skip to main content


The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 11:00 PM ET on Thursday, May 23 until 2:00 AM ET on Friday, May 24 due to maintenance. We apologize for the inconvenience.

Title: Material and Structural Characterization of a Wind Turbine Blade for Use as a Bridge Girder

Fiber reinforced polymer (FRP) composite materials have been used in a variety of civil and infrastructure applications since the early1980s, including in wind turbine blades. The world is now confronting the problem of how to dispose of decommissioned blades in an environmentally sustainable manner. One proposed solution is to repurpose the blades for use in new structures. One promising repurposing application is in pedestrian and cycle bridges. This paper reports on the characterization of a 13.4-m long FRP wind blade manufactured by LM Windpower (Kolding, Demark) in 1994. Two blades of this type were used as girders for a pedestrian bridge on a greenway (walking and biking trail) in Cork, Ireland. The as-received geometric, material, and structural properties of the 27 year-old blade were obtained for use in the structural design of the bridge. The material tests included physical (volume fraction and laminate architecture) and mechanical (tension and compression) tests at multiple locations. Full-scale flexural testing of a 4-m long section of the blade between 7 and 11 m from the root of the blade was performed to determine the load-deflection behavior, ultimate capacity, strain history, and failure modes when loaded to failure. Key details of the testing and the results are provided. The results of the testing revealed that the FRP material is still in excellent condition and that the blade has the strength and stiffness in flexure to serve as a girder for the bridge constructed.

more » « less
Award ID(s):
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
SAGE Publications
Date Published:
Journal Name:
Transportation Research Record: Journal of the Transportation Research Board
Page Range / eLocation ID:
p. 354-362
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. The purpose of this study was to develop a replicable methodology for testing the capabilities and characteristics of a wind turbine blade in a structural re-use application with the specific goal of creating and demonstrating an efficient and commercially viable wind blade pedestrian bridge design. Wind energy experienced a dramatic increase in popularity following the turn of the century and it is now a common source of renewable energy around the world. However, while wind turbines are able to produce clean energy while in service, turbine blades are designed for a fatigue life of only about 20 years. With the difficulty and costs associated with recycling the composite material blades used on the turbines, wind power companies choose to dispose of decommissioned blades in landfills instead. The Re-Wind BladeBridge project aims to promote a more sustainable life cycle for wind power by demonstrating that decommissioned wind turbine blades have the capability to be repurposed as structural elements in bridges. This paper presents an analysis and characterization of a LM 13.4 wind blade from a Nordex N29 turbine, along with a design for a pedestrian bridge using two LM 13.4 wind blades to create a 5-meter span bridge. Software developed by the Re-Wind team called “BladeMachine” was used to generate the engineering properties of the blade at multiple sections along the blade length. Resin burnout tests and mechanical testing in tension and compression were performed to determine the material and mechanical properties of the composite materials in the blade. Additionally, a four-point edgewise bending test was performed on a 4-meter section of the wind blade to evaluate its load carrying behavior. The results of these tests revealed that the LM 13.4 blades are suitable to be re-utilized as girders for a short-span pedestrian bridge. An overview of the design of the BladeBridge currently under construction in County Cork, Ireland is presented, including details on the architectural and structural design processes. 
    more » « less
  2. The rapid increase in the wind energy sector has brought forward a challenging problem of disposing off a huge quantity of non-biodegradable, thermosetting fibre reinforced polymer (FRP) composite materials used in wind turbine blades. Most of the existing solutions are either not sustainable or not economical. This study focuses on re-use options. In this paper a design option for re-using decommissioned wind turbine blades in pedestrian bridges is presented. To demonstrate the concept, an 8.5 m long pedestrian bridge is designed using parts taken from two A29 (modified version of Vestas V27) windblades. A preliminary code-based structural analysis is carried out to assess practicality of the proposed design and to check strength and serviceability requirements given in the prescribed codes. The results show that proposed design full-fills the strength criteria and serviceability requirements recommended in the Eurocodes. The maximum strength utilisation of the blade components is found about 61% and deflection is limited to span/303. 
    more » « less
  3. Millions of tons of GFRP composites are expected to stockpile in the next 20-30 years from decommissioning wind turbine blades, which are made primarily of these materials. Responsible and attractive solutions are currently being studied by several research teams across Europe and the United States. The Re-Wind Network is one of these research teams that focuses on developing strategies and methodologies to transform the decommissioned wind blades into ready-to-use civil infrastructure (e.g., pedestrian bridge girders and power transmission poles). This paper reports on testing of a part of a full-sized power transmission pole prototype, made from a decommissioned GE37 wind turbine blade, and loaded in the gravity direction mimicking expected loads during its “new” lifetime. Full-scale connection testing is summarized and combined with the results of the test on the 5.5 m high full-size section of the prototype to obtain safety factors for various structural components under different expected load cases (these include gravity, wind, and ice loads). Structural Integrity of the various components of the power pole is studied to prove efficacy of the proposed second-life application of the decommissioned wind blade as a power transmission pole. Recommendations to improve the design for the planned future field full-blade prototyping are emphasized.

    more » « less
  4. This paper describes repurposing projects using decommissioned wind turbine blades in bridges conducted under a multinational research project entitled “Re-Wind”. Repurposing is defined by the Re-Wind Network as the re-engineering, redesigning, and remanufacturing of a wind blade that has reached the end of its life on a turbine and taken out of service and then reused as a load-bearing structural element in a new structure (e.g., bridge, transmission pole, sound barrier, seawall, shelter). The issue of end-of-life of wind turbine blades is becoming a significant sustainability concern for wind turbine manufacturers, many of whom have committed to the 2030 or 2040 sustainability goals that include zero-waste for their products. Repurposing is the most sustainable end-of-life solution for wind turbine blades from an environmental, economic, and social perspective. The Network has designed and constructed two full-size pedestrian/cycle bridges—one on a greenway in Cork, Ireland and the other in a quarry in Draperstown, Northern Ireland, UK. The paper describes the design, testing, and construction of the two bridges and provides cost data for the bridges. Two additional bridges that are currently being designed for construction in Atlanta, GA, USA are also described. The paper also presents a step-by-step procedure for designing and building civil structures using decommissioned wind turbine blades. The steps are: project planning and funding, blade sourcing, blade geometric characterization, material testing, structural testing, designing, cost estimating, and construction.

    more » « less
  5. Zingoni, A. (Ed.)
    This paper presents two case studies of the repurposing projects of decommissioned wind turbine blades in architectural and structural engineering applications conducted under a multinational research project is entitled “Re-Wind” ( that was funded by the US-Ireland Tripartite program. The group has worked closely together in the Re-Wind Network over the past five years to conduct research on the topic of repurposing of decommissioned FRP wind turbine blades. Repurposing is defined by the ReWind team as the reverse engineering, redesigning and remanufacturing of a wind blade that has reached the end of its life on a turbine and taken out of service and then reused as a load-bearing structural element in a new structure (e.g., bridge, transmission pole, sound barrier, sea-wall, shelter). Further repurposing examples are provided in a publicly available Re-Wind Design Catalog. The Re-Wind Network was the first group to develop practical methods and design procedures to make these new “second-life” structures. The Network has developed design and construction details for two full-size prototype demonstration structures – a pedestrian bridge constructed in Cork, Ireland in January 2022 and a transmission pole to be constructed at the Smoky Hills Wind Farm in Lincoln and Ellsworth Counties, in Kansas, USA in the late 2022. The paper provides details on the planning, design, analysis, testing and construction of these two demonstration projects. 
    more » « less