scholarly journals Design of Laminated Composite Plates with Carbon Nanotube Inclusions against Buckling: Waviness and Agglomeration Effects

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2261
Author(s):  
Stelios K. Georgantzinos ◽  
Panagiotis A. Antoniou ◽  
Georgios I. Giannopoulos ◽  
Antonios Fatsis ◽  
Stylianos I. Markolefas
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Micromechanical Model ◽  
Laminated Composite ◽  
Theoretical Data ◽  
Composite Plates ◽  
Design Parameters ◽  
Rectangular Plates ◽  
Multiwalled Carbon ◽  
Agglomeration Effects

In the present study, a buckling analysis of laminated composite rectangular plates reinforced with multiwalled carbon nanotube (MWCNT) inclusions is carried out using the finite element method (FEM). The rule of mixtures and the Halpin–Tsai model are employed to calculate the elastic modulus of the nanocomposite matrix. The effects of three critical factors, including random dispersion, waviness, and agglomeration of MWCNTs in the polymer matrix, on the material properties of the nanocomposite are analyzed. Then, the critical buckling loads of the composite plates are numerically determined for different design parameters, such as plate side-to-thickness ratio, elastic modulus ratio, boundary conditions, layup schemes, and fiber orientation angles. The influence of carbon nanotube fillers on the critical buckling load of a nanocomposite rectangular plate, considering the modified Halpin–Tsai micromechanical model, is demonstrated. The results are in good agreement with experimental and other theoretical data available in the open literature.

Hygrothermal Buckling Response of Laminated Composite Plates with Random Material Properties: Micro-Mechanical Model

2011 ◽  
Vol 110-116 ◽  
pp. 113-119 ◽  
Author(s):  
Rajesh Kumar ◽  
Dharamveer Singh
Keyword(s):  
Material Properties ◽  
Plate Theory ◽  
Perturbation Technique ◽  
Micromechanical Model ◽  
Laminated Composite ◽  
Composite Plates ◽  
Second Order Statistics ◽  
Operational Life ◽  
Safety And Reliability ◽  
Random Material Properties

The aim of this paper is to find out the randomness in the material properties on the buckling of laminated composite plate needed for the economy, safety and reliability of the structures and components in their operational life especially for sensitive Aerospace Engineering applications in hygrothermal environments. Micromechanical model has been taken for the analysis .The used methodology is a C0 finite element method based on higher-order shear deformation plate theory for deriving the standard eigenvalue problem. A Taylor series based mean-centered first order perturbation technique is used to find out the second order statistics of the hygrothermal buckling loads under different sets of environmental conditions..The numerical results for deterministic parameters are compared and validated with available literature and random parameters with independent Monte Carlo Simulation. The result shows that the plate is significantly affected by the hygrothermal buckling load.

scholarly journals Manufacturing Aluminum/Multiwalled Carbon Nanotube Composites via Laser Powder Bed Fusion

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3927
Author(s):  
Eo Ryeong Lee ◽  
Se Eun Shin ◽  
Naoki Takata ◽  
Makoto Kobashi ◽  
Masaki Kato
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Energy Density ◽  
Laser Power ◽  
Multiwalled Carbon Nanotube ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Multiwalled Carbon ◽  
Powder Bed ◽  
Scan Speed

This study provides a novel approach to fabricating Al/C composites using laser powder bed fusion (LPBF) for a wide range of structural applications utilizing Al-matrix composites in additive manufacturing. We investigated the effects of LPBF on the fabrication of aluminum/multiwalled carbon nanotube (Al/MWCNT) composites under 25 different conditions, using varying laser power levels and scan speeds. The microstructures and mechanical properties of the specimens, such as elastic modulus and nanohardness, were analyzed, and trends were identified. We observed favorable sintering behavior under laser conditions with low energy density, which verified the suitability of Al/MWCNT composites for a fabrication process using LPBF. The size and number of pores increased in specimens produced under high energy density conditions, suggesting that they are more influenced by laser power than scan speed. Similarly, the elastic modulus of a specimen was also more affected by laser power than scan speed. In contrast, scan speed had a greater influence on the final nanohardness. Depending on the laser power used, we observed a difference in the crystallographic orientation of the specimens by a laser power during LPBF. When energy density is high, texture development of all samples tended to be more pronounced.

Application of an Equivalent Circuit Model for Ionic Polymer-Metal Composite (IPMC) Bending Actuator Loaded With Multiwalled Carbon Nanotube (M-CNT)

2006 ◽  
Vol 309-311 ◽  
pp. 593-596 ◽  
Author(s):  
Deuk Yong Lee ◽  
Kwang Jin Kim ◽  
Seok Heo ◽  
Myung Hyun Lee ◽  
Bae Yeon Kim
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Equivalent Circuit ◽  
Electric Fields ◽  
Electromechanical Coupling ◽  
Equivalent Circuit Model ◽  
Metal Composite ◽  
Multiwalled Carbon ◽  
Equivalent Circuit Analysis ◽  
Bending Actuator

Biomimetic actuators that can produce soft-actuation but large force generation capability are of interest. NafionTM, an effective ionomeric material from DuPont, has been shown to produce large deformation under low electric fields (<10V/mm). In this effort, multi-walled carbon nanotube (M-CNT)/NafionTM nanocomposites were prepared by casting in order to investigate the effect of M-CNT loading in the range of 0 to 7 wt% on electromechanical properties of the MCNT/ NafionTM nanocomposites. The measured elastic modulus and actuation force of the MCNT/ NafionTM nanocomposites are drastically different, showing larger elastic modulus and improved electromechanical coupling, from the one without M-CNT. In this work, we attempted to incorporate an equivalent circuit analysis to address the effect of capacitance and resistance of such M-CNT/NafionTM nanocomposites that would differ from conventional IPMCs.

Thermal Bending of Thick Rectangular Plates of Bimodulus Composite Materials

1980 ◽  
Vol 22 (6) ◽  
pp. 297-304 ◽  
Author(s):  
J. N. Reddy ◽  
C. W. Ber ◽  
Y. S. Hsu ◽  
V. S. Reddy
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Plate Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Normal Strain ◽  
Rectangular Plates ◽  
Fibre Direction ◽  
Thermal Bending ◽  
Good Agreement

Closed-form and finite-element solutions are presented for thermal bending and stretching of laminated composite plates. The material of each layer is assumed to be elastically and thermoelastically orthotropic and bimodular, i.e., having different properties depending upon whether the fibre-direction normal strain is tensile or compressive. The formulations are based on the thermoelastic version of the Whitney-Pagano laminated plate theory, which includes thickness shear deformations. Numerical results are obtained for deflections and neutral-surface positions associated with normal strains in both of the in-plane coordinates. The closed-form and finite-element results are found to be in good agreement.

scholarly journals First Order Shear Deformation Theory access for the stress research of CNT/Polymer Laminated Composite Plates

2019 ◽  
Vol 8 (6) ◽  
pp. 3736-3740
Keyword(s):  
Carbon Nanotube ◽  
Shear Deformation ◽  
Polymer Composite ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Theory Approach ◽  
Laminated Composite Plates ◽  
First Order

In the design of structural elements like shells, beams, and plates the analysis of stresses is one of the primary and most important considerations. The intention of the current research is to perform a study on stress behavior of laminated polymer composite plates reinforced with carbon nanotube(CNT). A theoretical first order shear deformation theory approach is executed on simply supported laminated composite plates subjected to uniformly distributed loads to study the effect of shear deformation on in-plane and transverse stresses. The numerical results are presented for symmetrical, eight layered polymer composite reinforced with Carbon Nanotube to explore the effect of various parameters like stacking sequence, the side-to-thickness ratio on stresses. The effect of carbon nanotube volume fraction and carbon nanotube radius is also investigated on stress distribution of composite plates. This study on stress analysis is conducted on plates principally to observe the structural suitability of nanocomposites.

scholarly journals Thermal Buckling of Laminated Composite Plates Using a Simple Four Variable Plate Theory

2021 ◽  
Vol 27 (9) ◽  
pp. 1-19
Author(s):  
Hussein Tawfeeq Yahea ◽  
Wedad Ibraheem Majeed
Keyword(s):  
Plate Theory ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Thermal Buckling ◽  
Design Parameters ◽  
Laminated Composite Plates ◽  
Buckling Behavior ◽  
Uniform Temperature Field

In this study, the thermal buckling behavior of composite laminate plates cross-ply and angle-ply all edged simply supported subjected to a uniform temperature field is investigated, using a simple trigonometric shear deformation theory. Four unknown variables are involved in the theory, and satisfied the zero traction boundary condition on the surface without using shear correction factors, Hamilton's principle is used to derive equations of  motion depending on a Simple Four Variable Plate Theory for cross-ply and angle-ply, and then solved through Navier's double trigonometric sequence, to obtain critical buckling temperature for laminated composite plates. Effect of changing some design parameters such as, orthotropy ratio (E1/E2), aspect ratio (a/b),  thickness ratio (a/h), thermal expansion coefficient ratio (α2/α1), are investigated, which have the same behavior and good agreement when compared with previously published results with maximum discrepancy (0.5%).

scholarly journals Thermal Buckling Analysis of Laminated Composite plates with General Elastic Boundary Supports

2020 ◽  
Vol 26 (3) ◽  
pp. 1-17
Author(s):  
Mohammed Basheer Alabas ◽  
Wedad Ibrahim Majid
Keyword(s):  
Boundary Condition ◽  
Fourier Series ◽  
Plate Theory ◽  
Ritz Method ◽  
Laminated Composite ◽  
Composite Plates ◽  
Thermal Buckling ◽  
Transverse Displacement ◽  
Rectangular Plates ◽  
Elastic Boundary

In this study, the modified Rayleigh-Ritz method and Fourier series are used to determine the thermal buckling behavior of laminated composite thin plates with a general elastic boundary condition applied to in-plane uniform temperature distribution depending upon classical laminated plate theory(CLPT). A generalized procedure solution is developed for the Rayleigh-Ritz method combined with the synthetic spring technique. The transverse displacement of the orthotropic rectangular plates is not a different term as a new shape expansion of trigonometric series. In this solution approach, the plate transverse deflection and rotation due to bending are developed into principle Fourier series with a sufficient smoothness auxiliary polynomial function, the variable of boundary condition can be easily done by only change the boundary spring stiffness of at the all boundaries of laminated composite plate without achieving any replacement to the solution. The accuracy of the current outcome is verified by comparing with the result obtained from other analytical methods in addition to the finite element method (FEM), so the excellent of this technique is proving during numerical examples.

scholarly journals Free Vibration Analysis of Laminated Composite Plates with General Boundary Elastic Supports Under Initial Thermal Load

2019 ◽  
Vol 15 (4) ◽  
pp. 23-32
Author(s):  
Mohammed B. Hammed ◽  
Widad I. Majeed
Keyword(s):  
Aspect Ratio ◽  
Free Vibration ◽  
Natural Frequency ◽  
Thermal Load ◽  
Ritz Method ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Composite Plates ◽  
Design Parameters ◽  
Laminated Plate

Free vibration behavior was developed under the ratio of critical buckling temperature of laminated composite thin plates with the general elastic boundary condition. The equations of motion were found based on classical laminated plate theory (CLPT) while the solution functions consists of trigonometric function and a continuous function that is added to guarantee the sufficient smoother of the so-named remaining displacement function at the boundaries, in this research, a modified Fourier series were used, a generalized procedure solution was developed using Ritz method combined with the imaginary spring technique. The influences of many design parameters such as angles of layers, aspect ratio, thickness ratio, and ratio of initial in- plane thermal load in addition to different boundary conditions on the natural frequencies of laminated plate is analyzed. In general, the changes of fundamental natural frequency is inversely proportional with the ratio of thermal buckling load, also most parameters aspect ratio effect on the natural frequency about 35 – 40%. The present results were compared with those obtained by other researchers, and show good agreement.

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