Foundation Design of Offshore Wind Turbine Structures – 4 Day Course

ABOUT THE COURSE
The costs of offshore wind are currently, significantly higher than onshore wind. A significant contributor to this higher cost is the cost of the foundations for the turbines. Hence a rational and optimized design of foundation for wind turbines is essential to reduce the overall cost.

This course gives a detailed knowledge about the design and analysis of mono pile, and jacket structure foundations.

This course also includes the soil pile interaction and the dynamic responses.
This course will provide a general overview of the aero-servo-hydro-elastic software Bladed and the
different engineering models behind the code in order to represent the coupled dynamics of offshore wind systems

Following a general introduction to fatigue and fracture, with examples of service failures, current and developing fatigue design and assessment methods will be described. The course will go on to explain the importance of crack/flaw analysis in structural design and safety assessment and illuminate its wide range of applicability.

The course will include both ultimate and fatigue limit state check for the design of these types of
foundations. The uncertainties of various design variables will also be discussed in these lectures. Lastly a reliability based design of suction pile will be covered.

Who Should Attend
Engineers and researchers involved in the design of offshore wind farm foundation, Contracts engineers, Wind turbine Installation companies, Team leaders, Conversion Engineers, Project engineers and managers, offshore controls engineers, Safety inspectors will benefit from attending this course. The course is innovative in both content & structure with a careful balance of theory and practice.

PROGRAMME

Day 1

09.00 – 10.30 Lecture 1: Overview of the whole Wind Turbine structure
Prof. Subhamoy Bhattacharya

10.30 – 11.00 Break

11.00 – 12.30 Lecture 2: Loads on the offshore wind turbine structure
Prof. Subhamoy Bhattacharya

12.30 -13.30 Lunch

13.30 – 15.00 Lecture 3: Consideration for foundation design and the calculations necessary
Prof. Subhamoy Bhattacharya

15.00 – 15.30 Break

15.30 – 17.00 Lecture 4: Geotechnical Site Investigation and Soil behaviour under cyclic loading
Prof. Subhamoy Bhattacharya

Day 2

09.00 – 10.30 Lecture 5: Soil Structure Interaction (Cyclic and dynamic)
Prof. Subhamoy Bhattacharya

10.30 – 11.00 Break

11.00 – 12.30 Lecture 6: Simplified hand calculation of case studies
Prof. Subhamoy Bhattacharya

12.30 – 13.30 Lunch

13:30-15:00 Lecture 7: Introduction to Bladed for offshore wind turbine and foundation modelling
Mr Alec Beardsell

15.00 – 15.30 Break

15:30-17:00 Lecture 8: Demonstration of offshore foundation load calculations in Bladed (ULS and FLS analysis)
Mr Alec Beardsell

Day 3
09.00 – 10.30 Lecture 9: Introduction and S – N Curve
Dr Helena Polezhayeva

10.30 – 10.45 Break

10.45 – 12.15 Lecture 10: Effect of Stress Concentration specific to offshore structures
Dr Helena Polezhayeva

12.15 -13.30 Lunch

13.30 – 15.00 Lecture 11: Rules for Fatigue design of Welded Structures, Effects of Random
Loads, Mean Stress, Thickness and Material Strength
Dr Helena Polezhayeva

15.00 – 15.30 Break

15.30 – 17.00 Lecture 12: Application of Fracture Mechanics and Post Weld Improvement Techniques Dr Helena Polezhayeva

Day 4

09.00 – 10.30 Lecture 13: Structural Reliability
Professor Purnendu Das

10.30 – 10.45 Break

10.45 – 12.15 Lecture 14: Structural Reliability Application to Foundation Design
Professor Purnendu Das

12.15 -13.30 Lunch

CV’S OF LECTURERS:

Prof Subhamoy Bhattacharya,Chair in Geomechanics, University of Surrey

Professor Subhamoy Bhattacharya currently holds the Chair in Geomechanics at the University of Surrey where he leads the Geomechanics Research Group. He is also the Programme Director for the MSc course in “Advanced Ground Engineering/Advanced Geotechnical Engineering” and the Director of Undergraduate Studies in Civil Engineering.  Previously, he held the post of Senior Lecturer at the University of Bristol, Departmental Lecturer at the University of Oxford and Academic fellowship at Tokyo Institute of Technology as well as industrial positions with Fugro Limited (UK) and Consulting Engineering Services (India) Ltd – now Jacobs. He obtained his PhD from the University of Cambridge, investigating failure mechanisms of pile-supported structures in liquefiable soils. He proposed a new theory on pile failure which received the 2005 T.K.Hseih award for the best paper in civil engineering dynamics from the Institution of Civil Engineers. His further work on piles includes design principles for the foundation design of new generation Floating Production Storage and Offloading platforms, built from his experience designing piles for more conventional offshore structures. His work on p-y curves for clay appears in the latest API/ANSI/ISO code of practice. His current research interest are foundations for offshore wind turbines, seismic behaviour of piles.

Some of his publications are:
Text Books
1. S.Bhattacharya (2019): Design of foundation for offshore Wind Turbines, Wiley. ISBN: 978-1-
119- 12812-0.
2. S.Bhattacharya, R.Orense and Lombardi (2018). Seismic design of foundations: Concepts and
Applications, ICE Publishing; ISBN:
9780727761668
3. S.Bhattacharya, N.Alexander, D.Lombardi and S.Ghosh (2015): Fundamentals of Engineering
Mathematics, ICE (Thomas Telford Publication).
ISBN: 9780727758415

Mr Alec Beardsell, DNVGL, UK

Alec Beardsell is a Senior Loads Analysis Engineer in the Turbine Engineering Support department of DNV GL Energy. His work involves using Bladed to perform load calculations and performance
assessments for wind turbine designers and manufacturers around the world. As well as
contributing to the design of onshore, offshore, floating and tidal turbines, he is engaged with turbine life extension projects, and turbulence modelling. Alec also regularly provides lectures, training material and resources to support undergraduate and masters level engineering courses at a range of universities including Oxford, Bristol, Cardiff and Cranfield. Alec holds a Masters degree in Physics from the University of Oxford and is a member of the Institute of Physics. He also has an MSc (with distinction) in Renewable Energy Systems Technology from Loughborough University, where he was awarded the Professor Leon Freris prize for his thesis on Non-Linear Wind Turbine Blade Modelling. Before working in engineering, Alec enjoyed a successful career in teaching. He has a PGCE from Cambridge University and has worked in four different schools in three different countries.

Dr Helena Polezhaeva, Consultant, France

Dr Helena has more than 30 years’ experience, and is internationally recognised as a fatigue expert,
specialising in the development of spectral fatigue analysis and fatigue assessment procedures for a wide variety of ship types and offshore structures.

Dr Helena also has expertise in fatigue related consultancy and research including fatigue testing and numerical analysis as well as the development and delivery of fatigue training. Helena was awarded a Royal Society Fellowship in 1994 for her PostDoctoral research

Professor Purnendu Das,
Director ASRANer Ltd, UK

Professor Purnendu Das BE, ME, PhD, C.Eng, C.MarEng, FRINA, FIStructE, FIMarEST has been the Director of ‘ASRANet from its inception in February 2006. He retired as Professor of Marine Structures in the Department of Naval Architecture & Marine Engineering at the University of Strathclyde, UK. Past EU projects were MARSTRUCT (a network of excellence on Marine Structure) and SHIPDISMANTL (a cost effective and environmentally friendly dismantling of ship structures). Past industrial projects included work from the UK Health and Safety Executive (HSE), MoD UK, Subsea-7 UK, Shell,
Wood group and US Navies etc. He was the principal investigator of many EPSRC projects. Before joining the University of Glasgow in 1991 he worked with British Maritime Technology as Principal Structural Engineer (1984-91). He is the author of more than 250 publications, including contract reports and more than 60 journal papers and was a member of the editorial boards of the ‘Journal of Marine Structures’, ‘Journal of Ship & Offshore Structures’, ‘Journal of Engineering under Uncertainty: Hazards, Assessment and Mitigation’ and ‘Journal of Ocean and Climate System’ amongst others. His areas of research include limit state design and analysis & reliability analysis of
ship & offshore structures. Professor Das has wide ranging industrial and academic contacts and has advised and supervised 20 PhD students, to his credit.
Details of visits and collaborations include his various sabbatical study periods spent at University of
California, Berkeley, USA (July – September 1996), at Lloyd’s Register of Shipping (August1997), Kockums Ltd (July 1998) and spent some time at Instituto Superior Técnico (IST), Lisbon
(July 2000). He has been running various successful CPD courses which are attracting many people from different industries. These courses are on ‘Fatigue & Fracture Analysis’, ‘Ships at Sea’, ‘Advanced Analysis and Design of Offshore Structures’, ‘Offshore Floating System Design’, ‘Structural Response under Fire and Blast Loading’ and ‘Design of Pipelines and Risers’
amongst others. He was a member of ISSC (International Ship and Offshore Structure Congress) for the periods of 1991-97 and 2003 – 2006. He was a member of the OMAE (Offshore Mechanics and Arctic Engineering) Organising Committee on ‘Safety and Reliability’. He has organised six ASRANet
International Conferences in 2002 (Glasgow), 2004 (Barcelona), 2006 (Glasgow), 2008 (Athens), 2010 (Edinburgh) and 2012 (London) where a large number of participants from various countries attended. The theme of the conference is the integration of risk, advanced structural analysis and structural reliability analysis as applicable to various engineering structures. He was the member of Research committee of the Institution of Structural Engineers (I.Struct.E) London for 3 years (2014-2017). He was a visiting professor at Wuhan University of Technology, China from July 2016-July 2019. At present he is a visiting professor at the University of Montenegro, Montenegro.

Content of the lectures:

Lecture 1: Overview of the whole Wind Turbine structure
General overview of the overall wind turbine structure/wind farm keeping in mind the concepts
necessary for foundation design.

Lecture 2: Loads on the offshore wind turbine structure
This lecture will focus on the main loads on the structure from wind, wave, 1P and 3P with the aim to obtain the mudline bending moment for foundation design. Also this lecture will describe a simple frequency domain methodology to obtain the critical loads (overturning mudline moment, lateral and vertical loads) in the foundation due to the 4 types of loads. An EXCEL example will be taken to show the methodology.

Lecture 3: Consideration for foundation design and the calculations necessary
The design consideration includes the following Limit States: ULS (Ultimate Limit State), SLS (Serviceability Limit State) and FLS (Fatigue Limit State). Issues related to installation will also be discussed. This section will also discuss the calculations that needs to be carried out the designers: (a) ultimate capacity of the foundation; (b) natural frequency of the whole system; (c) deflection and
rotation of the foundation; (d) long term tilting of the foundation and change in natural frequency.
Lecture 4: Geotechnical Site Investigation and Soil behaviour under cyclic loading This lecture will discuss the site investigation necessary and the soil testing required for obtaining the design
parameters for carrying out the design. The lecture will also discuss the advanced soil testing apparatus that may be used to obtain the parameters.

Lecture 5: Soil Structure Interaction (Cyclic and dynamic)

Explain the various Soil-Structure-Interaction and simplified methods that can be to carry out soil-structure analysis will be described. The analysis are: (a) Natural frequency of wind turbine structure considering the foundation flexibility based on a mathematical model; (b)
Minimum requirement of foundation stiffness (c) Prediction of rotational and tilting of the wind turbine; (d) Long term rotation prediction.

Lecture 6: Simplified hand calculation of case studies

This lecture will take an example of a wind turbine along with wind, wave and geotechnical data to carry out step by step calculations.

Lecture 7: Introduction to Bladed offshore wind turbine
and foundation modelling

This lecture will provide a general overview of the aeroservo-hydro-elastic software Bladed and the different engineering models behind the code in order to represent the coupled dynamics of offshore wind systems. Special focus will be given to the offshore aspects of it, covering both the metocean environmental conditions and offshore foundation modelling. An overview of the different links with other engineering codes for offshore design will also be provided such as Sesam, Ansys Asas and Sacs.

Lecture 8: Demonstration of offshore foundation load calculations in Bladed (ULS and FLS analysis)

A practical demonstration will be shown for the typical load calculations workflow in Bladed in order to compute both ultimate and fatigue loads for offshore foundations, from turbine/foundation/soil inputs up to postprocessing the loads results.

Lecture 9: Introduction and S-N Curve

Fatigue mechanism of materials Fatigue mechanism of welded structures Fatigue design principles Fatigue damage models Uncertainties in fatigue damage prediction Major factors affecting fatigue life Origin of SN curve & Fatigue test Segments of SN curve SN curve for welded structural details

Lecture 10: Effect of Stress Concentration
Introduction and lessons learned from the past Definition of stress concentration factor (SCF) Methods for assessing SCF Stress concentration in hull structural details Stress concentration at welds Finite element modelling for SCF

Lecture 11: Rules for Fatigue design of Welded Structures

Fatigue assessment process for hull and offshore structures Assessment of local stress in structural details for fatigue analysis Evaluation of hot-spot stress Secondary stress Design SN curve Strain-Life Criterionbased Approach Basics and Application Local Strain Methodology Strain Life Cyclic Curves Strain-Life Criterion for Fatigue Evaluation of Local Strain Applications

Lecture 12: Application of Fracture Mechanics and Post Weld Imporvement
Fracture Mechanics: Basic concepts Fatigue crack propagation Stress intensity factor evaluation of stress intensities, Evaluation of (residual) fatigue life, Fatigue crack propagation: Consequences Welding Improvement Techniques Loading and Environmental Conditions Limitations

Lecture 13: Structural Reliability
Uncertainties, Nature of Uncertainties, Various Reliability Analysis techniques; FORM, SORM etc.

Lecture 14: Structural Reliability Application To Foundation Design
Septi margin equations for ULS, FLS & SLS

Duration: 4 Days

Cost: £1,495 + VAT

Foundation Design of Offshore Wind Turbine Structures Training in London, Scotland,  Inverness, Aberdeen, Glasgow, Edinburgh, Dunfermline and other sites throughout the UK including onsite closed company courses are available.