scholarly journals Optimization of Laminated Composite Plates for Maximum Biaxial Buckling Load

Author(s):  
Pham Dinh Nguyen ◽  
Quang-Viet Vu ◽  
George Papazafeiropoulos ◽  
Hoang Thi Thiem ◽  
Pham Minh Vuong ◽  
...  

This paper proposes an optimization procedure for maximization of the biaxial buckling load of laminated composite plates using the gradient-based interior-point optimization algorithm. The fiber orientation angle and the thickness of each lamina are considered as continuous design variables of the problem. The effect of the number of layers, fiber orientation angles, thickness and length to thickness ratios on the buckling load of the laminated composite plates under biaxial compression is investigated. The effectiveness of the optimization procedure in this study is compared with previous works.

2014 ◽  
Vol 709 ◽  
pp. 144-147
Author(s):  
Ying Tao Chen ◽  
Song Xiang ◽  
Wei Ping Zhao

Optimization of fiber orientation angle is studied to minimize the deflection of the laminated composite plates by the genetic algorithm. The objective function of optimization problem is the minimum deflection of laminated composite plates under the external load; optimization parameters are fiber orientation angle of laminated composite plates. The results for the optimal fiber orientation angle and the minimum deflection of the 4-layer plates are presented to demonstrate the validity of present method.


2014 ◽  
Vol 709 ◽  
pp. 135-138
Author(s):  
Ying Tao Chen ◽  
Song Xiang ◽  
Wei Ping Zhao

The genetic algorithm is used to minimize the stress of the laminated composite plates by optimizing the fiber orientation angle. The objective function of optimization problem is the minimum stress in center of laminated composite plates under the external load; optimization variables are fiber orientation angle. The results for the optimal fiber orientation angle and the minimum stress of the 2-layer plates and 3-layer plates are presented.


2007 ◽  
Vol 334-335 ◽  
pp. 89-92 ◽  
Author(s):  
Shinya Honda ◽  
Yoshihiro Narita ◽  
Katsuhiko Sasaki

Structural plate elements in composite structures are typically fabricated by stacking orthotropic layers, each of which is composed of reinforcing fibers and matrix materials. In this work, three optimum design approaches are compared to clarify the advantages and disadvantages for optimizing the buckling performance of laminated composite plates. The first approach is developed recently by the authors, where the buckling load is maximized with respect to the lamination parameters by a gradient method and then the optimum lay-up design is determined by minimizing the errors between the optimum parameters and parameters for all possible discrete lay-ups. The second approach is the layerwise optimization (LO) approach where the fiber orientation angle in each layer is optimized step-by-step by repeating one dimensional search. The third one is a direct application of a simple genetic algorithm (SGA). In numerical examples, three sets of results are compared to discuss on the methodology for buckling optimization.


2012 ◽  
Vol 19 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Ahmet Erkliğ ◽  
Eyüp Yeter

AbstractCutouts such as circular, rectangular, square, elliptical, and triangular shapes are generally used in composite plates as access ports for mechanical and electrical systems, for damage inspection, to serve as doors and windows, and sometimes to reduce the overall weight of the structure. This paper addresses the effects of different cutouts on the buckling behavior of plates made of polymer matrix composites. To study the effects of cutouts on buckling, loaded edges are taken as fixed and unloaded edges are taken as free. Finite element analysis is also performed to predict the effects of different geometrical cutouts, orientations, and position of cutouts on the buckling behavior. The results show that fiber orientation angle and cutout sizes are the most important parameters on the buckling loads. For all types of cutouts the buckling loads decrease dramatically by increasing the fiber orientation angle. It is observed that minimum buckling load is reached when 45° fiber angle is used, and after this angle critical buckling load begins to increase. Also, it is concluded that while fiber orientation angle is 0°, elliptical cutout has the highest buckling load and while fiber orientation angle is 45°, circular cutout has the highest buckling load.


2014 ◽  
Vol 709 ◽  
pp. 130-134
Author(s):  
Feng Wang ◽  
Wei Ping Zhao ◽  
Song Xiang

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.


2014 ◽  
Vol 21 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Chikkol Venkateshappa Srinivasa ◽  
Yalaburgi Jayadevappa Suresh ◽  
Wooday Puttiah Prema Kumar

AbstractThe present paper presents the finite element studies made on critical buckling load of isotropic and laminated composite cylindrical skew panels. Analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. It is found that the CQUAD8 element yields better results compared to the CQUAD4 element in terms of accuracy and convergence. Using the CQUAD8 element, the effects of the panel angle, skew angle, aspect ratio, and length-to-thickness ratio on the critical buckling load of isotropic cylindrical skew panels have been studied. The effects of additional parameters such as fiber orientation angle, numbers of layers (NL), and stacking sequence on the critical buckling load of laminated composite cylindrical skew panels have also been studied. The critical buckling loads are found to increase with the increase in panel angle and skew angle. When the NL in the laminate is large, the variation of the critical buckling load with the NL is not appreciable. The boundary conditions are found to have significant influence on the critical buckling load.


Author(s):  
S.P. Joshi ◽  
N.G.R. Iyengar

The study is carried out for the optimum design of laminated fiber reinforced composite plates, subjected to multiple in-plane loadings. Angle-ply laminates with orthotropic laminae are considered. Thickness of plies and corresponding fiber orientations are incorporated as design variables. The constrained optimization problem is transformed into a series of unconstrained optimization problems, using an interior penalty function approach. The results have been obtained for different aspect ratios and uniform biaxial in-plane loading ratios. This study shows that the fiber orientations of the plies near mid-plane have little effect on the optimum design. There exists a particular fiber orientation angle for the over all thickness of laminate, which results in the optimum design for a plate of a given aspect ratio under a given set of loadings.


2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
Emin Ergun

The aim of this study is to investigate, experimentally and numerically, the change of critical buckling load in composite plates with different ply numbers, orientation angles, stacking sequences and boundary conditions as a function of temperature. Buckling specimens have been removed from the composite plate with glass-fibre reinforcement at [0°]i and [45°]i (i= number of ply). First, the mechanical properties of the composite material were determined at different temperatures, and after that, buckling experiments were done for those temperatures. Then, numerical solutions were obtained by modelling the specimens used in the experiment in the Ansys10 finite elements package software. The experimental and numerical results are in very good agreement with each other. It was found that the values of the buckling load at [0°] on the composite plates are higher than those of other angles. Besides, symmetrical and anti-symmetrical conditions were examined to see the effect of the stacking sequence on buckling and only numerical solutions were obtained. It is seen that the buckling load reaches the highest value when it is symmetrical in the cross-ply stacking sequence and it is anti-symmetrical in the angle-ply stacking sequence.


2007 ◽  
Vol 348-349 ◽  
pp. 725-728 ◽  
Author(s):  
Omer Soykasap ◽  
Şükrü Karakaya

In this study, the structural optimization of laminated composite plates for maximum buckling load capacity is performed by using genetic algorithm. The composite plate under consideration is a 64-ply laminate made of graphite/epoxy, is simply supported on four sides, and subject to in-plane compressive static loads. The critical buckling loads are determined for several load cases and different plate aspect ratios using 2-ply stacks of 02, ±45, 902. The problem has multiple global solutions, the results of which are compared with previously published results.


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