Sensitivity of the seismic response of monopile-supported offshore wind turbines to soil variability

The expansion of the offshore wind industry in areas with high seismicity has led to engineering challenges related to the design of the offshore wind turbines (OWTs). Monopiles, i.e., tubular steel piles of large outer diameter, low aspect ratio (penetration depth over outer diameter), and relatively thin pile wall, are traditionally the...

Non-Local Effects of Support Structure Diameter on Wave Induced Fatigue Loads of Monopile-based Offshore Wind Turbines

One of the main cost drivers of an offshore wind power plant are the support structures of the wind turbines, it is therefore of primary importance to optimize their design. Among the support structures available, the concept most widely adopted is the monopile-based support structure, whose design is often fatigue-driven. Offshore structures...

Seismic response of monopile foundations for offshore wind turbines: from 3D to 1D modelling of soil-foundation interaction

New offshore wind farms consisting of monopile-founded Offshore Wind Turbines (OWTs) are to be built in earthquake-prone areas. To design the monopile foundation and to accurately define the dynamic response of an OWT, the soil-monopile-superstructure interaction should be modelled properly. Due to the fact that the Three-Dimensional (3D) Finite...

Dynamic Finite Element Modelling of Pile Tip Deformation

Pile tip damage due to impact with an object (boulder) during the driving process of monopiles is of main concern in the offshore wind sector. Numerical modelling could accurately describe this failure mechanism and used as a tool in practice but also for the development of appropriate guidelines. In this research project, dynamic Finite Element...

Monopile foundation modeling in the frequency domain for Offshore Wind Turbines

The offshore wind industry is a quickly growing market because the increasing demand for clean energy sources. Large wind speeds and the abundance of potential wind farm locations make Offshore Wind Turbines an interesting solution. Because of high continuous dynamic loading and extreme environmental conditions, the structural design requires a...

Frequency Domain Fatigue Analysis of Offshore Wind Monopile Support Structure: For the Purpose of Offshore Wind Farm Optimization

The preliminary design of wind turbine support structures within an offshore wind farm plays a significant role in decreasing the costs involved and is pivotal in establishing the wind sector as a leading contributor towards a sustainable future. During the early design stages, the optimization of structural dimensions, which involves a large...

Re-designing the Vibro-drill for post-installation retrieval: Redesigning the Vibro-drill to include functionalities for retrieval. Report on the design process, structural analysis, the detailed design and recommendations to GBMWorks

With increasing diameters of offshore monopile foundations, impact hammers require more energy per blow in order to drive them into the seabed. This does not only increase the fatigue loading on the monopile, but it also increases underwater noise that affects marine life. The increase in installation costs due to additional material on the...

The Macro-Element Method for Integrated Analyses of Offshore Wind Turbines

Offshore wind energy is considered a necessary renewable energy resource, that may stimulate the transition from fossil fuels. Following the successful development in Western Europe, offshore wind is quickly gaining momentum in the Asia-Pacific region. At variance with North Sea-based offshore wind turbines, structures installed in the Asia...

Input of advanced geotechnical modelling to the design of offshore wind turbine foundations (Apport de la modélisation géotechnique avancée au dimensionnement de fondations d’éoliennes offshore)

The offshore wind sector is skyrocketing worldwide, with a clear trend towards wind farms installed in increasingly deep waters and harsh marine environments. This is posing significant engineering challenges, including those regarding the design of support structures and foundations for offshore wind turbines (OWTs). Substantial research...

A Winkler Model for the Seismic Analysis of Monopile Foundations: An Exploratory Study on the Modelling of Soil-Structure Interaction during Earthquakes

The growing interest in the development of offshore wind farms in seismic active areas demands a better insight into the requirements earthquakes impose on the design of wind turbine foundations. The complexity of the soil-structure interaction (SSI) during an earthquake results in large uncertainties in the design process of a monopile...

Offshore Wind Turbine Monopile Foundation Installation with a Dynamic Positioned Vessel: A feasibility study by modeling

After years of using fossil fuel, the transition to renewable energy sources need to be made to limit the increase in temperature and to support the future energy demand. To support and speed up the transition phase from fossil fuels to renewables it is necessary to decrease the costs. Offshore Wind Turbines are widely used for the production of...

Incorporating the nonlocality of a nonlinear continuum in an effective 1D model for monopile foundations

World energy consumption rises every year. Therefore, producing renewable and<br/>sustainable energy is necessary to protect the viability of this planet. The most well-known and promising form of renewable energy is that of wind power. The limited space in terrestrial areas yielded motivation to the growth of offshore wind industry. Offshore...

The Effect of Stress Wave Dispersion on the Drivability Analysis of Large-Diameter Monopiles

Due to the increasing need for energy from renewable resources, a large number of offshore wind farms are planned to be constructed in the near future. Despite the plethora of available foundation concepts for offshore wind turbines, the monopile foundation is the most widely adopted concept in practice. To predict the installation process for a...

Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for two soil-structure interaction (SSI) models to assess the initial soil stiffness for offshore wind turbine foundations. This stiffness has a defining influence on the first natural frequency of offshore wind turbines (OWTs),...