Wind Energy Research at AAU- with focus on composite materials

and wind turbine blades

Presented by Erik Lund, Professor in Computational Mechanics and Design OptimizationDepartment of Mechanical and Manufacturing Engineering,

www.m-tech.aau.dk,Aalborg University

Agenda:• Overview of AAU and activities within wind energy• Focus on wind turbine blades / composite materials

June 19, 2012, NOVI

Aalborg University• Aalborg University has more than 17,000 students, ranging from students

at preparatory courses through doctoral-level candidates

• Around 4,000 students are enrolled at the Faculty of Humanities, 5,000 students at the Faculty of Social Sciences, 7,000 at the Faculty of Engineering and Science and 1000 students at Faculty of Medicine

• 10% are international students from 100 different countries all over the world

• The university employs around 1300 faculty and 1000 administrative staff

• The research are organized into 4 faculties and 18 departments

• Aalborg University offer in total 65 different educational programmes organized in 10 schools

• Aalborg University have more than 60 master programmes taught in English

Campus Locations in DK

Aalborg University – Campus Aalborg

Aalborg University – Campus Aalborg East

Revenue : 1.30 bill dkr

Employees : +1300

Brutto area 140000 m2• Research 75000 m2

• Education 55000 m2

• Administration 2500 m2

• Other 7500 m2

Departments : 10

Schools : 3 (Appr. 30 Bachelor, 60 Master programmes - English)

Ph.D. : 500

Students : 7000

Key figures 2011 (Engineering and Science)

437

331

12029

41

342

Revenue budget 2011 - 1300 mio. dkr.(in whole mill dkr.)

Education (34%)

Research (25%)

Ph.D/research education(9%)

Public sector consultancy(2%)

Sale of goods and services(3%)

External funded research(26%)

Departments – Engineering and ScienceCivil Engineering Mathematics and Statistics

Architecture, Media and Design Computer Science

Mechanical Engineering and Manufacturing

Physics and Nano-technology

Energy Technology

Electronic Systems Learning and Philosophy (cross faculty)

Chemistry, Biotech and Life Science Center for Industrial Production

Planning Campus Esbjerg

Campus Copenhagen

Aalborg University - EXCELLENCE in wind energy

Research areas in wind energy:

Power electronics, GeneratorsPower systems, Grid integrationControlBlades, Composite materials and structuresSupport structures / FoundationStructural dynamicsOffshore and on-shore wind turbinesReliability / Operation & MaintenanceLogistics, production and design for manufacturing of wind turbinesEnergy planning

Aalborg University - EXCELLENCE in wind energy

Research projects – focus on cooperation with industry and international partners - Examples:

• AEOLUS: Distributed Control of Large�Scale Offshore Wind Farms

• Development of a secure, economic and environmentally-friendly modern power system

• Dynamic wind turbine model - from wind to grid

• Foundation of offshore wind turbines with suction buckets

• Blade King

• Composite shell foundations made of high-tension concrete and steel sheets

• Reliability-based analysis applied for reduction of cost of energy for offshore wind turbines

• Norwegian Centre for Offshore Wind Energy (NORCOWE)

• Vestas Power Programme

Aalborg University - Excellence in wind energy

MSc programs :Wind Power Systems (electrical aspects)

Offshore, Structural and Mechanical Engineering (mechanical aspects)

Energy Planning and Sustainable Energy

Continuing education:Master in wind energy: WindMaster

PhD programs:More than 70 PhD students

PhD courses

Wind Energy - Aalborg University - Departments

• Department of Civil Engineering• Department of Development and Planning• Department of Energy Technology• Department of Electronic Systems

- Section for Automation & Control• Department of Computer Science• Department of Mechanical and Manufacturing Engineering

Number of Ph.D students within Wind energy

DepartmentsActive Ph.D.students

Civil Engineering 14Mechanical and Manufacturing Engineering 16

Electronic Systems 18

Energy Technology 25

Planning 2

Total 75

Department of Civil Engineering

Wind energy activities:• Loads and safety – Operation and Maintenance• Rotordynamics• Foundations – substructure design• Wave and current loads - scour• See more details on the following slides

• Professor John Dalsgaard Sørensen• Professor Søren R.K. Nielsen• Assoc. Prof. Peter Frigaard• Professor Lars Bo Ibsen• Assoc. Prof. Lars Andersen

Load & Safety – Operation & MaintenanceReliability of wind turbinesPlanning of operation & maintenance

• Professor John Dalsgaard Sørensen – jds@civil.aau.dk

RotordynamicsMulti-body dynamics of wind turbinesNon-linear rotor dynamicsSmart control

• Professor Søren R.K. Nielsen – srkn@civil.aau.dk

Wave and current loads - Scour

•Loads from wave/current

•Loads from ice

•Erosion holes (Scour)

•Scour protection• Assoc. Prof. Peter Frigaard – pf@civil.aau.dk• Assoc. Prof. Thomas L Andersen – tla@civil.aau.dk

Environmental offshore loads:

•Waves; irregular breaking

•Currents; wave generated / tidal

Foundation Substructures and GeotechnicsMono-pile and jacket foundation for offshore wind turbinesBucket foundation for offshore wind-turbinesSoil - Structure interaction of foundations for wind turbines

• Professor Lars Bo Ibsen – lbi@civil.aau.dk• Assoc. Prof. Lars Andersen – la@civil.aau.dk

Offshore wind energy- project examples:UpWind: Integrated Wind turbine DesignEU 6 rammeprogram: 2006-2011John D Sørensen, Institut for Byggeri og AnlægZhe Chen & Birgitte Bak-Jensen, Institut for Energiteknik

Development of the Bucket foundationLars Bo Ibsen, Institut for Byggeri og AnlægSøren A. Nielsen, MBD

Physical and numerical modeling of monopile in silt with focus on offshore wind turbines

Lars Bo Ibsen, Institut for Byggeri og AnlægSøren A. Nielsen, MBD

Offshore wind energy- project examples:

Time Development of Scour Around Offshore MonopilesSamfinansieret PhD project 2008-2011Peter Frigaard, Institut for Byggeri og Anlæg

Wave Forces on Boat LandingsSamfinansieret PhD projekt 2008-2011Lars Bo Ibsen & Thomas Lykke Andersen, Institut for Byggeri og Anlæg

Probabilistic Design of Wind TurbinesDet Strategiske Forskningsråd 2007-2010John D Sørensen, Institut for Byggeri og Anlæg

Offshore wind energy- project examples:Reliability-based analysis applied for reduction of cost of energy for offshore

wind turbinesDanish Council for Strategic Research (DSF) 2009-2013John D Sørensen, Lars Bo Ibsen, Lars Andersen, Institut for Byggeri og AnlægOle Thybo Thomsen and Erik Lund, Institut for Mekanik og Produktion

Norwegian Centre for Offshore Wind Energy (NORCOWE)Norwegian Council for Strategic Research 2009-2016Zhe Chen, Frede Blaabjerg, Institut for EnergiteknikThomas Bak, Institut for Elektroniske SystemerJohn D Sørensen, Institut for Byggeri og Anlæg

Department of Development and Planning Wind energy activities:• Inter-disciplinary work on energy planning• Technical energy systems analyses and GIS analyses of energy systems• Primary focus is on the production of energy

• Professor Henrik Lund• Assoc. Professor Poul A Østergaard

Department of Electronic Systems- Section for Automation & Control

Wind energy activities:• Control of wind turbines• Control of floating wind turbine installations (NORCOWE)• Distributed Control of Large�Scale Offshore Wind Farms (AEOLUS):

• Professor Thomas Bak• Professor Jakob Stoustrup• Professor Rafal Wisniewski

Department of Energy

Wind energy activities:• Energy production, distribution, consumption, and control• Vestas Wind Power Program• Grid Integration of Offshore Wind Farms (NORCOWE)• Many other examples, see a few on the following slides

• Professor Frede Blåbjerg• Professor Zhe Chen• Professor Remus Teodorescu• Professor Stig Munk-Nielsen• Assoc. Prof. Birgitte Bak-Jensen

Rotor Gearbox GeneratorPowerelectronics Transformer Grid

MechanicalEnergy

ElectricalEnergy

Grid Requirements!

Control System

Wind Energy

Key Words:

• Power Electronics converters• Modern Generators• Fluid power System• New Systems Concepts• Advanced Control• Grid Connection• HVDC transmision• Wind farms• Grid Codes• Reliability• Systems optimization• Performance & cost

Wind Turbine Systems

Key Words:

• Distributed Power• Renewable Sources• New Grid Structures• Grid Stability• Grid Reliability• Grid Control• Grid Components• Independency• Micro Grids• Self Organised Networks• Storage Systems

EU UNIFLEX-PM

Smart Grid and Active Networks

Next: Department of Mechanical and Manufacturing Engineering

• Approx. 110 faculty/supporting staff/PhD students• Budget 2011: Approx. DKK 90 mill.• Key professional areas:

o Materials Science and Engineering (composites, polymers, ceramics, metals and alloys)

o Mechanics / Solid mechanics / Structural mechanics (lightweight structures, composites, …)

o Computational Mechanics & Computer-Aided Engineering Design (FE analysis, multi-criteria optimization, fluid structure interaction, acoustics, …)

o Biomechanics (musculoskeletal modelling & ergonomics)o Manufacturing Engineering (processing technology, metals, polymers, welding,

assembly, automation, …)o Robotics and Mechatronicso Management, operational analysis, logistics and production planning

Department of Mechanical and Manufacturing Engineering (M-Tech)(Merger of Department of Mechanical Engineering and Department of Production per 1 March 2010)

M-Tech research groups

1. Materials Science and Engineering2. Solid and Computational Mechanics3. Mechanical Systems and Mechatronics4. Biomechanics - The AnyBody Research Group5. Materials Processing Group6. Robotics and Automation7. Applied Operations Research & Operations Management8. Logistics - Centre for Logistics (CELOG)9. Product Configuration10. Construction Management

At the moment all research activities related to wind energy are in the first two research groups listed.

Materials Science and Engineering

Key areas of research:• Mechanics of materials• Mesomechanics• Polymers :

characterization and processing

• Polymer basedcomposites

• Nano phased/structuredmaterials (nanocomposites)

• Metal alloys• Ceramics and

microcellular materials

Solid and Computational MechanicsKey areas of research:• Fundamental mechanics and solid mechanics• Machine design (transmissions, bearings, …)• Dynamics and fluid structure interactions• Finite element analysis and other numerical

methods• Computer-aided engineering design• Multidisciplinary design optimisation• Vibro acoustics• Experimental characterisation of materials and

structures• Fibre reinforced polymer materials (FRP or

”composites”)• Lightweigth composite and sandwich structures• Processing/manufacturing of polymer composites

Laboratories & Workshops

• Well-equipped laboratories and workshops

• Integrated part of the education, research and development activities

• Materials testing and characterisation

• Testing of structures and mechanical systems

• Prototype development and qualification

Laboratories & Workshops – from Autumn 2012

Our laboratories and workshops are being completely refurbished for 70 mill DKK. Opening in September 2012.

All facilities are moved to Fibigerstraede 14 which has been expanded.

State-of-the-art laboratories and workshops within mechanical and manufacturing engineering.

Materials Science and Engineering / Solid and Computational Mechanics

Staff:• 14 faculty members (professors, assoc. professors, assist. professors)• 25 PhD students (including 10 industrial PhD students) – 16 associated

with wind energy• 8 postdocs

Project portfolio on polymers, composite materials and structures(most projects related to wind turbine industry):

• Total project turnover in excess of EURO 15 mill.• More than 15 ongoing research projects with Siemens Wind Power,

Vestas Wind Systems, LM Wind Power and Suzlon Wind Energy

Activities related to Wind Power TechnologyTeaching/education:

• Student projects – typically 2nd, 3rd and 4th semester M.Sc. Curriculum: Vestas Wind Systems, LM Glasfiber, Siemens Wind Power, Suzlon Wind Energy … (typically 3-6 M.Sc. projects every yearrelated to wind power technology)

• Ad hoq courses and supervision of projects for industry

Research:• Mainly related to characterisation, modelling/analysis, design and

optimization of advanced composite materials and sandwich structures for wind turbine blades

• A few projects concern modelling, design and validation of mechanical drive trains for wind turbines including gears and bearingswith a special focus on wear and tribology.

• Several ongoing and recent projects with partners in wind energysector (wind turbine blade manufacturers, material suppliers, research institutions, … )

Projects within Wind Energy

Ongoing large research projects (+50 mill. kr):

• HTF platform (2008-2013) ”Blade King” – with LM Wind Power, Comfil ApS & DTU Wind Energy.(HTF: Højteknologifonden – Advanced Technology Foundation)

• Large-scale integration project under EU-FP7 (FP7-NMP-2007-2.1-1, Grant agreement no.: 214148): “NanCore - Microcellular Nanocomposite for Substitution of Balsa Wood and PVC Core Materials”. Many partners including LM Wind Power.

• DSF project (2010-2017): “Danish Centre for Composite Structures and Materials for Wind Turbines” – with DTU, AAU, LM Wind Power, Siemens Wind Power, …DSF: Danish Council for Strategic Research.Nearly all key persons from Danish Universities working on composite materials and structures for wind turbines are involved in this center.AAU will have 7 Ph.D. students in relation to this center.

Projects within Wind EnergyExamples of ongoing projects funded by FTP – (the Danish Council for

Technology and Innovation) and DSF:

• FTP (2011-2014): “Optimal Design of Composite Structures under Manufacturing Constraints“ - with DTU Wind Energy and Siemens Wind Power.

• FTP (2011-2014): “Thermal Degradation Effects in Foam Cored Sandwich Structures” –with LM Wind Power, DIAB AB, and Univ. Southampton.

• FTP (2011-2014): “Enhanced Performance of Sandwich Structures by Improved Damage Tolerance” – with DTU-MEK, Siemens Wind Power, LM Wind Power, and Univ. Southampton.

• FTP (2010-2013): “Mechanical Property Characterisation of Fibre Composites with Focus on Thermal Cure Conditions” - with L´Ecole Polytechnique Montreal, Canada, and Siemens Wind Power.

• DSF (2009-2013): “Reliability-Based Analysis and Design of Wind Turbine Blades” –with AAU-CIVIL, Vestas Wind Systems, DONG, and DTU Wind Energy.

Ongoing Industrial Ph.D. Projects within Wind Energy

• 2008-2012: “The Influence of Defects on the Failure of Wind Turbine Blades”. Industrial Ph.D. project with Siemens Wind Power.

• 2011-2014: “Progressive Damage Simulation of Laminates in Wind Turbine Blades under Quasistatic and Cyclic Loading”. Industrial Ph.D. project with Siemens Wind Power.

• 2011-2014: “Design of Sandwich Structures with Grid Scored Core Materials for Wind Turbine Blades”. Industrial Ph.D. project with Suzlon Wind Energy.

• 2008-2011: “Dynamic Drive Train Simulation”. Industrial Ph.D. project with VestasWind Systems.

• 2009-2012: “Optimal Design of Wind Turbine Drive Trains”. Industrial Ph.D. project with Vestas Wind Systems.

• 2009-2012: “ Development of a New Hydraulic Yaw System for Wind Turbines”. Industrial Ph.D. project with Liftra Aps.

More information

Prof. Ole Thybo Thomsen, ott@m-tech.aau.dkProf. Ryszard Pyrz, rp@m-tech.aau.dkProf. Erik Lund, el@m-tech.aau.dk

On the following slides one example of a research project on wind turbine blades is presented.

“Structural Instability Phenomena in Wind Turbine Blades”“Improved design of large wind turbine blades” – 2004-2010 EUDP 3&4: AAU, Risø-DTU, DTU, Vestas Wind Systems and LM Glasfiber

The test data, post mortem analysis and "standard" FE models suggested:• Local buckling phenomenon and influence of initial geometric imperfections• Local stiffness degradation, i.e. damage propagation (delamination) - probably

interlaminar/delamination damage at biaxial interfaces• Very difficult to capture and explain the sequence of events causing the progressive

failure

Courtesy of Vestas Wind Systems A/S

• A method for progressive damage simulation of composite structures was developed, taking both geometric and material nonlinearities into account

• Adaptive ”mesh” refinement and cohesive zone modeling (large scale) • Progressive development of debonding/delamination (damage) and local

”instabilities”

• A method for progressive damage simulation of composite structures was developed, taking both geometric and material nonlinearities into account

• Adaptive ”mesh” refinement and cohesive zone modeling (large scale) • Progressive development of debonding/delamination (damage) and local

”instabilities”

Comparison between measured acoustic emission data (a) and finite elementdamage results (c)

A look inside the deformed main spar:(a) damage state 1 prior to the limit point and figure (b) damage state 2 after the crossing of the limit point.

More information

Prof. Erik Lund, el@m-tech.aau.dkDepartment of Mechanical and Manufacturing Engineering, AAU