scholarly journals The effect of buckling and post-buckling behavior of laminated composite plates with rotationally restrained and Pasternak foundation on stacking sequence optimization

2020 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Sina Farahani ◽  
Mojtaba Fathi ◽  
Ebrahim Nazarimofrad
Keyword(s):  
Laminated Composite ◽  
Composite Plates ◽  
Stacking Sequence ◽  
Pasternak Foundation ◽  
Laminated Composite Plates ◽  
Sequence Optimization ◽  
Stacking Sequence Optimization ◽  
Buckling Behavior ◽  
Post Buckling

scholarly journals Metaheuristic Optimization of Laminated Composite Plates with Cut-Outs

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1235
Author(s):  
Celal Cakiroglu ◽  
Kamrul Islam ◽  
Gebrail Bekdaş ◽  
Sanghun Kim ◽  
Zong Woo Geem
Keyword(s):  
Search Algorithm ◽  
Harmony Search ◽  
Laminated Composite ◽  
Composite Plates ◽  
Structural Performance ◽  
Stacking Sequence ◽  
Laminated Composite Plates ◽  
Sequence Optimization ◽  
Stacking Sequence Optimization ◽  
Aspect Ratios

The stacking sequence optimization of laminated composite plates while maximizing the structural performance or minimizing the weight is a subject investigated extensively in the literature. Meanwhile, research on the optimization of laminates with cut-outs has been relatively limited. Cut-outs being an indispensable feature of structural components, this paper concentrates on the stacking sequence optimization of composite laminates in the presence of circular cut-outs. The buckling load of a laminate is used as a metric to quantify the structural performance. Here the laminates are modeled as carbon fiber-reinforced composites using the finite element analysis software, ABAQUS. For the optimization, the widely used harmony search algorithm is applied. In terms of design variables, ply thickness, and fiber orientation angles of the plies are used as continuously changing variables. In addition to the stacking sequence, another geometric variable to consider is the aspect ratio (ratio of the length of the longer sides to the length of the shorter sides of the plate) of the rectangular laminates. The optimization is carried out for three different aspect ratios. It is shown that, by using dispersed stacking sequences instead of the commonly used 0°/±45°/±90° fiber angle stacks, significantly higher buckling loads can be achieved. Furthermore, changing the cut-out geometry is found to have a significant effect on the structural performance.

Relative Post-Buckling Stiffness Calculation of Symmetrically Laminated Composite Plates Using an Exact Finite Strip

2010 ◽  
Vol 123-125 ◽  
pp. 201-204 ◽  
Author(s):  
Seyyed Amir Mahdi Ghannadpour ◽  
Hamid Reza Ovesy
Keyword(s):  
Laminated Composite ◽  
Composite Plates ◽  
Unknown Coefficient ◽  
Laminated Composite Plates ◽  
Total Strain Energy ◽  
Finite Strip ◽  
Finite Strip Method ◽  
Buckling Behavior ◽  
Out Of Plane ◽  
Post Buckling

This paper presents the theoretical developments of an exact finite strip for the buckling and initial post-buckling analyses of symmetrically laminated composite plates. The so-called exact finite strip is developed based on the concept that it is effectively a plate. The present method, which is designated by the name Full-analytical Finite Strip Method in this paper, provides an efficient and extremely accurate buckling solution. In the development process, the Von-Karman’s equilibrium equation is solved exactly to obtain the buckling loads and the corresponding form of out-of-plane buckling deflection modes. The investigation of thin flat plate buckling behavior is then extended to an initial post-buckling study with the assumption that the deflected form immediately after the buckling is the same as that obtained for the buckling. The post-buckling study is effectively a single-term analysis, which is attempted by utilizing the so-called semi-energy method. In this method, the Von-Karman’s compatibility equation governing the behavior of symmetrically laminated composite plates is used together with a consideration of the total strain energy of the plate. Through the solution of the compatibility equation, the in-plane displacement functions are developed in terms of the unknown coefficient in the assumed out-of-plane deflection function. These in-plane and out-of-plane deflected functions are then substituted in the total strain energy expressions and the theorem of minimum total potential energy is applied to solve for the unknown coefficient. The developed method is subsequently applied to analyze the initial post-buckling behavior of some representative thin flat plates for which the results are also obtained through the application of a semi-analytical finite strip method. Through the comparison of the results and the appropriate discussion, the knowledge of the level of capability of the developed method is significantly promoted.

scholarly journals Experimental and Numerical Buckling Analyses of Laminated Composite Plates under Temperature Effects

2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
Emin Ergun
Keyword(s):  
Composite Plate ◽  
Numerical Solutions ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Load ◽  
Fibre Reinforcement ◽  
Stacking Sequence ◽  
Laminated Composite Plates ◽  
Different Temperatures ◽  
Good Agreement

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.

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