Maximizing Buckling Strength of Perforated Composite Laminates by Optimizing Fiber Orientation Using Genetic Algorithm

2006 ◽  
Author(s):  
H. K. Cho ◽  
R. E. Rowlands
Keyword(s):  
Genetic Algorithm ◽  
Fiber Orientation ◽  
Composite Laminates ◽  
Shell Theory ◽  
Layered Composite ◽  
Laminated Plates ◽  
Genetic Optimization ◽  
Subspace Iteration ◽  
Plate Geometry ◽  
Genetic Optimization Algorithm

This paper demonstrates ability to significantly increase buckling loads of perforated composite laminated plates by synergizing FEM and a genetic optimization algorithm (GA). Plate geometry is discretized into specially-developed 3D degenerated eight-node shell isoparametric layered composite elements. General shell theory, involving incremental nonlinear finite element equilibrium equation, is employed. Fiber orientation within individual plies of each element is controlled independently by the genetic algorithm. Eigen buckling analysis is performed using the subspace iteration method. Available results demonstrate the approach is superior to more conventional methodologies such as modifying ply thickness or the stacking sequence of individual rectilinear plies having common fiber orientation through the plate.

Fiber Orientation Angles Optimization for Maximum Fundamental Frequency of Laminated Composite Plates by the Genetic Algorithm and Meshless Method

2014 ◽  
Vol 709 ◽  
pp. 130-134
Author(s):  
Feng Wang ◽  
Wei Ping Zhao ◽  
Song Xiang
Keyword(s):  
Genetic Algorithm ◽  
Fundamental Frequency ◽  
Fiber Orientation ◽  
Meshless Method ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Laminated Composite Plates ◽  
Fundamental Frequencies ◽  
Design Variables

Fiber orientation angles optimization is carried out for maximum fundamental frequency of clamped laminated composite plates using the genetic algorithm. The meshless method is utilized to calculate the fundamental frequency of clamped laminated composite plates. In the present paper, the maximum fundamental frequency is an objective function; design variables are a set of fiber orientation angles in the layers. The examples of square laminated plates are considered. The results for the optimal fiber orientation angles and the maximum fundamental frequencies of the 2-layer plates are presented.

scholarly journals A Genetic Optimization Algorithm Based on Adaptive Dimensionality Reduction

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Tai Kuang ◽  
Zhongyi Hu ◽  
Minghai Xu
Keyword(s):  
Genetic Algorithm ◽  
Dimensionality Reduction ◽  
Optimization Algorithm ◽  
Simulated Annealing Algorithm ◽  
Optimization Problems ◽  
High Dimensional ◽  
Adaptive Genetic Algorithm ◽  
Genetic Optimization ◽  
Number Of Zeros ◽  
Genetic Optimization Algorithm

With the rise of big data in cloud computing, many optimization problems have gradually developed into high-dimensional large-scale optimization problems. In order to address the problem of dimensionality in optimization for genetic algorithms, an adaptive dimensionality reduction genetic optimization algorithm (ADRGA) is proposed. An adaptive vector angle factor is introduced in the algorithm. When the angle of an individual’s adjacent dimension is less than the angle factor, the value of the smaller dimension is marked as 0. Then, the angle between each individual dimension is calculated separately, and the number of zeros in the population is updated. When the number of zeros of all individuals in a population exceeds a given constant in a certain dimension, the dimension is considered to have no more information and deleted. Eight high-dimensional test functions are used to verify the proposed adaptive dimensionality reduction genetic optimization algorithm. The experimental results show that the convergence, accuracy, and speed of the proposed algorithm are better than those of the standard genetic algorithm (GA), the hybrid genetic and simulated annealing algorithm (HGSA), and the adaptive genetic algorithm (AGA).

Physical Ultrasonics of Composites

2011 ◽  
Author(s):  
Dale Chimenti ◽  
Stanislav Rokhlin ◽  
Peter Nagy
Keyword(s):  
Composite Laminates ◽  
Stiffness Matrix ◽  
Composite Plates ◽  
Anisotropic Media ◽  
Anisotropic Materials ◽  
Ultrasonic Waves ◽  
Laminated Plates ◽  
Structure Characteristic ◽  
Major Advance

Physical Ultrasonics of Composites is a rigorous introduction to the characterization of composite materials by means of ultrasonic waves. Composites are treated here not simply as uniform media, but as inhomogeneous layered anisotropic media with internal structure characteristic of composite laminates. The objective here is to concentrate on exposing the singular behavior of ultrasonic waves as they interact with layered, anisotropic materials, materials which incorporate those structural elements typical of composite laminates. This book provides a synergistic description of both modeling and experimental methods in addressing wave propagation phenomena and composite property measurements. After a brief review of basic composite mechanics, a thorough treatment of ultrasonics in anisotropic media is presented, along with composite characterization methods. The interaction of ultrasonic waves at interfaces of anisotropic materials is discussed, as are guided waves in composite plates and rods. Waves in layered media are developed from the standpoint of the "Stiffness Matrix", a major advance over the conventional, potentially unstable Transfer Matrix approach. Laminated plates are treated both with the stiffness matrix and using Floquet analysis. The important influence on the received electronic signals in ultrasonic materials characterization from transducer geometry and placement are carefully exposed in a dedicated chapter. Ultrasonic wave interactions are especially susceptible to such influences because ultrasonic transducers are seldom more than a dozen or so wavelengths in diameter. The book ends with a chapter devoted to the emerging field of air-coupled ultrasonics. This new technology has come of age with the development of purpose-built transducers and electronics and is finding ever wider applications, particularly in the characterization of composite laminates.

scholarly journals Advanced SIMION Techniques: Boundary Matching and Genetic Optimization

2015 ◽  
Vol 21 (S4) ◽  
pp. 218-223 ◽  
Author(s):  
D. Dowsett
Keyword(s):  
Genetic Algorithm ◽  
Real World ◽  
Great Accuracy ◽  
Genetic Optimization ◽  
Real World Applications ◽  
Boundary Matching

AbstractTwo techniques for use with SIMION [1] are presented, boundary matching and genetic optimization. The first allows systems which were previously difficult or impossible to simulate in SIMION to be simulated with great accuracy. The second allows any system to be rapidly and robustly optimized using a parallelized genetic algorithm. Each method will be described along with examples of real world applications.

THE EFFECT OF LAMINATION SCHEME AND ANGLE VARIATIONS TO THE DISPLACEMENTS AND FAILURE BEHAVIOUR OF COMPOSITE LAMINATE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Azizul Hakim Samsudin ◽  
Jamaluddin Mahmud
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Finite Element Modelling ◽  
Composite Laminate ◽  
Maximum Stress ◽  
Failure Load ◽  
Failure Criteria ◽  
Stress Theory ◽  
Failure Behaviour ◽  
Failure Index

This paper aims to investigate the effect of lamination scheme and angle variations to the displacements and failure behaviour of composite laminate. Finite element modelling and analysis of symmetric, anti-symmetric and angle-ply Graphite/ Epoxy laminate with various angles of fiber orientation subjected to uniaxial tension are performed. Maximum Stress Theory and Tsai-Wu Failure Criteria are employed to determine the failure load (failure index = 1). Prior to that, convergence analysis and numerical validation are carried out. Displacements and failure behaviour of the composite laminates (symmetric, anti-symmetric and angle ply) are analysed. The failure curves (FPF and LPF) for both theories (Maximum Stress Theory and Tsai-Wu) are plotted and found to be very close to each other. Therefore, it can be concluded that the current study is useful and significant to the displacements and failure behaviour of composite laminate.

Experimental Investigation of Impacted and Non-Impacted Composite Laminates under Compressive Loading

2011 ◽  
Vol 284-286 ◽  
pp. 607-610
Author(s):  
Jiang Tao Ruan ◽  
Min Shen ◽  
Jing Wei Tong ◽  
Shi Bin Wang ◽  
Francesco Aymerich ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Compressive Loading ◽  
Laminated Plates ◽  
Low Velocity Impact ◽  
Compressive Deformation ◽  
Electronic Speckle Pattern Interferometry ◽  
Low Velocity ◽  
The Impact

In this paper, the deformation measurements of impacted and non-impacted composite laminates under compressive loading are taken. [03/903]S orientated cross-ply laminated plates with impact delamination and without delamination are tested using an anti-buckling testing device in compression experiment. The delamination is induced by low-velocity impact test at the impact energy level of 3.105J. For both impacted and non-impacted specimens, the compressive deformation is measured by a carrier electronic speckle pattern interferometry (CESPI) optical measurement technique. It is found that the deformation behavior of the two specimens presents a mixed deformation mode. However, the delamination has significant effect on the compressive deformation of composite laminates.

scholarly journals Research on Fan Operation Evaluation and Error State Judgment Relying on Improved Neural Network and Intelligent Computing

2021 ◽  
Vol 2083 (4) ◽  
pp. 042005
Author(s):  
Xueyi Liu ◽  
Junhao Dong ◽  
Guangyu Tu
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Fault Diagnosis ◽  
Wind Turbine ◽  
Performance Prediction ◽  
Optimization Method ◽  
Aerodynamic Performance ◽  
Evaluation Index ◽  
Genetic Optimization ◽  
Quantum Genetic Algorithm

Abstract Fan, as the most commonly used mechanical equipment, is widely used. In order to solve the problem of fan bearing fault diagnosis, this paper analyzes the main factors affecting fan spindle speed and power generation in operation. The input and output parameters of the performance prediction model are determined. The performance prediction model of wind turbine is established by using generalized regression neural network, and the smoothing factor of GRNN is optimized by comparing the prediction accuracy of the model. Based on this model, the sliding data window method is used to calculate the residual evaluation index of wind turbine speed and power in real time. When the evaluation index continuously exceeds the pre-set threshold, the abnormal state of wind turbine can be judged. In order to obtain wind turbine blades with better aerodynamic performance, a blade aerodynamic performance optimization method based on quantum heredity is proposed. The B é zier curve control point is used as the design variable to represent the continuous chord length and torsion angle distribution of the blade, the blade shape optimization model aiming at the maximum power is established, and the quantum genetic algorithm is used to optimize the chord length and torsion angle of the blade under different constraints. The optimization results of quantum genetic algorithm and classical genetic algorithm are compared and analyzed. Under the same parameters and boundary conditions, the proposed blade aerodynamic optimization method based on quantum genetic optimization is better than the classical genetic optimization method, and can obtain better blade aerodynamic shape and higher wind energy capture efficiency. This method makes up for the shortcomings of traditional fault diagnosis methods, improves the recognition rate of fault types and the accuracy of fault diagnosis, and the diagnosis effect is good.

Effect of Fiber Orientation on the Critical Buckling Load of Symmetric Composite Laminated Plates

2012 ◽  
Vol 629 ◽  
pp. 95-99 ◽  
Author(s):  
N. Hamani ◽  
D. Ouinas ◽  
N. Taghezout ◽  
M. Sahnoun ◽  
J. Viña
Keyword(s):  
Fiber Orientation ◽  
Composite Plates ◽  
Laminated Plates ◽  
Buckling Load ◽  
The Finite Element Method ◽  
Notch Radius ◽  
Critical Buckling Load ◽  
Buckling Strength ◽  
Degree Of Anisotropy ◽  
Circular Notch

In this study, a buckling analysis is performed on rectangular composite plates with single and double circular notch using the finite element method. Laminated plates of carbon/bismaleimde (IM7/5250-4) are ordered symmetrically as follows [(θ/-θ)2]S. The buckling strength of symmetric laminated plates subjected to uniaxial compression is highlighted as a function of the fibers orientations. The results show that whatever the notch radius, the buckling load is almost stable. Increasing the degree of anisotropy significantly improves critical buckling load.

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