Bio-based Materials for Large Wind Turbine Blades Prepared for: Massachusetts Wind Working Group September 30th, 2015 Rachel Koh Ph.D. Candidate, Univ...
Bio-based Materials for Large Wind Turbine Blades Prepared for: Massachusetts Wind Working Group September 30th, 2015 Rachel Koh Ph.D. Candidate, University of Massachusetts Amherst Advisors: Peggi Clouston, Bob Hyers, Matt Lackner
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Motivation for Large Wind Energy 4.13% of US electricity generated by wind in 2013 30% of all new generating capacity from 2009-2014
1 𝑃 = 𝜌𝐴𝑉 3 2
Wind turbine rotor size trends from Fichaux (2011), DTU-Riso
Density • influences strength requirement Hull, MA municipal wind turbine photo: R. Koh
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Concerns with fiberglass and carbon fiber Fiberglass • mass scaling • recyclability / end-of-life disposal options • global production increase from 5.9 million metric tons in 1999 to 8.7 million in 2011 • ~10% global fiberglass market share for wind energy and increasing
Blade Mass Scaling Relationships from NREL Cost and Scaling Model
Carbon fiber • expensive • brittle • energy intensive production Koh 2015
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Advantages of Bio-Based Materials Competitive specific stiffness and strength Competitive fatigue properties Ashby chart for Plant Fiber Reinforced Polymers from Shah (2013) at Oxford U.
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Advantages of Bio-Based Materials (cont’d) Renewable (unlimited resource) Biodegradable when triggered Low emissions manufacturing • EU- Directive on Landfill of Waste and End-of-life Vehicle Directive are seen as barriers for development and continued use of glass and carbon in some markets
Low cost raw materials “Bio-inspired” and “Biomimicry” engineering
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Challenges with Bio-Based Materials Variable mechanical properties Limited experimental data for complex loading conditions such as off-axis and multiaxial loading High sensitivity to moisture Not fully developed manufacturing processes
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Current Projects Shear Properties and Failure Mechanics of AnglePly Wood Laminate Beams Yield Criteria Assessment for Multiaxial Wood Laminate and Flax Fiber Reinforced Composites FEA of Wind Turbine Blades with Material Property Variability using Probabilistic Design
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Shear Properties and Failure Mechanics of Angle-Ply Wood Laminate Beams
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Multidirectional Materials in Wind Turbine Blades
Adapted from Gurit Corporation (2014).
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Torsion Test for Shear Strength and Stiffness
Adapted with permission from Yang (2012).
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Torsion Test Configuration (ASTM D198)
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Preliminary Torsion Test Results Torsion Test Results angle-ply unidirectional
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Torque (N-m)
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20 25 30 Twist (degrees)
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Possible failure modes under torsional loading
rolling shear failure
(𝜏𝑧𝑥 )
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(𝜏𝑦𝑥 )
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Yield Criteria Assessment for Multiaxial Wood Laminate and Flax Fiber Reinforced Composites
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Multidirectional Materials in Wind Turbine Blades
Adapted with permission from Gurit Corporation (2014).
Preliminary Results (cont’d) Biaxial Failure Envelopes for Several Composite Failure Criteria 2.5 Tension Tests Compression Tests Tsai-Wu Tsai-Hill Hoffman Chamis
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Future Tasks multiaxial flax composite tests develop finite element material model to reflect multiaxial test data finite element design of hybrid bio-based 5MW blades
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Acknowledgements Committee: Professor Bob Hyers (MIE), Assoc. Professor Peggi Clouston (ECO), Assoc. Professor Matt Lackner (MIE), Adjunct Faculty John Fabel (ECO) Undergraduate Students: Alex Finn (MIE ‘14), Jesse Turek (BCT ‘14), Charlie Tormanen (BCT ‘15), Malia Charter (Smith College ’16), Melody Cao (Smith College ‘16), Yashira Valentín Feliciano (University of Puerto Rico) Funding source: NSF Offshore Wind Energy IGERT Grant Number 1068864
