scholarly journals Vibration Analysis of Partially Cracked Symmetric Laminated Composite Plates Using Grey-Taguchi

2021 ◽  
Vol 12 (4) ◽  
pp. 4529-4543
Keyword(s):  
Plate Theory ◽  
Weight Ratio ◽  
Laminated Composite ◽  
Composite Plates ◽  
High Strength ◽  
Crack Size ◽  
Width Ratio ◽  
Length Width ◽  
Grey Relation ◽  
Grey Taguchi

Nowadays, the demand for carbon-boron boron-based composites has tremendously increased in the aerospace and automotive industries due to their lightweight and high strength-weight ratio. Hence, it is necessary to study the vibrational behavior of the carbon-boron matrix. The stacking sequences, fiber orientation, crack size, and length-width ratio has all been studied at three levels. A mathematical model has been developed using classical laminated plate theory to evaluate the natural frequency for two boundary conditions; first, all sides were supported (SSSS), second, two adjacent sides clamped, and the other two were simply supported (CCSS). Grey relation analysis has also been applied to optimize the parameters.

scholarly journals The Meshless Element Free Galerkin Method for Buckling Analysis of Simply Supported Laminate Composite Plates

2012 ◽  
Vol 21 (6) ◽  
pp. 096369351202100
Author(s):  
Yeliz Pekbey ◽  
Farshid K. Maleki ◽  
Hasan Yildiz ◽  
Goudarz G. Hesar
Keyword(s):  
Galerkin Method ◽  
Plate Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Width Ratio ◽  
Laminated Composite Plates ◽  
Element Free Galerkin Method ◽  
Simply Supported ◽  
Element Free Galerkin ◽  
Element Free

A meshless element free Galerkin method (EFG) is presented to analyze the buckling of laminated composite plates using the classical (Kirchhoff's) plate theory (CPT) formulation. In the meshless EFG method, the moving least-squares (MLS) technique which does not satisfies the Kroneckar delta feature is used to set up the shape functions. The accuracy and the efficiency of the meshless EFG method are thus demonstrated by the numerical analysis of laminated composite plates with simply supported boundary conditions. Effects of the number of layers, ply orientations, the length-to-width ratio and modulus ratio on the dimensionless buckling loads are investigated. The results obtained by the EFG method are compared with those obtained by the CPT and the finite-element method (FEM). EFG results have good agreements with the analytical solutions. Comparison of results with the CPT as well as the FEM suggests that the meshless element free Galerkin method (EFG) yields an effective solution method for the analysis of laminated composite plates.

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.

Investigation on M-A Constituent in Weld CGHAZ of High-Strength Microalloyed Steel

2008 ◽  
Vol 575-578 ◽  
pp. 690-695 ◽  
Author(s):  
Cui Xin Chen ◽  
Wu Shen Li ◽  
Hui Fen Peng
Keyword(s):  
Thermal Cycle ◽  
Microalloyed Steel ◽  
Influencing Factor ◽  
High Strength ◽  
Cooling Time ◽  
Area Fraction ◽  
Width Ratio ◽  
Maximum Area ◽  
Maximum Value ◽  
Length Width

Thermal simulating technology was used to simulate weld CGHAZ of microalloyed steel with different thermal cycle for the purpose of investigation on morphology of M-A constituent and its influence on toughness. The experimental results showed that in comparison with base metal specimens after thermal cycle have poorer toughness for its larger size, elongated and sharp massive shape and non-uniform distribution. Toughness of specimen value has maximum value with maximum area fraction for cooling time of 7s, and then it will drop whether cooling time is longer or shorter. Moreover, its mean chords of all specimens are all smaller than 0.5μm. Only those with the length larger than 2μm or the length-width ratio exceeding 4, cleavage fracture can occur. So it is concluded that M-A constituent is not the main influencing factor of impairing toughness for steel with different thermal cycle for its smaller mean chord and area fraction.

Analysis of Symmetric Angle-Ply Laminated Composite Skew Plates Using Hybrid Trefftz Finite Element

2019 ◽  
Author(s):  
Subhasankar Dwibedi
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Plate Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Point Load ◽  
Shear Stresses ◽  
Skew Angle ◽  
Distributed Load ◽  
Trefftz Finite Element

Abstract Analysis of symmetric angle-ply skew laminated composite plates has been presented in the study using a newly developed hybrid Trefftz finite element (hTFE). Mindlin’s plate theory has been used to develop the present hTFE. The forms of displacement are assumed such that governing partial differential equations are satisfied a priori inside the element domain. Particular solutions of the governing equations have been ignored and Trefftz functions are derived using the homogenous solutions only. Inter-element continuity has been established by employing another displacement field along the edges of the hTFEs. The transverse shear stresses have been ignored at the top and bottom surfaces of the laminate. The angle of inclination of the width of the plate with the y-axis has been taken as the skew angle and different forms of skew plates are obtained by varying the skew angle. Sinusoidally distributed load (SDL), uniformly distributed load (UDL), and point load (PL) have been subjected to the top surface of the laminate and the non-dimensionalized center point deflection have been evaluated to assess the performance of the present hTFE. The observation from the present study further reinforce the versatility of the hTFE method for analysis of composite structures with complex shapes or geometries.

scholarly journals Geometrical behavior of laminated graphite/epoxy composite using hypermesh

2018 ◽  
Vol 7 (2.20) ◽  
pp. 214
Author(s):  
Ch Siva RamaKrishna ◽  
KV Subba Rao ◽  
Saineelkamal Arji
Keyword(s):  
Residual Stresses ◽  
Epoxy Composite ◽  
Weight Ratio ◽  
Laminated Composite ◽  
High Strength ◽  
Element Analysis ◽  
Aspect Ratios ◽  
Military Applications ◽  
Inherent Strength

The laminated composite material is  made of ply which are specically used in automotive, aerospace and military applications due to less in weight and high strength to weight ratio. The role of structural strength is very important in composites, as the material is weak in inherent strength leads to damage of equipment made with the laminated composite. Hence, an accurate understanding of their structural geometrical behavior for residual stresses is required, such as residual stresses with different aspect ratios. In present work, various aspect ratios of laminated composite and its residual stresses are investigated using finite element analysis. The numerical results showed, on the residual stresses, that the effects the change the residual stresses due change of aspect ratio of laminated Graphite/epoxy composite. 

scholarly journals Damage Characterization of Nano-Interleaved CFRP under Static and Fatigue Loading

Fibers ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 13 ◽  
Author(s):  
Mohamad Fotouhi ◽  
Cristiano Fragassa ◽  
Sakineh Fotouhi ◽  
Hamed Saghafi ◽  
Giangiacomo Minak
Keyword(s):  
Acoustic Emissions ◽  
Weight Ratio ◽  
Laminated Composite ◽  
High Strength ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Limiting Factor ◽  
Delamination Toughness ◽  
Delamination Resistance ◽  
Laminated Composite Materials

The use of high strength-to-weight ratio-laminated fiber-reinforced composites is emerging in engineering sectors such as aerospace, marine and automotive to improve productivity. Nevertheless, delamination between the layers is a limiting factor for the wider application of laminated composites, as it reduces the stiffness and strengths of the structure. Previous studies have proven that ply interface nanofibrous fiber reinforcement has an effective influence on delamination resistance of laminated composite materials. This paper aims to investigate the effect of nanofiber ply interface reinforcement on mode I properties and failure responses when being subjected to static and fatigue loadings. For this purpose, virgin and nanomodified woven laminates were subjected to Double Cantilever Beam (DCB) experiments. Static and fatigue tests were performed in accordance with standards and the Acoustic Emissions (AE) were acquired during these tests. The results showed not only a 130% increase of delamination toughness for nanomodified specimens in the case of static loads, but also a relevant crack growth resistance in the case of fatigue loads. In addition, the AE permitted to relate these improvements to the different failure mechanisms occurring.

Thermoelastic bending analysis of laminated composite plates according to various shear deformation theories

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Atteshamuddin Shamshuddin Sayyad ◽  
Bharati Machhindra Shinde ◽  
Yuwaraj Marotrao Ghugal
Keyword(s):  
Shear Stress ◽  
Shear Deformation ◽  
Transverse Shear ◽  
Virtual Work ◽  
Plate Theory ◽  
Thermal Response ◽  
Laminated Composite ◽  
Composite Plates ◽  
Shear Stresses ◽  
Laminated Composite Plates

AbstractThis study presents the thermoelastic analysis of laminated composite plates subjected to sinusoidal thermal load linearly varying across the thickness. Analytical solutions for thermal displacements and stresses are investigated by using a unified plate theory which includes different functions in terms of thickness coordinate to represent the effect of shear deformation. The theory presented is variationally consistent, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Governing equations of equilibrium and associated boundary conditions of the theory are obtained using the principle of virtual work. The Navier solution for simply supported laminated composite plates has been developed. Numerical results are presented to demonstrate the thermal response of the laminated composite plates.

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