scholarly journals Free Vibration Analysis of Functionally Gradient Sandwich Composite Plate Embedded SMA Wires in Surface Layer

2020 ◽  
Vol 10 (11) ◽  
pp. 3921
Author(s):  
Yizhe Huang ◽  
Lin Li ◽  
Zhichao Xu ◽  
Chaopeng Li ◽  
Kuanmin Mao
Keyword(s):  
Surface Layer ◽  
Dynamic Behavior ◽  
Composite Plate ◽  
Sandwich Plate ◽  
Volume Fraction ◽  
Core Layer ◽  
Sandwich Composite ◽  
Composition Gradient ◽  
Gradient Distribution ◽  
The Core

In this paper, a new type of composite gradient sandwich plate structure is proposed, which embeds the pre-strained shape memory alloy (SMA) into the surface layer and the core layer composed of epoxy resin and graphite-reinforced materials. In the core layer, graphite-reinforced material has a continuous gradient distribution along the thickness direction of the sandwich plate. Dynamic behavior of composite gradient sandwich plate in thermal environment is investigated. The equations of motion and frequency equation are derived based on the Reddy shear deformation theory and the constitutive equation for a composite sandwich plate, via the Hamilton principle. Some analytical study is depicted to provide an insight into the effects of volume fraction of material composition, gradient distribution of graphite in the core layer, and pre-strain of SMA in the surface layer on the dynamic behavior of a sandwich composite plate. This study investigates the modal performance of a sandwich composite plate with two aspects, a gradient core layer of graphite-reinforced material and surface layer-embedded SMA wires, which provide a new design idea for dynamic behavior of sandwich plates.

Impact of blast and mechanical loads on the shear deformable stiffened sandwich plate with an auxetic core layer in thermal environment

2021 ◽  
pp. 109963622110219
Author(s):  
Vu Thi Thuy Anh ◽  
Vu Dinh Quang ◽  
Nguyen Dinh Duc ◽  
Pham Ngoc Thinh
Keyword(s):  
Dynamic Behavior ◽  
Elastic Foundation ◽  
Nonlinear Dynamic ◽  
Sandwich Plate ◽  
Thermal Environment ◽  
Core Layer ◽  
Mechanical Loads ◽  
Environment Temperature ◽  
Nonlinear Dynamic Behavior ◽  
Fgm Layer

By using the first order shear deformation theory (FSTD), this paper presents the results of the nonlinear dynamic behavior and natural frequencies of sandwich plate supported by elastic foundations in thermal environment and subjected to mechanical load and blast loading. This work takes advantage of the sandwich plate configuration with three layers: graphene platelet –reinforced composite (GPL) layer – auxetic layer – FGM layer, to analyze the dynamic and vibration problem, in which the auxetic core layer has a negative Poisson's ratios and the FGM layer is reinforced by stiffeners made of full metal or full ceramic depending on a situation of stiffeners at the metal-rich or ceramic-rich side of the plate respectively. Corresponding to the combination of material layers, the mechanical quantities of the problem are processed and calculated to suit the structure and reinforcement conditions. Numerical results are provided to explore the influences of geometrical parameters, elastic foundation parameters, GPL volume fraction, blast and mechanical loads on the nonlinear dynamic behavior and vibration of sandwich plate resting on elastic foundation and in thermal environment. In addition, the study is not only assumed that the material properties depend on environment temperature variation, but also considered the thermal stresses in the stiffeners, as well as considered the effect of imperfections in the original shape of the structure.

Electric field effect on dynamic analysis of smart porosity-dependent nanocomposite sandwich plate resting on silica aerogel foundation considering carbon nanotubes agglomeration

2019 ◽  
Vol 30 (18-19) ◽  
pp. 2651-2669
Author(s):  
Mohammad Hossein Zamani ◽  
Mohammad Heidari-Rarani ◽  
Alireza Ariaei
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Silica Aerogel ◽  
Sandwich Plate ◽  
Core Layer ◽  
Smart Structure ◽  
Geometrical Parameters ◽  
Equivalent Material ◽  
Electric Field Effect ◽  
The Core

In this study, the influence of carbon nanotubes agglomeration is investigated on the electroelastic dynamic behavior of a sandwich plate. The smart sandwich plate consists of functionally graded porous layer as the core and piezoelectric layers as the face sheets, which is subjected to the harmonic electrical loading. In order to take into account the continuum model for the silica aerogel foundation of the smart structure, the modified Vlasov’s model is applied. The porosity distribution of the core layer varies non-uniformly throughout the thickness due to the non-uniform function. The equivalent material properties of nanocomposite core layer are determined using the Eshelby–Mori–Tanaka approach, in which the influence of carbon nanotube agglomeration is considered. For modeling the electroelastic fact sheets behavior, the piezoelasticity theory is adopted. On the basis of non-polynomial shear and normal deformation theory, the governing equations of motion are inferred applying the Hamilton’s principle and the obtained equations are solved by an iterative procedure. The verification is accomplished through the available results in the literature and the influences of carbon nanotube agglomeration, different geometrical parameters, porosity index, and applied voltage are assessed on the dynamic deflection of nanocomposite sandwich plate.

Bending and impacting of sandwich composites with a corrugated paper core layer

2018 ◽  
Vol 32 (19) ◽  
pp. 1840057 ◽  
Author(s):  
Jieng-Chiang Chen
Keyword(s):  
Core Layer ◽  
Test System ◽  
Absorption Capacity ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Hot Press ◽  
Jute Fabric ◽  
The Core ◽  
The Impact ◽  
Corrugated Paper

The bending and impacting characteristics of sandwich composites containing corrugated paper (CP) as a core layer are discussed herein. The core layer of the sandwich composite was fabricated with CP-reinforced polylactic acid (PLA) resin. The core layer was then stacked with jute fabric and PLA films on the top and bottom surfaces to fabricate the sandwich composites. Two composites [CP-reinforced PLA composite (CP/PLA composite)] and jute fabric/PLA sandwich composite with CP as a core layer [J/PLA/CP composite] were developed in this study. To manufacture the CP/PLA composite core layer, a dipping bath was used for impregnating the paper with a molten PLA solution. The resin film method combined with a hot press was used to produce the jute fabric/PLA/CP sandwich composites. A material test system (MTS810) was used to study the bending properties of the composites. Further, an IZOD impacting instrument was used to examine the impacting characteristics of the composites. Both the CP/PLA and jute fabric/PLA/CP sandwich composites increase the energy absorption capacity in the impact test.

Static and Dynamic Behavior of Nanotubes-Reinforced Sandwich Plates Using (FSDT)

2019 ◽  
Vol 57 ◽  
pp. 117-135 ◽  
Author(s):  
Aicha Draoui ◽  
Mohamed Zidour ◽  
Abdelouahed Tounsi ◽  
Belkacem Adim
Keyword(s):  
Carbon Nanotube ◽  
Dynamic Behavior ◽  
Sandwich Plate ◽  
Volume Fraction ◽  
Face Sheet ◽  
Sandwich Plates ◽  
Composite Sandwich ◽  
Aspect Ratios ◽  
Reinforced Composite ◽  
Composite Sandwich Plates

Based on the first order shear deformation plate theory (FSDT) in the present studie, static and dynamic behavior of carbon nanotube-reinforced composite sandwich plates has been analysed. Two types of sandwich plates, namely, the sandwich with face sheet reinforced and homogeneous core and the sandwich with homogeneous face sheet and reinforced core are considered. The face sheet or core plates are reinforced by single-walled carbon nanotubes with two types of distributions of uniaxially aligned reinforcement material which uniformly (UD-CNT) and functionally graded (FG-CNT). The analytical equations are derived and the exact solutions for bending and vibration analyses of such type’s plates are obtained. The mathematical models provided and the present solutions are numerically validated by comparison with some available results in the literature. Influence of Various parameters of reinforced sandwich plates such as aspect ratios, volume fraction, types of reinforcement and plate thickness on the bending and vibration analyses of carbon nanotube-reinforced composite sandwich plates are studied and discussed. The findings suggest that the (FG-CNT) face sheet reinforced sandwich plate has a high resistance against deflections compared to other types of reinforcement. It is also revealed that the reduction in the dimensionless natural frequency is most pronounced in core reinforced sandwich plate.

scholarly journals Proposal of Sandwich Composite from Bioresource and Polystyrene Waste Materials

2018 ◽  
Vol 7 (4.20) ◽  
pp. 329
Author(s):  
Aqil M. ALmusawi ◽  
Remy Lachat ◽  
Dominique Chamoret ◽  
Kokou Atcholi ◽  
Sagnaba Soulama
Keyword(s):  
Building Materials ◽  
Core Layer ◽  
Thermoplastic Composite ◽  
Sandwich Composite ◽  
Individual Layer ◽  
The Core ◽  
Composite Layers ◽  
Polystyrene Matrix ◽  
Thermoforming Process ◽  
Polystyrene Waste

Lately there is a renewed interest in the use of bio-resource materials for the production of ecological, sustainable and inexpensive building materials. Sandwich composite of minimum plastic matrix was manufactured, this was achieved by using the Thermoforming process in two steps. In the first step, the core layer was made when thermo pressed 100% hemp Shive particles under a high pressure. The second step was accomplished by wrapping the core layer with two thermoplastic composite layers of 60% of hemp tissue and 40% recycled Polystyrene. Interestingly, through the first step, elevated temperature treated the core surface (hydrophilic) and gave it greater adherence to the Polystyrene matrix (hydrophobic). Mechanical properties of this proposed sandwich composite of 80 % bio-resource were approximately four times of the Polystyrene resistance. Furthermore, the microscopic study was performed to investigate the bonding of the different components, especially for the binderless core layer. Each individual layer and the sandwich form were mechanically investigated, and the finite element method, via ANSYS, was used to illustrate the stresses in the sandwich structure.   

Thermal postbuckling behavior of CNT-reinforced composite sandwich plate models resting on elastic foundations with tangentially restrained edges and temperature-dependent properties

2019 ◽  
Vol 33 (10) ◽  
pp. 1396-1428 ◽  
Author(s):  
Vu Thanh Long ◽  
Hoang Van Tung
Keyword(s):  
Sandwich Plate ◽  
Volume Fraction ◽  
Effective Properties ◽  
Core Layer ◽  
Iteration Algorithm ◽  
Sandwich Plates ◽  
Postbuckling Behavior ◽  
Temperature Dependent ◽  
Elastic Foundations ◽  
Thermal Postbuckling

Buckling and postbuckling behaviors of sandwich plates reinforced by single-walled carbon nanotube (CNT), rested on elastic foundations and subjected to uniform temperature rise, are investigated in this article. CNT is embedded into matrix phase through uniform or functionally graded distributions. The properties of constituent materials are assumed to be temperature-dependent, and effective properties of nanocomposite are determined by extended rule of mixture. Two models of sandwich plates with face sheets and core layer reinforced by CNTs are presented. Formulations are based on the first-order shear deformation theory taking geometrical nonlinearity, initial geometrical imperfection, plate-foundation interaction, and elasticity of tangential edge constraints into consideration. Analytical solutions of deflection and stress function are assumed, and Galerkin method is applied to derive nonlinear temperature–deflection relation from which buckling temperatures and thermal postbuckling paths are obtained through an iteration algorithm. Numerical examples show the effects of CNT volume fraction, distribution patterns, in-plane edge constraint, elastic foundations, geometrical ratios, initial imperfection, and temperature dependence of properties on thermal postbuckling behavior of nanocomposite sandwich plates. The most important finding is that sandwich plate constructed from CNT-poor nanocomposite core layer and thin homogeneous face sheets with partially movable edges bring the best capacities of thermal buckling resistance and postbuckling load carrying.

Shear actuation-based hybrid damping treatment of sandwich structures using a graphite particle-filled viscoelastic layer

2021 ◽  
pp. 1045389X2110026
Author(s):  
Abhay Gupta ◽  
Satyajit Panda ◽  
Rajidi Shashidhar Reddy
Keyword(s):  
Graphite Particle ◽  
Sandwich Plate ◽  
Volume Fraction ◽  
Shear Mode ◽  
Passive Damping ◽  
Graphite Particles ◽  
The Core ◽  
Active Layers ◽  
Plate Strip ◽  
Hybrid Damping

In this work, the effectiveness of a shear actuation-based hybrid active-passive damping treatment is investigated by incorporating the inclusion of graphite particles within the viscoelastic damping layer. The study is performed through the flexural vibration analysis of a sandwich plate-strip where the core is made of a laminate of active layers and graphite particle-filled viscoelastic layers in two different stacking sequences. The active layers are comprised of shear mode piezoelectric actuator patches that are activated according to a shear-based velocity feedback control strategy. The analysis is performed by deriving a closed-loop finite element model of the sandwich plate-strip, and it reveals that the hybrid damping is significantly dependent on the stacking sequence of active and passive damping layers at the core. The inclusion of graphite particles not only provides augmented passive damping but also causes enhanced transfer of shear actuation force from the active layers to other layers. As a result, a significantly improved shear actuation-based hybrid active-passive damping is achieved due to the inclusion. The effectiveness of this hybrid damping in attenuation of resonant displacement-amplitude is also presented by configuring the volume fraction of graphite particles and shear actuator patches in an optimal manner.

scholarly journals Electromagnetic interference shielding characteristics of a core layer-coated fabric with excellent hand-feel characteristics

2020 ◽  
Vol 15 ◽  
pp. 155892502095973
Author(s):  
D Xu ◽  
WW Yang ◽  
HM Jiang ◽  
H Fan ◽  
KS Liu
Keyword(s):  
Surface Layer ◽  
Electromagnetic Interference ◽  
Core Layer ◽  
Polyvinyl Butyral ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Electron Microscopic ◽  
The Core ◽  
Coated Fabric

Electromagnetic shielding fabric (ESF) is a novel electromagnetic shielding product with portability, flexibility, and good mechanical properties. However, the existing ESFs suffer from poor washing fastness of coating and poor comfort performance in terms of hand-feel characteristic. In this study, a core layer-coated yarn (CLCY) was successfully spun using a carboxylic acid-functionalized multi-walled carbon nanotube/polypyrrole/Fe3O4 composite suspension with polyvinyl butyral as an adhesive agent. To better explore the properties, the original fabric and treated fabrics, viz., core layer-coated fabric (CLCF) and surface layer-coated fabric (SLCF), were characterized by several methods. Scanning electron microscopic observations revealed that the coating was on the core layer in CLCF. In addition, the Fourier-transform infrared spectroscopy and X-ray diffraction spectroscopy results revealed that the composition of the coating corresponds with that in the multi-composite suspension. Moreover, the coating of CLCY formed a conductive path with good conductivity in the core layer, but the conductivity of the coating on the surface layer of SLCF deteriorated sharply after washing. Further, compared with the original fabric and SLCF, CLCF has highest breaking strength (after 10 washes), and keeps a relatively good hand-feel characteristic. Finally, the evaluated electromagnetic interference shielding characteristics reveal that the fastness of coating affects the electromagnetic shielding effectiveness, suggesting that the wrapped protection of outside staple fibers in CLCF reduce the loss of coating in the core layer during washing. However, the coating on the surface layer in SLCF could be washed away easily.

Bending and compression of glass fabric-corrugated paper–epoxy sandwich composites

2020 ◽  
Vol 34 (07n09) ◽  
pp. 2040003
Author(s):  
Jieng-Chiang Chen ◽  
Xiu-Zhi Yang
Keyword(s):  
Bending Strength ◽  
Core Layer ◽  
Test System ◽  
Glass Fabric ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
The Core ◽  
Compression Properties ◽  
Composite Glass ◽  
Corrugated Paper

The manufacturing procedures of sandwich composites containing corrugated paper (CP) as a core layer and covered with glass fabrics are discussed herein. The core layer of the sandwich composite was fabricated with CP-reinforced epoxy (E) resin and then stacked with glass fabric on the top and bottom surfaces to fabricate the sandwich composites. Three composites [a CP-reinforced E (CP/E) composite, glass fiber nonwoven mat (GN) sandwich composite with a CP core layer (GN/E/CP) and glass mesh fabric (GM) sandwich composite with a CP core layer (GM/E/CP)] were developed in this study. The bending and compression properties of these sandwich composites were measured on a materials test system. Experimental results revealed that the bending strength of the GN/E/CP sandwich composite was approximately 45% and 150% higher than those of the GM/E/CP and CP/E sandwich composites, respectively.

scholarly journals Numerical Analysis of Sandwich Composite Deep Submarine Pressure Hull Considering Failure Criteria

2019 ◽  
Vol 7 (10) ◽  
pp. 377 ◽  
Author(s):  
Mahmoud Helal ◽  
Huinan Huang ◽  
Defu Wang ◽  
Elsayed Fathallah
Keyword(s):  
Numerical Analysis ◽  
Core Layer ◽  
Failure Criteria ◽  
Control Surface ◽  
Sandwich Composite ◽  
Minor Role ◽  
Analysis And Design ◽  
The Core ◽  
Hull Design ◽  
Core Thickness

The pressure hull is the primary element of submarine, which withstands diving pressure and provides essential capacity for electronic systems and buoyancy. This study presents a numerical analysis and design optimization of sandwich composite deep submarine pressure hull using finite element modeling technique. This study aims to minimize buoyancy factor and maximize deck area and buckling strength factors. The collapse depth is taken as a base in the pressure hull design. The pressure hull has been analyzed using two composite materials, T700/Epoxy and B(4)5505/Epoxy, to form the upper and lower faces of the sandwich composite deep submarine pressure hull. The laminated control surface is optimized for the first ply failure index (FI) considering both Tsai–Wu and maximum stress failure criteria. The results obtained emphasize an important fact that the presence of core layer in sandwich composite pressure hull is not always more efficient. The use of sandwich in the design of composite deep submarine pressure hull at extreme depths is not a safe option. Additionally, the core thickness plays a minor role in the design of composite deep submarine pressure hull. The outcome of an optimization at extreme depths illustrates that the upper and lower faces become thicker and the core thickness becomes thinner. However, at shallow-to-moderate depths, it is recommended to use sandwich composite with a thick core to resist the shell buckling of composite submarine pressure hull.

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