Multi-objective optimization of sandwich composite pressure hull for decreasing weight and drag force and increasing buckling load capacity

Due to the wide range of variables involved and sophisticated analysis techniques required, optimum structural design of composite submersible pressure hull is known to be a challenge for designers. The major challenge involved in the coupled design problem is to handle multiple conflicting objectives. The problem with its proper consideration through multi-objective optimization is studied in this paper. Minimize the buoyancy factor and maximize buckling load capacity of the submersible pressure hull under hydrostatic pressure is considered as the objective function to reach the operating depth equal to 6000m. Finite element analysis of composite elliptical submersible pressure hull is performed using ANSYS parametric design language (APDL). The constraints based on the failure strength of the hulls are considered. The fiber orientation angles and the thickness in each layer, the radii of the ellipse, the ring beams and the stringers dimensions are taken as design variables. Additionally, a sensitivity analysis is performed to study the influence of the design variables up on objectives and constraints functions. Results of this study provide a valuable reference for designers of composite underwater vehicles.

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Finite Element Modelling and Multi-Objective Optimization of Composite Submarine Pressure Hull Subjected to Hydrostatic Pressure

Materials Science Forum ◽

10.4028/www.scientific.net/msf.953.53 ◽

2019 ◽

Vol 953 ◽

pp. 53-58 ◽

Cited By ~ 3

Author(s):

Elsayed Fathallah

Keyword(s):

Hydrostatic Pressure ◽

Parametric Design ◽

Epoxy Composite ◽

Load Capacity ◽

Optimization Process ◽

Valuable Insight ◽

Multi Objective Optimization ◽

Multi Objective ◽

Optimized Model ◽

Better Than

Excellent mechanical behavior and low density of composite materials make them candidates to replace metals for many underwater applications. This paper presents a comprehensive study about the multi-objective optimization of composite pressure hull subjected to hydrostatic pressure to minimize the weight of the pressure hull and maximize the buckling load capacity according to the design requirements. Two models were constructed, one model constructed from Carbon/Epoxy composite (USN-150), the other model is metallic pressure hull constructed from HY100. The analysis and the optimization process were completely performed using ANSYS Parametric Design Language (APDL). Tsai-Wu failure criterion was incorporated in the optimization process. The results obtained emphasize that, the submarine constructed from Carbon/Epoxy composite (USN-150) is better than the submarine constructed from HY100. Finally, an optimized model with an optimum pattern of fiber orientations was presented. Hopefully, the results may provide a valuable insight for the future of designing composite underwater vehicles.

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Multi-objective optimization for lightweight design of bi-directional functionally graded beams for maximum frequency and buckling load

Composite Structures ◽

10.1016/j.compstruct.2021.114691 ◽

2021 ◽

pp. 114691

Author(s):

Rasha M. Abo-bakr ◽

Rabab A. Shanab ◽

Mohamed A. Attia

Keyword(s):

Lightweight Design ◽

Functionally Graded ◽

Buckling Load ◽

Maximum Frequency ◽

Multi Objective Optimization ◽

Multi Objective

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Study on 3D Shape Optimization for Hydrodynamic Journal Bearing Using Goal Attainment Multi-Objective Function

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.319.505 ◽

2013 ◽

Vol 319 ◽

pp. 505-509 ◽

Cited By ~ 1

Author(s):

Xiao Ping Pang ◽

Jin Chen

Keyword(s):

Film Thickness ◽

Shape Optimization ◽

Goal Attainment ◽

Journal Bearing ◽

Load Capacity ◽

Axial Direction ◽

Three Dimensions ◽

Multi Objective Optimization ◽

Multi Objective ◽

Hydrodynamic Journal Bearing

This paper is focused on multi-objective optimization to find the best performance related to the geometrical design of the hydrodynamic journal bearing in three dimensions 3D. The mathematical model for 3D film thickness profile was driven using Fourier’s series function and axial waviness value to represent in circumferential and axial direction respectively. A Goal attainment function was used as an optimization tool with goals to minimize the power loss and side leakage and to maximize the load capacity, while the amplitude (a), number of wave (m) and Fourier's series coefficients of the general film thickness were taken as design variables subjected to several bounds and constraints. The optimized results show the cylindrical plain bearing is the best to load capacity due to changing the axial shape does not enhance the load capacity without violation of the minimum film thickness. Comparison was made between goal attainment multi-objective optimization and GA single-objective optimization. The new method for shape optimization based on 3D general film thickness is more evident than GA.

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Multi-objective optimization of composite angle grid plates for maximum buckling load and minimum weight using genetic algorithms and neural networks

Composite Structures ◽

10.1016/j.compstruct.2019.111450 ◽

2019 ◽

Vol 229 ◽

pp. 111450 ◽

Cited By ~ 5

Author(s):

Amir Ehsani ◽

Hamid Dalir

Keyword(s):

Neural Networks ◽

Genetic Algorithms ◽

Minimum Weight ◽

Buckling Load ◽

Multi Objective Optimization ◽

Multi Objective

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Multi-objective design optimization of composite submerged cylindrical pressure hull for minimum buoyancy factor and maximum buckling load capacity

Defence Technology ◽

10.1016/j.dt.2020.06.017 ◽

2020 ◽

Cited By ~ 1

Author(s):

Muhammad Imran ◽

Dongyan Shi ◽

Lili Tong ◽

Ahsan Elahi ◽

Hafiz Muhammad Waqas ◽

...

Keyword(s):

Design Optimization ◽

Load Capacity ◽

Buckling Load ◽

Multi Objective

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A method for the optimal design of low-density polymer foam core sandwiches using FEA and multiobjective optimization of design variables

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0181 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Çağrı Uzay ◽

Durmuş Can Acer ◽

Necdet Geren

Keyword(s):

Optimal Design ◽

Load Capacity ◽

Low Density ◽

Foam Core ◽

Multi Objective Optimization ◽

Polymer Foam ◽

Multi Objective ◽

The Core ◽

Design Variables ◽

Bending Load

Abstract In this study, a generative method was introduced to determine the optimal design of low-density polymer foam core sandwiches using finite element analysis (FEA) and multi-objective optimization of design variables without needing experiments. The method was also assessed. The sandwich structures were designed based on woven plain carbon fiber fabrics, PVC foam core, and polymer epoxy matrix. The design variables are the core density (40, 48, 60 kg/m3) and the core thickness (16, 20, 25 mm). The sandwich configurations were subjected to FEA under the three-point bending (TPB) loads. The force-reaction curves obtained from FEA were compared to experimental data available in the literature. Excellent agreement was achieved between the experimental and FEA simulated results at the linear elastic region of the curves. Thus, it allowed predicting the bending stiffness of the sandwiches via TPB analysis. Besides, a two-way analysis of variance (ANOVA) was conducted to determine the effects of parameters on sandwich mass and bending load capacity. Multi-objective optimization of design variables was also carried out according to the constructed mathematical models. The method provided in this study eases both designer’s and researcher’s work to obtain the optimal design variables without making costly experiments.

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