popular. The production of PAFC involves two essential processes; first, the fibres and coarse aggregate were filled into the empty framework to form the first layer of a natural skeleton, followed by grout injecting. A cement grout fills the voids in the first layer skeleton with slight compaction. This process is repeated to complete the remaining layers; hence, a type of Functionally-graded Preplaced Aggregate Fibrous Concrete (FPAFC) is obtained. The most recent studies revealed that the literature regarding the high-velocity projectile impact on fibrous concrete is well documented; however, the low-velocity repeated projectile impact on PAFC is still unexplored and needs particular emphasis. This research aims to investigate the FPAFC made with a new type of steel and polypropylene fibres against low-velocity projectile impact to fill this research gap. In the current study, twelve mixes were prepared with mono and hybrid combinations of fibres for pioneering the possible utilization of fibres in FPAFC. The maximum fibre dosage in this study is limited to 2.4%. The projectile impact resistance of FPAFC was assessed in line with penetration depth, front and rear damage surface area, weight loss, damage ratio and failure pattern. Additionally, a simplified analytical model was introduced to compute the ejected composite mass from the tested specimens. The results revealed that the addition of steel fibre in a single layer FPAFC exhibited an increasing compressive strength trend compared to the two/three-layered FPAFC. Furthermore, increasing the dosage of fibre at the bottom and top layers of FPAFC with a hybrid combination alleviates the spalling with an increasing number of impacts. The results from this research offer the reference information for more detailed research and studies of FPAFC under low-velocity projectile impact.

Impact response of nanoparticle reinforced 3D woven spacer/epoxy composites at cryogenic temperatures

2021 ◽  
pp. 002199832110370
Author(s):  
Ferhat Yıldırım ◽  
Ahmet Caner Tatar ◽  
Volkan Eskizeybek ◽  
Ahmet Avcı ◽  
Mustafa Aydın
Keyword(s):  
Composite Structures ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Woven Composites ◽  
Cryogenic Temperatures ◽  
Low Velocity ◽  
Impact Performance ◽  
Fiber Reinforced Polymer Composites ◽  
3D Woven Composites ◽  
The Impact

Fiber-reinforced polymer composites serving in harsh conditions must maintain their performance during their entire service. The cryogenic impact is one of the most unpredictable loading types, leading to catastrophic failures of composite structures. This study aims to examine the low-velocity impact (LVI) performance of 3D woven spacer glass-epoxy composite experimentally under cryogenic temperatures. LVI tests were conducted under various temperatures ranging from room temperature (RT) to −196°C. Experimental results reveal that the 3D composites gradually absorbed higher impact energies with decreasing temperature. Besides, the effect of multi-walled carbon nanotube and SiO2 nanofiller reinforcements of the matrix on the impact performance and the damage characteristics were further assessed. Nanofiller modification enhanced the impact resistance up to 30%, especially at RT. However, the nanofiller efficiency declined with decreasing temperature. The apparent damages were visually examined by scanning electron microscopy to address the damage formation. Significant outcomes have been achieved with the nanofiller modification regarding the new usage areas of 3D woven composites.

Improvement of Biocomposite Performance under Low-Velocity Impact Test - A Review

2021 ◽  
Vol 893 ◽  
pp. 67-74
Author(s):  
Usha Kiran Sanivada ◽  
Gonzalo Mármol ◽  
Francisco P. Brito ◽  
Raul Fangueiro
Keyword(s):  
Composite Structures ◽  
Impact Test ◽  
Impact Resistance ◽  
Vital Role ◽  
Low Velocity Impact ◽  
Efficient Design ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Tests ◽  
The Impact

The study of the impact energy and the composite behaviour plays a vital role in the efficient design of composite structures. Among the various categories of impact tests, it is essential to study low-velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behaviour must be addressed specifically for improving their applications in the transport industry. The main aim of this paper is to provide a comprehensive review of the work focusing on the assessment of biocomposites performance under low impact velocity, the different deformations, and damage mechanisms, as well the methods to improve the impact resistance.

The influence of fibre orientation in aluminium–carbon laminates on low-velocity impact resistance

2017 ◽  
Vol 52 (8) ◽  
pp. 1005-1016 ◽  
Author(s):  
Patryk Jakubczak ◽  
Jarosław Bienias ◽  
Barbara Surowska
Keyword(s):  
Energy Absorption ◽  
Fibre Orientation ◽  
Impact Resistance ◽  
Bending Stiffness ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Fibre Metal ◽  
The Impact

The objective of this study was to assess the influence of fibre orientation in hybrid fibre metal laminates based on aluminium and carbon fibres on the impact of low-velocity impact. The analysis was conducted on the basis of fibre metal laminate impact resistance criteria, including impact force, energy absorption, bending stiffness, damage area and failure. To assess the resistance of various aluminium–carbon laminates, qualitative and quantitative evaluation criteria were employed, including the shape of the force–time curve, characteristic impact forces, energy absorption, bending stiffness, damage area and external failure analysis. Among others, authors concluded that no explicit influence of the composite layer fibre orientation on the shape and value of characteristic forces was observed. It was found that the fibre orientation and the changing number of interfaces of low durability show no explicit influence on the size and shape of delaminations.

scholarly journals Effect of Uniaxial Fatigue Aging and Fabric Orientation on Low Impact Velocity Response of Glass Fibers/Elium Acrylic Composite Laminates

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4089
Author(s):  
Tomasz Libura ◽  
Rodrigue Matadi Boumbimba ◽  
Alexis Rusinek ◽  
Zbigniew L. Kowalewski ◽  
Tadeusz Szymczak ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Impact Energy ◽  
Composite Structures ◽  
Glass Fibers ◽  
Impact Resistance ◽  
Woven Fabric ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Engineering Structures ◽  
The Impact

Impact resistance is one of the most critical features of composite structures, and therefore, its examination for a new material has a fundamental importance. This paper is devoted to the characterization of the fully recyclable thermoplastic ELIUM acrylic resin reinforced by glass fabric woven, which belongs to a new category of materials requiring advanced testing before their application in responsible elements of engineering structures. Its high strength, low weight as well as low production cost give excellent opportunities for its wide application in the automotive industry as a replacement of the thermoset-based laminates. The study presents an experimental work concerning the effect of damage due to low and high cyclic fatigue aging of two groups of specimens, first with the woven fabric orientations of [0°/90°]4 and secondly with [45°/45°]4, on the low impact velocity properties. The impact resistance was measured in terms of load peak, absorbed energy, penetration threshold and damage analysis. The low velocity impact results indicate that the uniaxial cyclic loading (fatigue aging) of the material leads to the reduction of impact resistance, especially at the high impact energy levels. Scanning Electron Microscopy (SEM) and Computed Tomography (CT) scan observations reveal that the damage area grows with the increase of both strain amplitude and impact energy.

Low-Velocity Flexural Impact Analyses of Functionally Graded Sandwich Beams Using Finite Element Modeling

2018 ◽  
Vol 10 (10) ◽  
pp. 1850113 ◽  
Author(s):  
Kemal Arslan ◽  
Recep Gunes
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Impact Energy ◽  
Considerable Effect ◽  
Functionally Graded ◽  
Low Velocity ◽  
Compositional Gradient ◽  
Number Of Layers ◽  
Impact Side ◽  
The Impact

A comparative numerical investigation on low-velocity impact response of a metal/ ceramic functionally graded sandwich beam (FGSB) is performed by the commercial finite element (FE) software, LS-DYNA[Formula: see text]. The mechanical properties of the FG core are represented by a power-law depending on the volume fractions of the constituents. The effective elastic properties and elastoplastic behavior of the FG core are defined by Mori–Tanaka method and TTO (Tamura–Tomota–Ozawa) model, respectively. The effects of number of layers, compositional gradient, impact energy, and impact side are investigated. The simulation results indicated that both number of layers and compositional gradient have almost no effect on the kinetic energy history. In other respects, the compositional gradient exhibits a considerable effect, and the number of layers has a minor effect on the contact force history. Increasing impact energy does not have a considerable effect in terms of number of layers whereas it exhibits a significant effect in terms of compositional gradient on the percentage difference between the peak contact forces. Finally, the impact side does not influence the contact force history for all number of layers and compositional gradients.

Experimental study on structure optimization of functionally graded sandwich plates under ballistic impact

2020 ◽  
Vol 54 (26) ◽  
pp. 3967-3980
Author(s):  
Murat Aydin ◽  
M Kemal Apalak ◽  
Z Gül Apalak
Keyword(s):  
Volume Fraction ◽  
Plate Thickness ◽  
Functionally Graded ◽  
Ballistic Performance ◽  
Pressing Method ◽  
Projectile Impact ◽  
Ballistic Resistance ◽  
Impact Surface ◽  
Number Of Layers ◽  
Ballistic Tests

In this study, the ballistic performance of Al6061-SiC functionally graded sandwich plate (FGSP) with varying number of layers and volume fractions was examined experimentally. For this purpose, the two outmost layers of the FGSP were designed to be aluminum and the volume fraction of remaining constituents was gradually changing in intermediate layers through the plate thickness. The specimen plates were manufactured via powder stacking-hot pressing method. Ballistic tests of specimens were conducted with a single-stage gas gun, shooting 0.3 caliber fragment simulated projectiles onto specimens. After the ballistic tests, deformation and damage mechanisms in the front and rear surfaces were examined and ballistic performance evaluation was carried out in terms of depth of penetration of the projectile measurements. Results showed that the composition of the projectile impact surface, which was beneath the top aluminum layer, had a considerable effect on ballistic resistance capability. A volume fraction of ceramic constituent greater than 60% in the projectile impact surface reduced the ballistic performance of the specimen. Likewise, a decreasing volume fraction of ceramic constituent of projectile impact surface below 60% increased projectile penetration. Furthermore, increasing the number of layers within the functionally graded region did not have a significant effect on the ballistic resistance of the FGSPs.

Damage evaluation of laminated composites under low-velocity impact tests using acoustic emission method

2016 ◽  
Vol 51 (4) ◽  
pp. 479-490 ◽  
Author(s):  
Ali Mahdian ◽  
Jalal Yousefi ◽  
Mehrdad Nazmdar ◽  
Navid Zarif Karimi ◽  
Mehdi Ahmadi ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Composite Structures ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Transform Method ◽  
Static Test ◽  
Velocity Impact ◽  
Damage Area ◽  
Impact Tests

The main goal of this investigation is to characterize the damage in laminated composites under low-velocity impact tests using a new cost-effective approach. To this aim, a quasi-static test was first carried out to obtain initial information about impact tests. Low-velocity impact tests were then applied in unidirectional glass/epoxy composite specimens, and acoustic emission signals were captured during impact events. Next, acoustic emission signals were analyzed using wavelet approach to distinguish released energy related to each distinct damage mechanism. Besides, an approach was provided to estimate threshold impact energy from the quasi-static test, beyond which damage significantly extends. As a final point, the acoustic emission-based procedure using wavelet transform method was proposed to predict the total damage area. Finally, it was found that this acoustic emission methodology can be a capable approach in damage characterization under impact loads in composite structures.

scholarly journals Impact Resistance of Fibre Reinforced Composite Railway Freight Tank Wagons

2021 ◽  
Vol 5 (6) ◽  
pp. 152
Author(s):  
George Edward Street ◽  
Preetum Jayantilal Mistry ◽  
Michael Sylvester Johnson
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Biaxial Loading ◽  
Impact Damage ◽  
Impact Resistance ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Fibre Direction ◽  
Reinforced Composite

The use of fibre reinforced composite materials is one method by which the lightweighting of rail vehicles can be achieved. However, the issue of impact damage, amongst other challenges, limits their safety certification. This issue is accentuated by the high levels of loading a rail vehicle may be subjected to during service. This paper addresses the significance of pre-tension on large composite structures, specifically for a composite redesign of a pressure vessel for a freight tank wagon. Preloading was determined to be detrimental to the overall impact resistance of a large composite vessel. At 15.71 J of impact energy, there was a 22% increase in mean absorbed energy for a uniaxially loaded panel over an unloaded panel. However, there was only a 4% difference in penetration depth between uniaxial and biaxial loading. A novel finding from these results is that the effects of preloading are more profound if the loading does not act parallel to a principal fibre direction. Matrix cracking and delaminations are the most common failure modes observed for specimens under low-velocity impact and are intensified by preload.

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