Stochastic aeroelastic analysis of laminated composite plate with variable fiber spacing

2021 ◽  
pp. 002199832110408
Author(s):  
Narayan Sharma ◽  
Prasant Kumar Swain ◽  
Dipak Kumar Maiti ◽  
Bhrigu Nath Singh
Keyword(s):  
Perturbation Technique ◽  
Laminated Composite ◽  
Distribution Patterns ◽  
Laminated Plates ◽  
Fiber Distribution ◽  
Various Boundary Conditions ◽  
Aeroelastic Analysis ◽  
Fiber Spacing ◽  
Reliability Method ◽  
Parametric Studies

In this paper, the dynamic and aeroelastic analysis of variable fiber spacing composite (VFSC) laminated plates are carried out. The effects and benefits of changing the fiber distribution pattern on natural frequency and mode shape are explored taking various boundary conditions. Taking cantilever boundary condition flutter characteristics of VFSC plate with different fiber distribution patterns are compared. Further stochasticity of flutter velocity due to randomness in material properties that could arise due to complex manufacturing and fabrication process of VFSC laminates is investigated. The perturbation technique is implemented to perform the stochastic as well as reliability analysis. Various parametric studies are conducted to check the accuracy and efficiency of perturbation technique, by comparing the results with that of Monte Carlo simulation and the first-order reliability method.

scholarly journals Analysis of buckling phenomenon of rectangular laminated plates with a hole under different boundary conditions

2018 ◽  
Vol 149 ◽  
pp. 02013
Author(s):  
Ahmed El Bouhmidi ◽  
Mohamed Rougui
Keyword(s):  
Boundary Conditions ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Laminated Plates ◽  
Element Analysis ◽  
Different Boundary Conditions ◽  
First Order ◽  
Various Boundary Conditions ◽  
Buckling Behavior ◽  
Ply Orientation

In this research, buckling behavior of perforated rectangular plate of symmetric and anti-symmetric laminated composite is investigated based on Finite element analysis. The presence of hole may cause redistribution of stresses in plates with reduction of stability. The aim of the current paper is to find critical buckling load by using the (FSDT) first-order shear deformation theory in concomitance with the variational energy method. The load depends on many factors like as diameter of circular hole, different boundary conditions, lay-up sequences, length/thickness ratio and angle of ply orientation. The result is shown in graphical forms for various boundary conditions.

Stochastic Finite Element Buckling Analysis of Laminated Plates With Circular Cutout Under Uniaxial Compression

2006 ◽  
Vol 74 (4) ◽  
pp. 798-809 ◽  
Author(s):  
A. K. Onkar ◽  
C. S. Upadhyay ◽  
D. Yadav
Keyword(s):  
Material Properties ◽  
Perturbation Technique ◽  
Compressive Loading ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Analysis ◽  
Laminated Plates ◽  
Buckling Strength ◽  
The Mean ◽  
Random Material Properties

A generalized stochastic buckling analysis of laminated composite plates, with and without centrally located circular cutouts having random material properties, is presented under uniaxial compressive loading. In this analysis, the layerwise plate model is used to solve both prebuckling and buckling problems. The stochastic analysis is done based on mean centered first-order perturbation technique. The mean buckling strength of composite plates is validated with results available in the literature. It has been observed that the present analysis can predict buckling load accurately even for plates with large cutouts. Micromechanics based approach is used to study the effect of variation in microlevel constituents on the effective macrolevel properties like elastic moduli. Consequently, the effect of uncertainty in these material properties on the buckling strength of the laminated plates is studied. Parametric studies are carried out to see the effect of hole size, layups, and boundary conditions on the mean and variance of plate buckling strength.

Reliability Analysis of FRP Laminated Plates With Initial Imperfection

2002 ◽  
Author(s):  
Jianqiao Chen ◽  
Xiangyang Wang ◽  
Cheng Luo
Keyword(s):  
Failure Probability ◽  
Progressive Failure ◽  
Laminated Composite ◽  
Initial Imperfection ◽  
Strength Criterion ◽  
Laminated Plates ◽  
System Failure ◽  
Strength Parameters ◽  
Compression Load ◽  
Reliability Method

In this paper, a probabilistic progressive failure analysis method is applied to estimating the reliability of a simply supported laminated composite plate with an initial imperfection under bi-axial compression load. The initial imperfection and the strength parameters are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method (FORM) together with the Tsai-Wu strength criterion and Tan criterion. Current stresses in the laminated structure are calculated by classical lamination theory with the stiffness being modified based on the last step ply failure. Probabilistieally dominant ply-level failure sequences leading to overall system failure are identified by branch and bound method. The system failure probability is estimated through the union of significant failure sequences. A numerical example is presented to demonstrate the methodology proposed. Parameter studies show that the deviation of the initial imperfection and strength parameters largely influence the system reliability.

THERMAL BUCKLING OF LAMINATED COMPOSITE PLATES WITH RANDOM GEOMETRIC AND MATERIAL PROPERTIES

2009 ◽  
Vol 09 (02) ◽  
pp. 187-211 ◽  
Author(s):  
VIPIN K. VERMA ◽  
B. N. SINGH
Keyword(s):  
Composite Plate ◽  
Perturbation Technique ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Composite Plates ◽  
Geometric Properties ◽  
Various Boundary Conditions ◽  
The Mean ◽  
Standard Derivation

In this paper, a C o finite element has been employed for deriving an eigenvalue problem using higher order shear deformation theory. The uncertain material and geometric properties are modeled as basic random variables. A mean-centered first order perturbation technique is used to find the mean and standard derivation of the buckling temperature of laminated composite plates — subjected to a uniform temperature rise — with random material and geometric properties. The effects of the modulus ratio, fiber orientation, length-to-thickness ratio, aspect ratio and various boundary conditions on the critical temperature are examined. It is found that small variations in material and geometric properties of the composite plate significantly affect the buckling temperature of the laminated composite plate. The results have been validated with independent Monte Carlo simulation and those available in the literature.

scholarly journals Interfacial Morphology and Bonding Mechanism of Explosive Weld Joints

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Tingting Zhang ◽  
Wenxian Wang ◽  
Zhifeng Yan ◽  
Jie Zhang
Keyword(s):  
Laminated Composite ◽  
Base Plate ◽  
Sine Wave ◽  
Laminated Plates ◽  
Bonding Interface ◽  
Interfacial Structure ◽  
Bonding Mechanism ◽  
Critical Material ◽  
Interfacial Morphology ◽  
Az31b Alloy

AbstractInterfacial structure greatly affects the mechanical properties of laminated plates. However, the critical material properties that impact the interfacial morphology, appearance, and associated bonding mechanism of explosive welded plates are still unknown. In this paper, the same base plate (AZ31B alloy) and different flyer metals (aluminum alloy, copper, and stainless steel) were used to investigate interfacial morphology and structure. SEM and TEM results showed that typical sine wave, wave-like, and half-wave-like interfaces were found at the bonding interfaces of Al/Mg, Cu/Mg and SS/Mg clad plates, respectively. The different interfacial morphologies were mainly due to the differences in hardness and yield strength between the flyer and base metals. The results of the microstructural distribution at the bonding interface indicated metallurgical bonding, instead of the commonly believed solid-state bonding, in the explosive welded clad plate. In addition, the shear strength of the bonding interface of the explosive welded Al/Mg, Cu/Mg and SS/Mg clad plates can reach up to 201.2 MPa, 147.8 MPa, and 128.4 MPa, respectively. The proposed research provides the design basis for laminated composite metal plates fabrication by explosive welding technology.

Application of Generalized Differential Quadrature Method to the Bending of Thick Laminated Plates with Various Boundary Conditions

2006 ◽  
Vol 5-6 ◽  
pp. 407-414 ◽  
Author(s):  
Mohammad Mohammadi Aghdam ◽  
M.R.N. Farahani ◽  
M. Dashty ◽  
S.M. Rezaei Niya
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Simple Procedure ◽  
Shear Deformation Theory ◽  
Laminated Plates ◽  
Differential Quadrature ◽  
Governing Equations ◽  
First Order ◽  
Various Boundary Conditions ◽  
Generalized Differential

Bending analysis of thick laminated rectangular plates with various boundary conditions is presented using Generalized Differential Quadrature (GDQ) method. Based on the Reissner first order shear deformation theory, the governing equations include a system of eight first order partial differential equations in terms of unknown displacements, forces and moments. Presence of all plate variables in the governing equations provide a simple procedure to satisfy different boundary condition during application of GDQ method to obtain accurate results with relatively small number of grid points even for plates with free edges .Illustrative examples including various combinations of clamped, simply supported and free boundary condition are given to demonstrate the accuracy and convergence of the presented GDQ technique. Results are compared with other analytical and finite element predictions and show reasonably good agreement.

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.

Determination of Vibration Source Locations in Laminated Composite Plates Using Lamb Wave Analysis

2010 ◽  
Vol 123-125 ◽  
pp. 899-902
Author(s):  
Chao Du ◽  
Qing Qing Ni ◽  
Toshiaki Natsuki
Keyword(s):  
Lamb Wave ◽  
Guided Waves ◽  
Lamb Waves ◽  
Laminated Composite ◽  
Composite Plates ◽  
Wave Dispersion ◽  
Laminated Plates ◽  
Vibration Source ◽  
Arrival Times ◽  
Wave Velocities

Signals propagate on plate-like structures as ultrasonic guided waves, and analysis of Lamb waves has been widely used for on-line monitoring. In this study, the wave velocities of symmetric and anti-symmetric modes in various directions of propagation were investigated. Since the wave velocities of these two modes are different, it is possible to compute the difference in their arrival times when these waves propagated the distance from the vibration source to sensor. This paper presents an evaluation formulation of wave velocity and describes a generalized algorithm for locating a vibration source on a thin, laminated plate. With the different velocities of two modes based on Lamb wave dispersion, the method uses two sensors to locate the source on a semi-infinite interval of a plate. The experimental procedure supporting this method employs pencil lead breaks to simulate vibration sources on quasi-isotropic and unidirectional laminated plates. The transient signals generated in this way are transformed using a wavelet transform. The vibration source locations are then detected by utilizing the distinct wave velocities and arrival times of the symmetric and anti-symmetric wave modes. The method is an effective technique for identifying impact locations on plate-like structures.

Thermo-Mechanical Buckling Analysis of Functionally Graded Skew Laminated Plates with Initial Geometric Imperfections

2018 ◽  
Vol 10 (02) ◽  
pp. 1850014 ◽  
Author(s):  
Sanjay Singh Tomar ◽  
Mohammad Talha
Keyword(s):  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Laminated Plates ◽  
Geometric Imperfections ◽  
Efficiency And Effectiveness ◽  
Governing Differential Equation ◽  
Parametric Studies ◽  
Mechanical Buckling ◽  
Initial Geometric Imperfections ◽  
Continuous Displacement

The aim of the present study is to investigate thermo-mechanical buckling response of skew functionally graded laminated plates (FGLP) with initial geometric imperfections. The formulation has been performed using Reddy’s higher order shear deformation theory (HSDT) with the [Formula: see text] continuous displacement field. A nine-noded isoparametric element has been employed to discretize the domain of the plate. Variational principle has been used to derive the governing differential equation of the problem. Several examples with various comparison and parametric studies have been shown to prove the efficiency and effectiveness of the present formulation. The numerical results have been highlighted with different system parameters and boundary conditions.

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