Optimal Design of Composite Laminate With Uncertainty in Loading and Material Properties Considered

2005 ◽  
Author(s):  
Tae-Uk Kim ◽  
In Hee Hwang ◽  
Hyo-Chol Sin
Keyword(s):  
Optimal Design ◽  
Material Properties ◽  
Composite Laminates ◽  
Buckling Load ◽  
Optimization Approach ◽  
Stacking Sequence ◽  
Simulation Techniques ◽  
Aspect Ratios ◽  
The One ◽  
Efficiency And Reliability

Optimal design of composite laminates with uncertain in-plane loadings and material properties is considered. The stacking sequence is designed to have maximum buckling load based on anti-optimization approach. To consider the above-mentioned uncertain properties, the convex modeling and Monte Carlo simulation techniques are used in calculating objective function. For the stacking sequence optimization, it is used the modified genetic algorithm which handles the discrete ply angles and the constraints easily. Numerical results are given for rectangular laminates of various aspect ratios. The optimal solutions from the deterministic and the stochastic cases are obtained and it is demonstrated the importance of considering uncertainty. The buckling load carried by a deterministic design is much less than the one carried by a design uncertainty considered when both are subjected to uncertain loads. Also, it is examined the effects of the method for considering uncertainty on the optimization process in the light of computational efficiency and reliability of solutions obtained.

Layup Optimization for Maximum Buckling Load Considering Bounded Uncertainty

2006 ◽  
Author(s):  
Tae-Uk Kim ◽  
In Hee Hwang ◽  
JaeYeul Shim
Keyword(s):  
Composite Laminates ◽  
Buckling Load ◽  
Optimization Approach ◽  
Stacking Sequence ◽  
Optimal Solutions ◽  
Simulation Techniques ◽  
Aspect Ratios ◽  
Modified Genetic Algorithm ◽  
The One ◽  
Efficiency And Reliability

Optimal design of composite laminates with uncertain in-plane loadings and material properties is considered. The stacking sequence is designed to have maximum buckling load based on anti-optimization approach. To consider the above-mentioned uncertain properties, the convex modeling, interval analysis and Monte Carlo simulation techniques are used in calculating objective function. For the stacking sequence optimization, it is used the modified genetic algorithm which handles the discrete ply angles and the constraints easily. Numerical results are given for rectangular laminates of various aspect ratios. The optimal solutions from the deterministic and the stochastic cases are obtained and it is demonstrated the importance of considering uncertainty. The buckling load carried by a deterministic design is much less than the one carried by a design uncertainty considered when both are subjected to uncertain loads. Also, it is examined the effects of the method for considering uncertainty on the optimization process in the light of computational efficiency and reliability of solutions obtained.

Multi-Objective Optimal Design of Sandwich Composite Laminates Using Simulated Annealing and FEM

2008 ◽  
Author(s):  
A. Sarhadi ◽  
M. Tahani ◽  
F. Kolahan ◽  
M. Sarhadi
Keyword(s):  
Simulated Annealing ◽  
Optimal Design ◽  
Composite Laminates ◽  
Composite Structures ◽  
Simulated Annealing Algorithm ◽  
Core Layer ◽  
Sandwich Composite ◽  
Surface Layers ◽  
Multi Objective ◽  
Aspect Ratios

Multi-objective optimal design of sandwich composite laminates consisting of high stiffness and expensive surface layers and low-stiffness and inexpensive core layer is addressed in this paper. The object is to determine ply angles and number of surface layers and core thickness in such way that natural frequency is maximized with minimal material cost and weight. A simulated annealing algorithm with finite element method is used for simultaneous cost and weight minimization and frequency maximization. The proposed procedure is applied to Graphite-Epoxy/Glass-Epoxy and Graphite-epoxy/Aluminum sandwich laminates and results are obtained for various boundary conditions and aspect ratios. Results show that this technique is useful in designing of effective, competitive and light composite structures.

Effects of Delamination on the Critical Buckling Load of Glass Fiber Reinforced Epoxy Composite Plates

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
S. Venkatesh ◽  
S. Prakash ◽  
S. Raja ◽  
S. Manigandan ◽  
P. Sivashankari
Keyword(s):  
Composite Laminates ◽  
Epoxy Composite ◽  
Composite Plates ◽  
Vertical Displacement ◽  
Buckling Load ◽  
Buckling Loads ◽  
Critical Buckling Load ◽  
Finite Element Software ◽  
Aspect Ratios ◽  
Glass Fiber Reinforced

The effects of the delamination in the critical buckling load failure of E-Glass /epoxy composite laminates are analysed. The buckling load of rectangular composite plates is determined by carrying out the experimental work for different aspect ratios of range 2 to 3. The specimens are made with unidirectional fibres of orientation (90/45/-45/0)s. The width of long 100 mm and 50 mm at the centre of the plate, a single substantial delamination is made at the mid layer produced by Teflon film using hand lay-up technique. The buckling loads of plates were found by using simply supported boundary condition and kept the other side edges free. The experimental buckling loads were found from the graph drawn for vertical displacement vs load. By drawing the graph for the vertical displacement vs. load, the experimental buckling load can be calculated. Using finite element software of ANSYS 10, the experimental results were validated.

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