Structural properties of laminated Douglas fir/epoxy composite material

Spera, D. A.; Esgar, J. B.; Gougeon, M.; Zuteck, Michael

doi:10.2172/6492500

Cited by 16 publications

(15 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The efficiency of the joint depends on the chosen geometry. Finger joints were used in the wood-epoxy blades of the MOD-5A turbine (General Electic Company/NASA/DOE, USA) [92]. However, the use of this type of joint in modern fiberglass blades may be impeded by the higher modulus of elasticity and strains, as well as issues with tooling.…”

Section: Implementationsmentioning

confidence: 99%

The Concept of Segmented Wind Turbine Blades: A Review

et al. 2017

View full text Add to dashboard Cite

Abstract:There is a trend to increase the length of wind turbine blades in an effort to reduce the cost of energy (COE). This causes manufacturing and transportation issues, which have given rise to the concept of segmented wind turbine blades. In this concept, multiple segments can be transported separately. While this idea is not new, it has recently gained renewed interest. In this review paper, the concept of wind turbine blade segmentation and related literature is discussed. The motivation for dividing blades into segments is explained, and the cost of energy is considered to obtain requirements for such blades. An overview of possible implementations is provided, considering the split location and orientation, as well as the type of joint to be used. Many implementations draw from experience with similar joints such as the joint at the blade root, hub and root extenders and joints used in rotor tips and glider wings. Adhesive bonds are expected to provide structural and economic efficiency, but in-field assembly poses a big issue. Prototype segmented blades using T-bolt joints, studs and spar bridge concepts have proven successful, as well as aerodynamically-shaped root and hub extenders.

show abstract

Section: Implementationsmentioning

confidence: 99%

The Concept of Segmented Wind Turbine Blades: A Review

et al. 2017

View full text Add to dashboard Cite

show abstract

“…We currently believe bonded root studs are the most cost efficient method. Our team has completed engineering analyses and laboratory tests [3] that confirmed the strength of bonded studs originally developed for use in wood-epoxy wind turbine blades [4]. These studs are highly tapered to minimize the effects of stress concentrations in the joint.…”

Section: Blade Fabrication Processmentioning

confidence: 99%

Cost Study for Large Wind Turbine Blades

Ashwill¹

2003

View full text Add to dashboard Cite

The cost study for large wind turbine blades reviewed three blades of 30 meters, 50 meters, and 70 meters in length. Blade extreme wind design loads were estimated in accordance with IEC Class I recommendations. Structural analyses of three blade sizes were performed at representative spanwise stations assuming a stressed shell design approach and E-glass/vinylester laminate. A bill of materials was prepared for each of the three blade sizes using the laminate requirements prepared during the structural analysis effort. The labor requirements were prepared for twelve major manufacturing tasks. TPI Composites developed a conceptual design of the manufacturing facility for each of the three blade sizes, which was used for determining the cost of labor and overhead (capital equipment and facilities). Each of the three potential manufacturing facilities was sized to provide a constant annual rated power production (MW per year) of the blades it produced. The cost of the production tooling and overland transportation was also estimated. The results indicate that as blades get larger, materials become a greater proportion of total cost, while the percentage of labor cost is decreased. Transportation costs decreased as a percentage of total cost. The study also suggests that blade cost reduction efforts should focus on reducing material cost and lowering manufacturing labor, because cost reductions in those areas will have the strongest impact on overall blade cost.

show abstract

“…20 The MOD-5A test work used fingers nearly 300 mm long, and test lab specimens were used to gather data on 150 mm finger lengths. However, calculations indicated mat performance was likely to improve until a finger size around 25 mm, at which point the defect introduced by the finger tips would begin to merge with the level of natural defects in the laminated material.…”

Section: Jointed Designsmentioning

confidence: 99%

Alternative materials, manufacturing processes, and structural designs for large wind turbine blades

Griffin

2002

2002 ASME Wind Energy Symposium

View full text Add to dashboard Cite

As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies program, Global Energy Concepts LLC (GEC) has performed a study concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. Constraints to cost-effective scaling-up of the current commercial blade designs and manufacturing methods are identified, including self-gravity loads, transportation, and environmental considerations.A trade-off study is performed to evaluate the incremental changes in blade cost, weight, and stiffness for a wide range of composite materials, fabric types, and manufacturing processes. Fiberglass / carbon hybrid blades are identified as having a promising combination of cost, weight, stifmess and fatigue resistance. Vacuum-assisted resin transfer molding, resin film infusion, and pre-impregnated materials are identified as having benefits in reduced volatile emissions, higher fiber content, and improved laminate quality relative to the baseline wet lay-up process. Alternative structural designs are identified, including jointed configurations to facilitate transportation. Based on the study results, recommendations are developed for further evaluation and testing to verify the predicted material and structural performance. BACKGROUND

show abstract

Structural properties of laminated Douglas fir/epoxy composite material

Cited by 16 publications

References 3 publications

The Concept of Segmented Wind Turbine Blades: A Review

The Concept of Segmented Wind Turbine Blades: A Review

Cost Study for Large Wind Turbine Blades

Alternative materials, manufacturing processes, and structural designs for large wind turbine blades

Contact Info

Product

Resources

About