Optimum design of composite laminates for minimum thickness

This paper proposes a procedure for the optimum design of composite laminates under probabilistic considerations. The problem is formulated to consider the minimization of laminate weight as the objective function and the reliability requirements as the constraints. Both system-level and element-level reliabilities are considered. The first-order reliability method (FORM) is used to estimate the reliability of each ply group, and system reliability is computed based on series or parallel system assumptions. The Tsai-Wu strength criterion is adopted to derive the limit state function of individual ply groups in the laminate. The gradient and sensitivity information of the objective function and the constraints with respect to the design variables are obtained by using sensitivity analysis based on the composite plate theory. Thus the proposed procedure brings together modern concepts of reliability analysis, composite laminate behavior and nonlinear optimization to develop a rational and practical procedure for the optimum design of composite laminates. Numerical examples are presented to demonstrate the effectiveness of the proposed method.

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Optimum design of fatigue-resistant composite laminates using hybrid algorithm

Composite Structures ◽

10.1016/j.compstruct.2017.01.064 ◽

2017 ◽

Vol 168 ◽

pp. 178-188 ◽

Cited By ~ 9

Author(s):

H. Arda Deveci ◽

H. Seçil Artem

Keyword(s):

Optimum Design ◽

Composite Laminates ◽

Hybrid Algorithm

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Optimum Design of Composite Pressure Vessel Based on 3-Dimensional Failure Criteria

Volume 2: Computer Technology and Bolted Joints ◽

10.1115/pvp2019-93816 ◽

2019 ◽

Author(s):

J. Sakai ◽

Y. H. Park

Keyword(s):

Optimum Design ◽

Pressure Vessel ◽

Composite Laminates ◽

Three Dimensional ◽

Weight Ratio ◽

High Strength ◽

Failure Criteria ◽

Pressure Vessels ◽

Fiber Reinforced ◽

3D Elasticity

Abstract Anisotropic composite cylinders and pressure vessels have been widely employed in automotive, aerospace, chemical and other engineering areas due to high strength/stiffness-to-weight ratio, exceptional corrosion resistance, and superb thermal performance. Pipes, fuel tanks, chemical containers, rocket motor cases and aircraft and ship elements are a few examples of structural application of fiber reinforced composites (FRCs) for pressure vessels/pipes. Since the performance of composite materials replies on the tensile and compressive strengths of the fiber directions, the optimum design of composite laminates with varying fiber orientations is desired to minimize the damage of the structure. In this study, a complete mathematical 3D elasticity solution was developed, which can accurately compute stresses of a thick multilayered anisotropic fiber reinforced pressure vessel under force and pressure loadings. A rotational variable is introduced in the formalism to treat torsional loading in addition to force and pressure loadings. Then, the three-dimensional Tsai-Wu criterion is used based on the analytical solution to predict the failure. Finally, a global optimization algorithm is used to find the optimum fiber orientation and their best combination through the thickness direction.

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Optimum Design of Sunken Reinforced Enclosures under Buckling Condition

Applied Sciences ◽

10.3390/app10238449 ◽

2020 ◽

Vol 10 (23) ◽

pp. 8449

Author(s):

Mostafa Omidi Bidgoli ◽

Kazem Reza Kashyzadeh ◽

Seyed Saeid Rahimian Koloor ◽

Michal Petrů ◽

Nima Amiri

Keyword(s):

Finite Element ◽

Critical Load ◽

Optimum Design ◽

Analytical Method ◽

Design Principles ◽

Offshore Structures ◽

Finite Element Analyses ◽

Marine Structures ◽

Minimum Thickness ◽

Good Agreement

Increasing the lifetime and improving the performance of structures through redesign and optimization are important, especially in marine structures. In general, there are two main groups of marine structures: onshore and offshore structures. Most marine structures are offshore, and these are divided into two categories: floating or sunken. One of the important parameters in the design of sunken structures is the critical load resulting from the buckling of walls, which can cause damage to the structure. In the present paper, three rectangular aluminum and steel compartments of different conditions and sizes were modeled using design analysis methods. Then, different finite element analyses were performed, and the compartments were optimized to reduce the weight of the structure. Finally, the buckling results of three types of rectangular reinforced compartments were calculated and were compared with each other. The results show that the stresses calculated using the analytical method are in good agreement with the results of the finite element analyses. In addition, the weight of the compartment is reduced by utilizing the reinforced conductors in accordance with the design principles and considering the minimum thickness.

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