The effect of distribution of aluminum layer through the thickness of fiber metal laminates (FMLs) on their low velocity impact response was studied. The FMLs were prepared using aluminum 2024-T3 ...layers (0.3, 0.4, 0.6 mm thickness) and glass fiber reinforced epoxy (two layers of 0° and 90° each) through hand layup followed by vacuum bagging. The four different layups considered had metallic layers placed at different locations through the thickness while maintaining the total metal layer thickness constant. The FMLs were subjected to low-velocity impact using a drop weight testing machine. The performance of FMLs was evaluated using different parameters such as maximum force, energy absorbed, damage degree, dent depth and maximum deflection. Among the four FMLs, it was observed that the FML 2/1–0.6 in which the composite layers were stacked together had lower levels of cracking and deformation and recorded the highest force for the same impact energy level, whereas the FML 4/3–0.3 in which two adjacent composite layers having different fiber orientations were separated by metallic layer recorded the lowest force and maximum cracking and deformation. The lateral spread of delamination and interlayer opening was comparatively greater for 2/1–0.6 when compared to 4/3–0.3, indicating that distributing the aluminum layers in the FML can decrease the lateral spread of damage within the FML.
•The low velocity impact behavior of aluminum based fiber metal laminates (FMLs) has been investigated using drop tower impact tester.•Internal damages are identifying by slicing the specimen and the same are correlated with their corresponding displacement response.•Effect of metal layer distribution across the thickness of FMLs on the low velocity impact response of FMLs is brought out.•Distribution of aluminum layers through the thickness affects both damage pattern and damage degree.•Opening of delamination between the different layers was significantly affected by the distribution of aluminum layers in the FML.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The current study focuses on the interaction occurring between middle metal/composite layers of the GLARE during the impact loading scenario.•The study is quantified by including different GLARE ...standards with dissimilar metal layer thicknesses to notice the effect on the damage resistance. Energy based comparison further highlights the pros and cons of adding one or two such interfaces inside the laminates.•Placement of metallic layers inside the GLARE laminate decreases its flexural strength but increases the energy dissipation in plasticity.•We believe that the findings from present study will be useful for structural engineer/manufacturer in making their careful choice in accordance with their requirement.
This study focuses on the effect of metal layer distribution in glass fibre reinforced aluminium laminates (GLARE) subjected to low velocity impact. Four GLARE variants specimens were considered in which the metal layers of different thicknesses were placed at various positions in the layup while keeping the same total metal layer thickness. Experiments and Finite element (FE) analysis were performed to understand the behaviour of the GLARE specimens. A user written material subroutine VUMAT which incorporates Hashin failure criteria along with Puck's action plane concept were used to predict the response of the composite layers. The damage was evolved for each failure mode using the exponential damage evolution law. Interface delamination between the layers was initiated by cohesive surface behaviour which includes the friction effect between the plies. It was found that placement of thinner metal layer on top of the laminate and its distribution inside the layup lowers the impact resistance of GLARE. Moreover, the patterns of delamination are also affected by the placement of metal layer within the laminates. It was further shown that the propagation direction of delamination is governed by the fibre direction of lower ply of the interface.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The low-velocity impact resistance of fiber metal laminates (FMLs) is investigated. FMLs with titanium alloy Ti-6Al-4V sheets and glass fiber/epoxy layers are fabricated using the hand layup ...technique, exhibiting the same total metal layer thickness. A drop tower is used to produce a low-velocity impact on the FMLs. FML with outermost metallic layers exhibits comparatively higher lateral spreading and interlayer delamination opening contrary to FML with more metallic layers. This is also observed in high-velocity impact. The low-velocity impact resistance of titanium-based FMLs seems higher than aluminum-based FMLs. This is also noticed in high-velocity impact for former and latter FMLs.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The high strain rate tensile response of titanium-based fiber metal laminates (FMLs), consisting of layers of titanium Ti-6Al-4V alloy sheet and glass fiber reinforced composites, is examined. A hand ...layup method is used to fabricate four different layups of FMLs, exhibiting the same thickness of the total metal layer. A split Hopkinson tensile bar apparatus is used to load titanium and composite under a high strain rate to obtain baseline data. High-speed digital image correlation is used to measure the strain directly on the specimen gage region. The elastic-plastic response of FMLs up to maximum stress is predicted by the classical laminated plate model and orthotropic plasticity model. This is followed by a behavior considering the mechanics of delamination. The results show that the layup sequence of titanium-based FMLs considerably affects the failure behavior of composites following ultimate strength. This strength increases at high strain rates and seems higher for titanium-based FMLs than aluminium-based FMLs. This is primarily caused by the rate-dependent response of the titanium and composite. The failure strain of glass fiber reinforced epoxy (GFRP) constituent, failure strain, and toughness of FMLs are affected by isolating composite layers by metallic layers within FMLs and are found to be rate sensitive. Isolation of composite layers from one another by metallic layers results in more progressive failure of FMLs. The proposed models are validated with experiments of aluminium-based FMLs available in the literature.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
•Part I explores the projectile impact response and damage of titanium-based fiber metal laminates (FMLs) using air gun set up.•The damage pattern, energy absorption, and opening of delamination ...between different layers are affected by distributing titanium layers through the thickness.•The ballistic resistance of FMLs is found to be independent of the dispersion of metallic layers within FMLs.•The lateral delamination spread, interlayer opening, and global bending deformation of titanium-based FMLs seem lower than aluminium-based FMLs.
This two-part article examines the distribution of metallic layers through the thickness of fiber metal laminates (FMLs) on their response and damage when subjected to high-velocity projectile impact. Glass fiber/epoxy and Ti-6Al-4V titanium alloy sheets are used to obtain four different layups of FMLs fabricating by the hand layup process and exhibiting the same thickness of the total metal layer. Part I deals with experimental investigations of fully clamped square FMLs normally impacting at the center by hemispherical steel projectile using compressed air gun set up. Different parameters are considered to evaluate the FMLs’ performance, which includes damage degree, first cracking energy, crack length, deformation profile, and damage developed on the surface and inside the laminate. The results indicate that the highest permanent deformation and cracking are exhibited by FML 4/3-0.3, exhibiting separation of composite layers with different orientations by the metallic layer. The other FMLs exhibit lower and approximately similar permanent deformations. However, lower cracking and a relatively higher lateral delamination spread and opening of the interlayer are exhibited by FML 2/1-0.6 in which composite layers are arranged together than FML 4/3-0.3, signifying that the damage spreading laterally can be reduced by dispensing titanium layers. The ballistic resistance is found to be similar for FMLs. The levels of permanent deformation, cracking, and delamination with their opening and spreading are lesser for titanium-based FMLs than aluminium-based FMLs. The ballistic response of FMLs will be evaluated using analytical modeling in an accompanying study (Part II).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The present study is focused on the synthesis of silver nanoparticles (AgNPs) utilizing endophytic fungus
Talaromyces purpureogenus
, isolated from
Taxus baccata
Linn. Extracellular extract of
...Talaromyces purpureogenus
has shown occurrence of secondary metabolites viz. terpenoids and phenols. Gas chromatography-mass spectroscopy analysis showed the presence of 16 compounds. Techniques like Ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, field emission gun scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction were employed to characterize the synthesized AgNPs. UV–Vis spectroscopy showed sharp peaks at 380–470 nm which indicates the presence of metallic silver. FTIR analysis showed the presence of various functional groups like phenols, hydroxyl groups, and primary amines. In DLS, Z-average size and PdI of synthesized AgNPs were 240.2 r.nm and 0.720 respectively, with zeta potential − 19.6 mV. In FEG-SEM and HRTEM the spherical AgNPs showed diameter in the range of 30–60 nm. In EDS analysis the weight percent of Ag is 67.26% and atomic percent is 43.13%. From XRD analysis the size of AgNPs was found to be 49.3 nm with face-centered cubic crystalline nature of fungal synthesized AgNPs. These nanoparticles have shown significant antibacterial activity against tested strains viz.
Listeria monocytogenes
(13 ± 0.29 mm),
Escherichia coli
(17 ± 0.14 mm),
Shigella dysenteriae
(18 ± 0.21 mm) and
Salmonella typhi
(14 ± 0.13 mm). These synthesized AgNPs have shown effective free radical scavenging activity against 2,2′-diphenyl-1-picrylhydrazyl. The present study showed that the endophytic fungus
Talaromyces purpureogenus
can be used as a prominent source to synthesize AgNPs by using biological, ecofriendly, and in a non-toxic way accompanied by antibacterial and antioxidant properties which further can reduce the harvesting pressure faced by
Taxus baccata.
Graphical Abstract
The effect of the distribution of aluminum layer through the thickness of fiber metal laminates (FMLs) on their projectiles impact response is studied using high speed 3D digital image correlation ...technique (DIC). The FMLs consisting of aluminum alloy 2024-T3 sheets of thicknesses 0.3 mm, 0.4 mm, and 0.6 mm and glass fiber reinforced epoxy layers (two layers with each of 0° and 90°) were prepared by the hand layup process followed by vacuum bagging. The metallic layers are placed at different locations through the thickness of four different layups while keeping the total metal layer thickness constant. The hemispherical and conical nose projectiles of the same mass are impacted normal to the FMLs plate using nitrogen gas gun. The performance of the FMLs is evaluated using different parameters such as the deformation history, residual deformation and also the surface and internal damages. FML 4/3–0.3 in which the two adjacent composite layers with different fiber orientations separating by an aluminum layer exhibited the highest deformation with hemispherical projectile impact for the same impact energy level. The deformation was found to be lower and nearly same for the other three FMLs. This observation is also noticed in the case of drop weight impact (low velocity impact). The FML 2/1–0.6 in which the composite layers were stacked together exhibited a comparatively higher lateral spread of delamination and interlayer opening with hemispherical projectile impact when compared to FML 4/3–0.3, indicating that the lateral spread of damage within the FML can be decreased by distributing the aluminum layers in the FML. This is also observed in the case of drop weight impact.
•The projectiles impact response of aluminum based fiber metal laminates (FMLs) has been investigated using high speed 3D digital image correlation technique.•Internal damages are identified by slicing the specimen.•Effect of meal layer distribution through the thickness of FMLs on the projectiles impact response of FMLs is brought out.•Damage pattern is affected by distributing the aluminum layers through the thickness with more extent of damage exhibited by projectiles impact.•Hemispherical projectile impact imparts more collateral damage to that of conical projectile.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Part II deals with the dynamic response of titanium-based FMLs undergoing ballistic impact using analytical modeling.•The leading part of the total energy absorption of FMLs is by bending and ...membrane energy absorption associated with the deformation of FML constituents (68 % - 72 %).•Varying placements of the titanium layers affect the partition of the energy absorption of FMLs.•The predicted ballistic resistance parameters of FMLs are found to be in good agreement with experiments.
This two-part article scrutinizes the influence of metal layer distribution through the thickness of titanium-based fiber metal laminates (FMLs) on their high-velocity projectile impact response and damage. The four different layups of FMLs consist of layers of glass fiber/epoxy and Ti-6Al-4V titanium alloy sheets, exhibiting the thickness of the total metal layer the same. Part I presents the experimental investigations of fully clamped FMLs demonstrating performance parameters, damage mechanisms, and ballistic resistance. Part II concerns the ballistic impact behavior of FMLs using analytical modeling, which is based on test results obtained in an accompanying study. An equivalent mass-spring system is used to obtain the transient deformation, ballistic limit, and absorbed energy of the laminate by various mechanisms. Good agreement is obtained between experimental and analytical ballistic limit velocity. The foremost part of the total energy absorption is by bending and membrane energy absorption (68 % - 72 %), with FML 4/3-0.3 absorbing a higher percentage of aforementioned energies followed by that of both FMLs 3/2 and FML 2/1-0.6. The predicted total energy absorption by several damage mechanisms of FMLs at the ballistic limit displays a reasonable matching with experiments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The tensile behavior of fiber metal laminates consisting of layers of aluminum 2024-T3 alloy and glass fiber reinforced composites under high strain rate loading is investigated. Fiber metal ...laminates having four different layups, but all having the same total metal layer thickness, were fabricated using a combined hand lay-up cum vacuum bagging method. The fiber metal laminate specimens were loaded in high strain rate tension using a split Hopkinson tensile bar. The rate-dependent behavior of the glass fiber composite was also obtained as baseline data. The strain on the gage area of the specimen was measured directly using high-speed digital image correlation. Another high-speed camera was used to capture the sequence of damage by viewing the specimen edgewise. The results indicated that the strength of the fiber metal laminates increased at high strain rates primarily due to the rate-dependent behavior of the composite used. The response was also influenced by the distribution of the metallic layers in the fiber metal laminates. The failure in the case where the individual composite layers were separated by metallic layers was more progressive in nature.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The effect of separation of fiber orientation through the thickness of thin composites on their low velocity impact response is studied. The composites are prepared using unidirectional glass fiber ...reinforced epoxy through hand layup followed by vacuum bagging. The two dissimilar layups of composites considered have separation of composite layers with fibers having the same and different orientations through the thickness. The composites are subjected to low velocity impact using a drop-weight testing machine. The composites are evaluated using different performance parameters such as damage degree, first damage and maximum forces, first cracking energy, bending stiffness, elastic strain energy, elastic, residual and maximum displacements, permanent deformation, square-root delaminated area, delamination length and width, and contact duration. Among the two composites, it is observed that 90/-45/45/0 composite in which two layers with fibers having 90° and 0° orientations separating by two layers with fibers having -45° and 45° orientations, levels of deformation are lower and recorded force and square-root delaminated area are higher and lower, respectively for the same level of impact energy. Whereas, in case of 0/90/90/0 composite in which two layers with fibers having 0° orientations separating by two layers with fibers having 90° orientations, recorded force is lower and deformation and square-root delaminated area are higher. The 0/90/90/0 composite is having a comparatively more lateral spread of delamination and inter-layer opening than that of 90/-45/45/0 composite considering extensional and bending stiffnesses along longitudinal (A11, D11) and transverse (A22, D22) directions. This facilitates that lateral spread of damage within composite can be decreased by separating two layers of composite with 90° and 0° fiber orientations by two layers with -45° and 45° fiber orientations, i.e., 90/-45/45/0 composite.
Materials science; Mechanical engineering; Composites; Low velocity impact; Delamination; Energy absorbed; Structural analysis; Composite materials; Materials characterization; Mechanical property; Structural behavior
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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