Tailoring the Fundamental Frequency of Laminated Composite Panels Using Material Properties

2014 ◽  
Vol 709 ◽  
pp. 157-161
Author(s):  
Li Guo Zhang ◽  
Kang Yang ◽  
Wei Ping Zhao ◽  
Song Xiang
Keyword(s):  
Fundamental Frequency ◽  
Material Properties ◽  
Present Method ◽  
Optimization Problem ◽  
Laminated Composite ◽  
Composite Panels ◽  
Fundamental Frequencies ◽  
Laminated Panels ◽  
Frequency Optimization ◽  
Optimal Material

Optimization of material properties is performed to maximize the fundamental frequency of the laminated composite panels by means of the genetic algorithm. The global radial basis function collocation method is used to calculate the fundamental frequency of clamped laminated composite panels. In this paper, the objective function of optimization problem is the maximum fundamental frequency; optimization variables are material properties of laminated panels. The results for the optimal material properties and the maximum fundamental frequencies of the 2-layer plates are presented to verify the validity of present method.

Layer Thickness Optimization of Laminated Composite Plates to Maximize the First-Order Natural Frequency

2014 ◽  
Vol 709 ◽  
pp. 139-143
Author(s):  
Li Guo Zhang ◽  
Kang Yang ◽  
Wei Ping Zhao ◽  
Song Xiang
Keyword(s):  
Layer Thickness ◽  
Natural Frequency ◽  
Present Method ◽  
Optimization Problem ◽  
Laminated Composite ◽  
Composite Plates ◽  
Thickness Optimization ◽  
Laminated Composite Plates ◽  
First Order ◽  
Frequency Optimization

Layer thickness optimization is performed to maximize the first-order natural frequency of clamped laminated composite plates using the genetic algorithm and meshless global radial basis function collocation method. The objective function of optimization problem is the maximum first-order natural frequency; optimization variables are layer thickness. The optimal layer thickness and the maximum first-order natural frequency of the 2-layer plates are presented to demonstrate the accuracy of present method.

On the Prediction of Extremal Material Properties and Optimal Material Distribution for Multiple Loading Conditions

1994 ◽  
Author(s):  
Martin P. Bendsøe ◽  
Alejandro R. Díaz ◽  
Robert Lipton ◽  
John E. Taylor
Keyword(s):  
Material Properties ◽  
Optimization Problem ◽  
Simultaneous Optimization ◽  
Elastic Continuum ◽  
Linear Elastic ◽  
Recent Developments ◽  
Multiple Loading ◽  
Optimal Material ◽  
The Cost ◽  
Structural Optimization Problem

Abstract This paper describes some recent developments that treats the simultaneous optimization of material and structure for minimum compliance. The basic idea is to represent the material properties for a linear elastic continuum in the most general form possible namely as the unrestricted set of elements of positive semi-definite constitutive tensors. The cost of resource is measured through certain invariants of the tensors, here the 2-norm or the trace of the tensors. The advantage of this general formulation is that analytical forms for the optimized material properties can be derived and that effective methods for computational solution can be devised for the resulting reduced structural optimization problem.

scholarly journals Finite element studies on free vibration of laminated composite cylindrical skew panels

2014 ◽  
Vol 19 (1) ◽  
pp. 165-180
Author(s):  
C.V. Srinivasa ◽  
Y.J. Suresh ◽  
W.P. Prema Kumar
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Fundamental Frequency ◽  
Composite Laminates ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Skew Angle ◽  
Fundamental Frequencies ◽  
Number Of Layers ◽  
Fiber Orientation Angle

Abstract This paper presents the finite element studies on free vibration of isotropic and laminated composite cylindrical skew panels. The analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. The effects of the panel angle, skew angle, aspect ratio and length-to-thickness-ratio on fundamental frequency of isotropic cylindrical skew panels are studied. The effects of additional parameters such as the fiber orientation angle, numbers of layers and stacking sequence on the fundamental frequency of antisymmetric composite laminates are also studied. It is found that the CQUAD8 element yields better results than the CQUAD4 element in the validation and convergence studies. The CQUAD8 element is employed for the remaining part of the studies. The fundamental frequencies are found to increase with the panel angle and skew angle. When the number of layers in the laminate is large, the variation of the fundamental frequency with the number of layers is not appreciable. The boundary conditions are found to have a significant influence on the fundamental frequency

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.

An Analytical Model to Predict Optimal Material Properties in the Context of Optimal Structural Design

1994 ◽  
Vol 61 (4) ◽  
pp. 930-937 ◽  
Author(s):  
M. P. Bendsoe ◽  
J. M. Guedes ◽  
R. B. Haber ◽  
P. Pedersen ◽  
J. E. Taylor
Keyword(s):  
Material Properties ◽  
Structural Design ◽  
Optimization Problem ◽  
Existence Of Solutions ◽  
Simultaneous Optimization ◽  
Elastic Continuum ◽  
Linear Elastic ◽  
Optimal Material ◽  
Structural Optimization Problem ◽  
Principal Strains

This paper deals with the simultaneous optimization of material and structure for minimum compliance. Material properties are represented in the most general form possible for a (locally) linear elastic continuum, namely the unrestricted set of elements of positive semi-definite constitutive tensors and cost measures based on certain invariants of the tensors. Analytical forms are derived for the optimized material properties. These results, which apply in general, indicate that the optimized material is orthotropic with the directions of orthotropy following the directions of principal strains. The analysis for optimization of the material leads to a reduced structural optimization problem, for which the existence of solutions can be shown and for which effective methods for computational solution can be devised.

scholarly journals A new proof of the dual optimization problem and its application to the optimal material distribution of SiC/graphene composite

2020 ◽  
Vol 1 (1) ◽  
pp. 187-191
Author(s):  
Ji-Huan He ◽  
Keyword(s):  
Material Properties ◽  
Optimization Problem ◽  
Dual Problem ◽  
Direct Proof ◽  
Duality Gap ◽  
Material Distribution ◽  
Dual Problems ◽  
Graphene Composite ◽  
Stationary Conditions ◽  
Optimal Material

This paper presents a simple and direct proof of the dual optimization problem. The stationary conditions of the original and the dual problems are exactly equivalent, and the duality gap can be completely eliminated in the dual problem, where the maximal or minimal value is solved together with the stationary conditions of the dual problem and the original constraints. As an illustration, optimization of SiC/graphene composite is addressed with an objective of maximizing certain material properties under the constraint of a given strength.

A Tape Striation Counting Method for Determining Fundamental Frequency

1979 ◽  
Vol 10 (4) ◽  
pp. 246-248 ◽  
Author(s):  
Peter B. Mueller ◽  
Marla Adams ◽  
Jean Baehr-Rouse ◽  
Debbie Boos
Keyword(s):  
Fundamental Frequency ◽  
Counting Method ◽  
Male And Female ◽  
Fundamental Frequencies ◽  
Counting Procedure ◽  
Female Subjects

Mean fundamental frequencies of male and female subjects obtained with FLORIDA I and a tape striation counting procedure were compared. The fundamental frequencies obtained with these two methods were similar and it appears that the tape striation counting procedure is a viable, simple, and inexpensive alternative to more costly and complicated procedures and instrumentation.

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