mkessler@iastate.edu

Publish in

Documents

6 views

Please download to get full document.

View again

of 28
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Share
Description
Composite Materials for Wind Turbine Blades Wind Energy Science, Engineering, and Policy (WESEP) Research Experience for Undergraduates (REU) Michael Kessler Materials Science & Engineering. mkessler@iastate.edu. Outline. Background
Transcript
Composite Materials for Wind Turbine BladesWind Energy Science, Engineering, and Policy (WESEP) Research Experience for Undergraduates (REU)Michael Kessler Materials Science & Engineeringmkessler@iastate.eduOutline
  • Background
  • Introduction of Research Group at ISU
  • Motivation for Structural Composites
  • Description of Carbon Fibers for Wind Project
  • Material Requirements for Turbine Blades
  • Composite Materials
  • Fibers
  • Matrix
  • Properties
  • Polymer Composites Research Grouphttp://mse.iastate.edu/polycomp/mkessler@iastate.edu
  • Funding:
  • Army Research Office (ARO)
  • Air Force Office of Scientific Research (AFOSR)
  • Strategic Environmental Research and Development Program (SERDP)
  • National Science Foundation (NSF)
  • IAWIND – Iowa Power Fund
  • NASA
  • Petroleum Research Fund
  • Grow Iowa Values Fund
  • Plant Sciences Institute
  • Consortium for Plant Technology Research (CPBR)
  • Motivation – Structural CompositesPercentage of composite components in commercial aircraft*
  • Why PMCs?
  • Specific Strength and Stiffness
  • Part reduction
  • Multifunctional
  • *Source: “Going to Extremes” National Academies Research Council Report, 2005Advanced Carbon Fibers From Lignin for Wind Turbine ApplicationsPI: Michael R. Kessler, Department of Materials Science and Engr., Co-PI: David Grewell, Department of Ag. and Biosystems Engr.,Iowa State UniversityIndustry Partner:Siemens Energy, Inc., Fort Madison, IA20 % Wind Energy Scenario300 GW of wind energy production by 2030
  • Keys for achieving 20% scenario
  • Increasing capacity of wind turbines
  • Developing lightweight and low cost turbine blades (Blade weight proportional to cube of length)
  • Materials For Turbine Blades
  • Fiber reinforced polymers (FRPs) are widely used for blades
  • Lightweight
  • Excellent mechanical properties
  • Commonly used fiber reinforcements are glass and carbon
  • Glass Fiber vs. Carbon Fiber
  • Glass Fiber
  • Adequate Strength
  • High failure strain
  • High density
  • Low cost
  • Carbon Fiber
  • Superior mechanical properties
  • Low density
  • High cost (produced from PAN)
  • Lignin- A Natural Polymer
  • Lignin, an aromatic biopolymer, is readily derived from plants and wood
  • The cost of lignin is only $0.11/kg
  • Available as a byproduct from wood pulping and ethanol fuel production
  • Can decrease carbon fiber production costs by up to 49 %.
  • Current applications for lignin use only 2% of total lignin produced
  • Carbon Fibers from Lignin
  • Production steps involve
  • Fiber spinning
  • Thermostabilization
  • Carbonization
  • Current Challenges
  • Poor spinnability of lignin
  • Presence of impurities
  • Choice of polymer blending agent
  • Compatibility between fibers and resins
  • Warren C.D. et.al. SAMPE Journal 2009 45, 24-36Project Goals
  • Develop robust process for manufacturing carbon fibers from lignin/polymer blend
  • Evaluate polymers for blending, including polymers from natural sources
  • Optimize lignin/polymer blends to ensure ease of processability and excellent mechanical properties
  • Investigate surface functionalization strategies to facilitate compatibility with polymer resins used for composites
  • Technical Approach
  • Evaluate and pretreat high purity grade lignin
  • Spin fibers from lignin-copolymer blends using unique fiber spinning facility
  • Characterize surface and mechanical properties of carbon fibers made from lignin precursor
  • Perform fiber surface treatments (silanes and alternative sizing agents)
  • Evaluate performance for a prototype coupon (Merit Index)
  • Outline
  • Background
  • Introduction of Research Group at ISU
  • Motivation for Structural Composites
  • Description of Carbon Fibers for Wind Project
  • Material Requirements for Turbine Blades
  • Composite Materials
  • Fibers
  • Matrix
  • Properties
  • Material Requirements
  • High material stiffness is needed to maintain optimal aerodynamic performance,
  • Low density is needed to reduce gravitaty forces and improve efficiency,
  • Long-fatigue life is needed to reduce material degradation – 20 year life = 108-109 cycles.
  • Fatigue
  • First MW scale wind turbine
  • Smith-Putnam wind turbine, installed 1941 in Vermont
  • 53 meter rotor with two massive steel blades
  • Mass caused large bending stresses in blade root
  • Fatigue failure after only a few hundred hours of intermittent operation.
  • Fatigue failure is a critical design consideration for large wind turbines.
  • Material RequirementsMb=0.003Mb=0.006Merit index for beam deflection (minimize mass for a given deflection)Absolute Stiffness (~10-20 Gpa)Resistance against fatigue loads requires a high fracture toughness per unit density, eliminating ceramics and leaving candidate materials as wood and composites.Terminology• Composites: --Multiphase material w/significant proportions of ea. phase.• Matrix: --The continuous phase --Purpose is to: transfer stress to other phases protect phases from environment
  • • Dispersed phase:
  • --Purpose: enhance matrix properties.
  • increase E, sy, TS, creep resist.
  • --For structural polymers these are typically fibers
  • --Why are we using fibers?
  • For brittle materials, the fracture strength of a small part is usually greater than that of a large component (smaller volume=fewer flaws=fewer big flaws).
  • Outline
  • Background
  • Introduction of Research Group at ISU
  • Motivation for Structural Composites
  • Description of Carbon Fibers for Wind Project
  • Material Requirements for Turbine Blades
  • Composite Materials
  • Fibers
  • Matrix
  • Properties
  • Cross-section of Composite BladeMaterial for Rotorblades
  • Fibers
  • Glass
  • Carbon
  • Others
  • Polymer Matrix
  • Unsaturated Polyesters and Vinyl Esters
  • Epoxies
  • Other
  • Composite Materials
  • D. Hull and T.W. Clyne, An Introduction to Composite Materials, 2nd ed., Cambridge University Press, New York, 1996, Fig. 3.6, p. 47.Fibers
  • Most widely used for turbine blades
  • Cheapest
  • Best performance
  • Expensive
  • Composite properties from various fibersUnsaturated Polyesters
  • Linear polyester with C=C bonds in backbone that is crosslinked with comonomers such as styrene or methacrylates.
  • Polymerized by free radical initiators
  • Fiberglass composites
  • Large quantities
  • Epoxies
  • Common Epoxy Resins
  • Bisphenol A-epichlorohydrin (DGEBA)
  • Epoxy-Novolac resins
  • Epoxide Group
  • Cycloaliphaticepoxides
  • Tetrafunctionalepoxides
  • Epoxies (cont’d)
  • Common Epoxy Hardners
  • Aliphatic amines
  • Aromatic amines
  • Acid anhydrides
  • DETAHexahydrophthalic anhydride (HHPA)M-Phenylenediamine (mPDA)Step Growth Gelation
  • Thermoset cure starting with two part monomer.
  • Proceeding by linear growth and branching.
  • Continuing with formation of gell but incompletely cured.
  • Ending with a Fully cured polymer network.
  • From Prime, B., 1997Composite Materials
  • Resin and fiber are combined to form composite material.
  • Material properties depend strongly on
  • Properties of fiber
  • Properties of polymer matrix
  • Fiber architecture
  • Volume fraction
  • Processing route
  • From Prime, B., 1997Properties of Composite Materials
  • Stiffness
  • Static strength
  • Fatigue properties
  • Damage Tolerance
  • References
  • Brondsted et al. “Composite Materials for Wind Power Turbine Blades,” Annu. Rev. Mater. Res., 35, 2005, 505-538.
  • Brondsted et al. “Wind rotor blade materials technology,” European Sustainable Energy Review, 2, 2008, 36-41.
  • Hayman et al. “Materials Challenges in Present and Future Wind Energy,” MRS Bulletin, 33, 2008, 343-353.
  • We Need Your Support
    Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

    Thanks to everyone for your continued support.

    No, Thanks