scholarly journals Structural Optimization Method for the Transition Section in Composite Bucket Foundations of Offshore Wind Turbines

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3230 ◽  
Author(s):  
Puyang Zhang ◽  
Yunlong Xu ◽  
Conghuan Le ◽  
Hongyan Ding ◽  
Yaohua Guo
Keyword(s):  
Structural Optimization ◽  
Hybrid Genetic Algorithm ◽  
Optimization Method ◽  
The Body ◽  
Offshore Wind ◽  
Utilization Rate ◽  
Force Transmission ◽  
Transition Section ◽  
Finite Element Software ◽  
Thin Walled

A two-step structural optimization method was proposed to select the transition section of a composite bucket foundation (CBF). In the first step, based on the variable density method, a solid isotropic microstructures with penalization (SIMP) interpolation model was established under specific load conditions and boundary conditions. The solution of force transmission path and the topology of the transition section in six forms (e.g., linear, arc-shaped, linear thin-walled, and arc-shaped thin-walled) were optimized. Afterwards, finite element software ABAQUS was used to verify this model. Results show that the utilization rate of the arc-shaped thin-walled structure was the largest, and its basic transmission force was more straightforward together with smaller cross-section size at the same height and smaller influence on spoiler flow. In the second step, the detailed optimization of CBF was carried out using mathematical programming. Under the premise of minimum total construction cost, the body shape parameters of each part were set as design variables satisfying the corresponding strength, stiffness, and stability conditions; meanwhile, the minimum total structure weight was set as the objective function. MATLAB was used to solve the sequence quadratic programming (SQP) algorithm and hybrid genetic algorithm, and the optimal body parameters were obtained.

scholarly journals An Optimization Method for the Configuration of Inter Array Cables for Floating Offshore Wind Farm

2017 ◽  
Author(s):  
Yann Poirette ◽  
Martin Guiton ◽  
Guillaume Huwart ◽  
Delphine Sinoquet ◽  
Jean Marc Leroy
Keyword(s):  
Wind Farm ◽  
Optimization Problem ◽  
Initial Point ◽  
Trust Region ◽  
Optimization Method ◽  
Global Optimum ◽  
Offshore Wind ◽  
Finite Element Software ◽  
Constrained Problems ◽  
Floating Offshore Wind Turbines

IFP Energies nouvelles (IFPEN) is involved for many years in various projects for the development of floating offshore wind turbines. The commercial deployment of such technologies is planned for 2020. The present paper proposes a methodology for the numerical optimization of the inter array cable configuration. To illustrate the potential of such an optimization, results are presented for a case study with a specific floating foundation concept [1]. The optimization study performed aims to define the least expensive configuration satisfying mechanical constraints under extreme environmental conditions. The parameters to be optimized are the total length, the armoring, the stiffener geometry and the buoyancy modules. The insulated electrical conductors and overall sheath are not concerned by this optimization. The simulations are carried out using DeepLines™, a Finite Element software dedicated to simulate offshore floating structures in their marine environment. The optimization problem is solved using an IFPEN in-house tool, which integrates a state of the art derivative-free trust region optimization method extended to nonlinear constrained problems. The latter functionality is essential for this type of optimization problem where nonlinear constraints are introduced such as maximum tension, no compression, maximum curvature and elongation, and the aero-hydrodynamic simulation solver does not provide any gradient information. The optimization tool is able to find various local feasible extrema thanks to a multi-start approach, which leads to several solutions of the cable configuration. The sensitivity to the choice of the initial point is demonstrated, illustrating the complexity of the feasible domain and the resulting difficulty in finding the global optimum configuration.

Lifting Technique of Composite Bucket Foundation for Offshore Wind Turbines

2020 ◽  
Author(s):  
Hongyan Ding ◽  
Zuntao Feng ◽  
Puyang Zhang ◽  
Conghuan Le
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Large Scale ◽  
Element Model ◽  
Offshore Wind ◽  
Force Transmission ◽  
Element Analysis ◽  
Bucket Foundation ◽  
Transition Section ◽  
Section Structure

Abstract The onshore pre-fabrication technology for composite bucket foundations takes “prefabrication-assembly-lifting” as the core concept. The practice of pre-fabrication of upper and lower structures is prefabricated respectively. In the research of hoisting engineering technology, combined with the structural form and construction requirements of composite bucket foundation, the assembly scheme of the upper prestressed concrete transition section and the lower steel bucket and the hoisting scheme of integral foundation with compartments were designed. The finite element model in the lifting process of composite bucket foundation was established by the large-scale general finite element analysis software ABAQUS. For the optimization analysis of the lifting point arrangement during hoisting process, the number, position and arrangement form of lifting points are simulated and analyzed. The results show that the maximum value of the principal stress of the concrete transition section structure appears in the assembly stage with the lower steel bucket, and the structure checking calculation should be carried out as the most unfavorable lifting condition in construction; the peak point of structural stress is at the junction of girder and secondary beams and inner ring beams of concrete roof, which belongs to the weak position of force transmission. In construction, it should be paid attention to as the key part of monitoring to ensure composite bucket foundation is under reasonable stress and the stability in the lifting process. The research results can provide guidance and reference for the future batch production and standardization production construction for composite bucket foundations.

The Truss Structural Optimization Design Based on Improved Hybrid Genetic Algorithm

2010 ◽  
Vol 163-167 ◽  
pp. 2304-2308
Author(s):  
Feng Guo Jiang ◽  
Zhen Qing Wang
Keyword(s):  
Genetic Algorithm ◽  
Local Search ◽  
Structural Optimization ◽  
Optimization Design ◽  
Hybrid Genetic Algorithm ◽  
Optimization Method ◽  
Gradient Algorithm ◽  
General Search ◽  
Genetic Arithmetic ◽  
Iteration Analysis

Genetic arithmetic operators in genetic algorithm be improved , and a hybrid genetic algorithm of a gradient algorithm combining with the genetic algorithm be given against to the defects such as premature，slow on convergence rate，weak in the ability of local search ，all these appeared on the progress of genetic algorithm's iteration. Analysis result indicate that not only strong on the local search capacity of gradient algorithm be exhibited but also strong on the general search capacity of genetic algorithm be combined based on the hybrid genetic algorithm ,which make phenomenon of premature avoid, and the rate of convergence be improved greatly. Concrete calculated example indicated that the hybrid genetic algorithm is an effective structural optimization method.

STRUCTURAL OPTIMIZATION ALGORITHM FOR VEHICLE SUSPENSIONS

2011 ◽  
Vol 35 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Marc J. Richard ◽  
Mohamed Bouazara ◽  
Laouhari Khadir ◽  
Guoqiang Q. Cai
Keyword(s):  
Structural Optimization ◽  
Optimization Algorithm ◽  
Optimization Method ◽  
Structural Constraints ◽  
Vehicle Suspensions ◽  
Finite Element Software ◽  
Car Suspension ◽  
Acceleration Sensors ◽  
Set Up

Stringent tolerances on mechanical components have created increasingly severe demands on the quality of new mechanical designs. The mathematical models used to analyze the various types of mechanical systems these days need to incorporate an optimization algorithm capable of minimizing the levels of vibrations coming from varied sources. The suggested method is based on the parallel combination of three methods; the Rayleigh-Ritz approach (to determine the first eigenfrequencies) which is incorporated into an efficient multicriterion optimization process based on the ESO (Evolutionary Structural Optimization) method and the finite element software ABAQUS. The analytical resolution and the numerical calculations of the mechanical component are, finally, validated by an experimental set-up which exploits a frequency analyser, acceleration sensors and an excitation hammer. The effectiveness of this approach is also demonstrated in the analysis of an upper car suspension arm. By gradually removing material from the initial car suspension design, the frequency of the component can be controlled in order to optimize the structural constraints.

Structural Optimization of Composite Panel with Lamination Parameters and Equivalent Stiffness Laminate Method

2014 ◽  
Vol 496-500 ◽  
pp. 429-435
Author(s):  
Xiao Ping Zhong ◽  
Peng Jin
Keyword(s):  
Genetic Algorithm ◽  
Structural Optimization ◽  
Composite Structure ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Composite Panel ◽  
Analysis Tool ◽  
Equivalent Stiffness ◽  
Lamination Parameters ◽  
Design Variables

Firstly, a two-level optimization procedure for composite structure is investigated with lamination parameters as design variables and MSC.Nastran as analysis tool. The details using lamination parameters as MSC.Nastran input parameters are presented. Secondly, with a proper equivalent stiffness laminate built to substitute for the lamination parameters, a two-level optimization method based on the equivalent stiffness laminate is proposed. Compared with the lamination parameters-based method, the layer thicknesses of the equivalent stiffness laminate are adopted as continuous design variables at the first level. The corresponding lamination parameters are calculated from the optimal layer thicknesses. At the second level, genetic algorithm (GA) is applied to identify an optimal laminate configuration to target the lamination parameters obtained. The numerical example shows that the proposed method without considering constraints of lamination parameters can obtain better optimal results.

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