Blade with Shear Web bonded to Spar Cap Sandwich Shell TE Shear Web LE Shear Web Trailing Edge...
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Transcript of Blade with Shear Web bonded to Spar Cap Sandwich Shell TE Shear Web LE Shear Web Trailing Edge...
Blade with Shear Web bonded to Spar Cap
Sandwich Shell
TE Shear Web
LE Shear Web
Trailing Edge
Sandwich Shell
Sandwich Shell
Sandwich Shell
Lower (HP) Spar Cap
Upper (LP) Spar Cap
2
Leading Edge
Source:http://www.compositesworld.com/articles/wind-blade-manufacturing-targeting-cost-efficiency-through-materials-based-strategies.aspx 4/5/2009
Blade Objectives
Figure from GE
Blade Objectives
• Maximize annual energy yield• (limit maximum power)• Resist extreme and fatigue loads• Restrict tip deflections• Avoid resonances• Minimize weight and cost
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
UTS UCS UCS/sg Fatique % of UCS
Stiffness/sg
E/UCS^2
Glass/X 880 720 390 19 20 .07
Glass/polyester
700 580 310 21 18 .1
Carbon/epoxy
1830 1100 700 32 90 .12
Birch/epoxy
117 81 121 20 22 2.3
Steel: fatigue and mfgblty
Blade Materials
• compressive strength-to-weight ratio,• fatigue strength as a percentage of
compressive strength,• stiffness-to-weight ratio,• a panel stability parameter, E/(UCS)2.
April 18, 2023 8Courtesy: Nolet, TPI
Power, Length and Weight
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
Polymer Matrix Composites & Processes
General Composite Information
• Composites: 2 or more physically distinct phases
• Properties are better than the constituents
• High strength to weight ratio• Also. . Corrosion, fatigue, toughness, surface
finish
Why nots . . .
• (many have) anisotropic properties• Polymer based may be subject to chemical
attack• Cost?• Manufacturing process often slow and costly
(Groover p 177)
2 or more phases
• Matrix (primary phase)– Polymer, metal, or ceramic
• Reinforcing agent (imbedded phase)– Polymer, metal, ceramic, or element– Fibers, particles, . . .
Possible combinations for 2 phases
Fiber reinforcement
• Diameters of 0.0001 to 0.005 inches• As D ↓, orientation ↑, probability of defect↓– tensile strength↑ ↑
• Orientation:– Unidirectional, planar, 3 dimensional
Fiber Reinforced Polymer Composites
• Short fibers:– Open mold: spray up– Closed mold processes
• Long fibers:– Open mold: hand, automated tape machines– Closed mold– Filament winding– Pultrusion
Materials
• Polymer matrix– Thermosets: most common– Thermoplastics
• Reinforcing– Glass– Carbon– Kevlar (polymer)
Composing Composites . . .
• Molding compounds– Mix short fibers and matrix
• Prepegs– Fibers impregnated with partially cured TS matrix– Allows fibers to ‘stay put’– Continuous fibers
• Or done in the mold
Open Mold Process
• Spray up– Requires mold– Discontinuous fibers // random orientation– Mixture of fiber and matrix deposited in mold
• Automated tape laying machine– Requires mold– Requires use of prepeg– CNC control
Image sources: http://www.bauteck.com/manufacture/Manufacture2.htm 4/5/9 http://www.mmsonline.com/articles/getting-to-know-black-aluminum.aspx 4/5/9
Filament Winding• Wound around mandrel or part of final
component• Continuous fibers– Matrix added before or after winding
• Automation controls wrap pattern
Source:http://sacomposite.com/filament_winding_carbon_fiber.html 4/5/9
Pultrusion
• Continuous fibers• Dipped into matrix • 2 options:– Pulled through die and cured– Laid up into an open mold (and later cured)
Source: http://www.ale.nl/ale/data/images/Pultrusion.jpeg 4/5/9
http://www.tangram.co.uk/TI-Polymer-Pultrusion.html
Open Mold Processes
• Hand lay up– Oldest, labor intensive– Mold required– Fibers placed in mold:• Dry fibers placed and then matrix added
– Pour or brush or spray >> rolled to achieve mixture– Vacuum used to ‘pull’ matrix into fiber
• Prepeg placed in mold
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
Source: www.tpicomposites.com 3/2008
Source: www.tpicomposites.com 3/2008
Source: www.tpicomposites.com 3/2008
Reusable Silicon Bag Technology for SCRIMP®
April 18, 2023 28
o Silicone bags are rapidly fitted to the infusion toolo Feed lines, vacuum lines and embossed distribution channels are integrated into the bag improving the repeatability of the process (TPI Patented Technology)
Courtesy: Nolet, TPI
Fibers• Woven Fabrics– Higher cost, less applicable as
structural components for blades
• Non-woven Multiaxials– Most widely used in VARTM processes– Low-cost, non-crimp form results in
superior performance– “Uni-directional”, Biaxial, Double Bias,
Triaxial and Quadraxial material forms available.
April 18, 2023 29
Courtesy of Saertex USA
Courtesy: Nolet, TPI
Resin Matrices
• Epoxies remain a primary resin of use in European based blade designs
• Vinyl-esters are attracting much interest by blade designers
• Polyester resins are still prominent in the industry.
• Thermoplastics and other matrices
April 18, 2023 30Courtesy: Nolet, TPI
http://www.compositesworld.com/articles/carbon-fiber-in-the-wind.aspx
Blade Components
Infused Together• Skin
– Composite– Core
• Spar cap– Composite
• Shear web– Composite– Core
• Root Section– composite
Other Materials• Bond paste• Hardware• Balance box• Paint• Lightening protection
system• Platform
Quality Issues
• Waves– Aspect ratio (L/a)
• Bond failure• Dry infusion• Lack of continuous fibers• Geometrical errors• Fabric assembly errors
Figures from: “Yerramalli, Miebach, Chandraseker, Quek: “Fiber Waviness Induced Strength Knockdowns in Composite Materials Used in Wind Turbine Blades”. 2010
Process Steps• Cut fabric• Preforms
– Layup– Infuse– Inspect– Trim
• Shell– Layup– Install preforms– Infuse
• Assembly– Shear web– 2 shells
• Finishing– Finish edges– Wet layup
• Final cure• Drill and cut end square• Finishing and painting• Hardware• Balance box• Final inspect
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
Burton, Sharpe, Jenkins, Bossanyi: “Wind Energy Handbook”
Mark Higgins 9/15/2011 Presentation at ISU
Mark Higgins 9/15/2011 Presentation at ISU
Mark Higgins 9/15/2011 Presentation at ISU
Mark Higgins 9/15/2011 Presentation at ISU
Mark Higgins 9/15/2011 Presentation at ISU
Mark Higgins 9/15/2011 Presentation at ISU
Assembly Variation
43
• Maintain +-mm across 50m assembly
• Joints are critical
http://mag-ias.com/index.php?id=308&L=2
Rapid Material Placement Systems (RMPS)Automated blade molding
Automated root end machining for wind bladesMachine adapts automatically to blade position Machining processes: Sawing, milling, boring and trimming
Future Automation Systems?
Options for Large(r) Blades
• Manufacturing– Make at point of use– Make in region of use– Import
• Design– Flatback design– Design in 2 pieces– Materials to reduce
weight
Remote Blade Manufacturing Demonstration – Sandia 2003