On the Use of the Finite Element Method for the Design of Offshore Wind Turbine Foundations

2019 ◽  
pp. 193-204
Author(s):  
Hendrik Sturm ◽  
Lars Andresen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
The Finite Element Method ◽  
Element Method

Analysis of Octagonal Pile Supporting Offshore Wind Turbines Under Wave Loads

2014 ◽  
Author(s):  
Serena Lim ◽  
Longbin Tao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Computational Cost ◽  
Offshore Wind ◽  
Computational Time ◽  
Offshore Wind Turbine ◽  
Wave Loads ◽  
Element Method

Offshore wind energy development has gained considerable momentum around the world as wind is stronger and steadier offshore compared to land. This has led to a significant increase in production in recent years, especially offshore wind turbine embedded in shallow waters, such as the recent large scale offshore wind farms in the Northern Europe region. Being at the offshore waters, the wind turbines are subjected to harsh environment. The pile supporting the wind turbine must be reliable and able to withstand such sea condition. It is an important part of the design to study the structural behaviour of the piles under the wave loads. Due to the significant capital cost associated with the fabrication of the large circular cylinders, a new recommended innovative design to overcome such problem is to substitute the circular cylinder with a vertical monopile of octagonal cross-sectional shape. This paper describes the development of an efficient numerical model for structural analysis of wave interaction with octagonal pile using a modified semi analytical Scaled Boundary Finite Element Method (SBFEM). In contrast to the existing solutions obtained using the traditional methods such as the Finite Element Method (FEM) which typically suffer from high computational cost and the Boundary Element Method (BEM) which faces limitation from fundamental equations and problems with singularities. The most prominent advantage that SBFEM has over the FEM is in terms of the number of elements used for calculation and hence a reduction in computational time. When compared with BEM, the SBFEM does not suffer from computational stability problems.

Study of Grouted Connections in Offshore Monopile Structures

2019 ◽  
Author(s):  
Efstathios E. Theotokoglou ◽  
Georgia Papaefthimiou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Wind Turbine ◽  
Static Loading ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
The Finite Element Method ◽  
Analysis Problem ◽  
Mesh Density

Abstract In this paper the grouted connection (GC) of an offshore wind turbine is studied. The study is performed numerically by the finite element method (FEM). Initially, a description of the connection, its geometrical variations and its materials are presented. Moreover, analytical types about the deformation of the connection are presented. Subsequently, the analysis of the three dimensioned problem is performed numerically and the procedure as well as the parameters used, are given step by step. The case of the contact analysis problem is also studied. Practical issues such as mesh density and materials interaction are confronted. Finally, the stress state (SS) will be given in the analysis results, in order to specify the behavior of the connection under static loading.

scholarly journals Study on the Effect of Different Delamination Defects on Buckling Behavior of Spar Cap in Wind Turbine Blade

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jianwei Li ◽  
Jinghua Wang ◽  
Leian Zhang ◽  
Xuemei Huang ◽  
Yongfeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Reference Value ◽  
Element Model ◽  
Theory And Practice ◽  
The Finite Element Method ◽  
Buckling Behavior ◽  
Element Method

Delamination is detrimental to the composite materials, and it may occur in the manufacturing process of the unidirectional laminate of the spar cap in wind turbine blades. This paper studies the effect of different delamination defects on the strength of the unidirectional laminate. The finite element model of laminate with different delamination areas and delamination heights is established using solid elements. The eigenvalues of laminates have different parameters calculated based on the finite element method. The final coupon test is used to verify the conclusions of simulation results. The finite element method presented in this study shows excellent capabilities to predict the buckling behavior of the laminate. The buckling eigenvalue of tested laminate is negatively correlated with the delamination area and positively correlated with the delamination height under the edgewise load. The S11, which is too high at the boundary of the delamination region, plays a significant role in buckling failure. It has a particular reference value for testing the laminate of blade both in theory and practice.

scholarly journals Diseño y simulación preliminar del cubo del rotor para una turbina eólica de 50-kW clase II, de acuerdo a la norma IEC-61400-2

2020 ◽  
pp. 1-13
Author(s):  
José Luis Colín-Martínez ◽  
Victor Lopez-Garza ◽  
Isaac Hernández-Arriaga ◽  
María Guadalupe Navarro-Rojero
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Farms ◽  
The Finite Element Method ◽  
Ansys Software ◽  
International Standard ◽  
Previous Design ◽  
Element Method

Currently, wind energy in Mexico is growing and the same is happening worldwide, so projects with national technologies for the manufacture of wind turbine components must be developed. In this work, a proposal is made for the design of the hub of the rotor for a 50-kW turbine, the objective is to make a new proposal to improve the previous design of project P07 of the Centro Mexicano de Innovación en Energía Eólica (CEMIEEólico), which has a welded mechanical hub for a prototype turbine 30 kW. In addition, a simulation is performed through analysis of the finite element method (FEA) by applying certain load elements with the simplified load method of the international standard IEC 61400-2. In these simulations, the load cases of the norm that directly influence the cube are analyzed, then simulated in the ANSYS software to validate the proposed design, mainly analyzing the stresses and deformations. The results obtained will serve as a reference to manufacture the cube and evaluate the feasibility of carrying out a commercial stage with a view to making national components for wind farms.

Numerical Simulation of Ship Collision With Gravity Base Foundations of Offshore Wind Turbines

2013 ◽  
Author(s):  
Thorben Hamann ◽  
Torben Pichler ◽  
Jürgen Grabe
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cost Effective ◽  
Offshore Structures ◽  
Contact Forces ◽  
Offshore Wind ◽  
The Finite Element Method ◽  
Effective Manner ◽  
Ship Collision ◽  
Element Method

For the installation of offshore foundations several countries (e.g. Germany) require a proof of averting environmental disasters in case of ship collision. The aim is to prevent possible discharge of supplies or even loss of the vessel. Especially for gravity base foundations this load case is problematic due to their larger stiffness and mass compared to monopiles, tripods or jacket foundations. The finite element method provides a powerful tool to predict the collision behaviour in a realistic way taking into account the complex interaction between vessel, foundation and soil. The collision between a fully loaded single hull tanker and a gravity base foundation is subject of numerical analysis. The calculated contact forces between vessel and foundation are compared to a simplified calculation approach. For evaluation of the foundation deformations and areas of failure of the vessel are investigated. The influence of the water depth, the diameter of the foundation and an embedment in the seabed are determined in a parametric study. It can be shown that the finite element method is a suitable approach for investigation of the collision behaviour of offshore structures. The design of gravity base foundations can be optimized with respect to ship collision in a fast and cost-effective manner using this method.

Wave Diffraction Forces on Offshore Wind Turbine Piles With an Octagonal Cross Section

2013 ◽  
Author(s):  
Serena Lim ◽  
Longbin Tao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Diffraction ◽  
Offshore Wind ◽  
Circular Cylinders ◽  
Computational Time ◽  
Offshore Wind Turbine ◽  
Computational Stability ◽  
Irregular Frequency ◽  
Element Method

Traditional offshore wind turbines are normally supported by circular monopiles which are fabricated by rolling thick plates and welding them longitudinally. Due to the significant capital cost associated with the fabrication of such large circular cylinders, a new recommended innovative design to overcome such problem is introduced by replacing the circular cylinder with a vertical pile of octagonal cross-sectional shape. An efficient and very accurate semi-analytical/numerical solution based on the Scaled Boundary Finite Element Method (SBFEM) is developed to calculate the wave diffraction forces acting on the octagonal cylinders where no fundamental solutions known exist. Compared to the traditional Boundary Element Method (BEM), the SBFEM is free from the irregular frequency difficulty which means that it does not suffer from computational stability problems at sharp corners. The SBFEM solution also exhibits an enormous reduction of elements used to calculate the wave diffraction compared to the Finite Element Method (FEM), hence, a significant reduction in computational time. The SBFEM computation of the diffraction force demonstrates highly accurate results with a small number of surface elements. The presented method shows significant advantages, and is suitable for engineering applications especially the wave-structure interaction in the practical design.

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