Blade Reliability & Composite Materials

Improving wind-turbine blade manufacturing quality and determining the most cost-effective methods to mitigate environmental damage.

Unplanned maintenance and component failures are a concern to both wind plant owners and wind turbine manufacturers. Sandia leads efforts in wind-turbine reliability research, specifically focusing on:

  • Wind plant reliability & analysis
  • Nondestructive inspection
  • Composite materials research
  • Optimized carbon fiber composites
  • Structural health monitoring
  • Effects of blade defects
  • Leading edge erosion

Through this work, Sandia is ensuring that wind energy technology will deliver economical, reliable, clean energy to the nation.

Wind Plant Reliability & Analysis

Sandia works with industry partners to collect and analyze wind turbine reliability data in order to improve the predictability and reliability of wind power generation and operations. Researchers are analyzing proprietary data from industry partners to provide generalized characterizations of wind plant reliability issues and opportunities for improvement. When complete, these databases will allow industry to self-assess their turbines’ performance and make more informed operations decisions that improve power generation.

Nondestructive Inspection

Sandia National Laboratories’ Infrastructure Assurance and Non-Destructive Inspection Department began as part of the Federal Aviation Administration’s (FAA) program to improve the airworthiness of the U.S. commercial aviation fleet, and transition from “safe-life” to “damage tolerant design.” This transition required the development of improved design, inspection, and repair processes, that have since been applied to military aircraft, spacecraft, bridges, automobiles, trains, oil and gas industry equipment, and now wind blades.

The Wind Blade Non-Destructive Inspection Center now includes wind blade inspection specimens and inspection technology specifically suited to wind blades. Real and engineered specimens include all flaws and damage types that are commonly found in wind blades in both manufacturing floor and field settings.

Drawing from experience inspecting composite aviation parts, Sandia has created a set of wind-blade-specific inspection specimens that mimic commonly seen blade flaws—allowing manufacturers to test and refine their equipment to better diagnose blade flaws.

The Wind Blade Non-Destructive Inspection Center provides the following capabilities and expertise:

  • Nondestructive Inspection (NDI)
  • Automated & Robotic Inspection Deployment
  • Structural Health Monitoring (SHM) and Sensor Development
  • Composite Fabrication and Structural Repair
  • Structural Mechanics & Damage Tolerance Analysis
  • Fatigue, Fracture & Strength Mechanical Testing
  • Reliability and Probabilistic Analysis

Composite Metals Research

Longer blades present new technical and economic challenges that cannot be addresses without a thorough understanding of composite material behavior in realistic wind applications.  Since 1989, Sandia and its partners at Montana State University have tested and reported key data and trends on fiber-reinforced polymers (composites) and other materials used in the construction of wind turbine blade. Developers and researchers can access the results of more than 1600 tests on more than 500 materials in the DOE/SNL/MSU Wind & Marine Energy Composites Database.

Sandia’s composites research capabilities include:

  • Testing the effects of common flaws in composites on properties in fatigue loading
  • Characterizing new materials such as urethane resins, aligned strand material forms, and carbon fiber composites
  • Studying crack growth and delamination in adhesive and core materials
  • Establishing full 3-D properties of thick laminates
  • Developing substructure testing capabilities in order to capture the realistic and complex loading experienced by modern wind-turbine blades.
  • Incorporating new test diagnostics such as Acoustic Emission Spectroscopy to improve understanding of in-situ material behavior

Download the latest database (v. 29.0)

Optimized Carbon Fiber Composites

Carbon fiber reinforced polymers (carbon fiber composites) offer significantly enhanced mechanical properties compared to the more widely used glass fiber reinforced polymers, enabling the design and manufacture of larger, high energy capture wind turbine rotors. However, commercial carbon fiber materials are much costlier than glass fiber, hindering their broader adoption in the wind industry. Carbon fiber composites were originally designed and applied to military and aerospace applications where strength is paramount and cost was not a primary factor. Thus, significant opportunities exist to reduce the overall cost of incorporating carbon fiber materials into a wind turbine blade where cost is a primary factor. These opportunities range from changing the raw material inputs, fiber conversion processes, and formats of the carbon fiber itself, through the composite material forms (e.g. pultrusion, prepreg) used in the blade manufacturing process.

The magnitude of the wind-specific value improvement of novel carbon fiber materials is determined through characterization of carbon fiber material properties by performing mechanical testing and accurate cost modeling. The performance of study carbon fiber materials is assessed through blade system optimization studies for representative wind turbine reference models.

Sandia and its partners have performed research on novel carbon fiber materials to assess the commercial viability to develop cost-competitive carbon fiber composites specifically suited for the unique loading experienced by wind turbine blades. This work enables the continued reduction in the levelized cost of energy (LCOE) for wind turbines installed in the United States, including low wind resource and offshore sites, and has established routes for the broader adoption of carbon fiber materials in wind turbine blade design beyond existing commercial materials.

Coupon testing is used to characterize new composite materials to obtain design properties.

Structural Health Monitoring

Sandia develops reliable strategies to detect damage in the rotor blades early enough to allow operators to make operations, maintenance and repair decisions that will reduce costs. Researchers developed a Structural Health and Performance Management System, a cost-effective, simulation-based approach for preventing, detecting and addressing damage. This method bridges the gap between detecting damage in a wind turbine blade and making revenue-optimizing O&M decisions based on the effects of the damage.

Sandia’s Damage Simulation Method

Effects of Blade Defects

Defects in wind turbine blades can have wide range of effects depending on their location, material, type, and size. Because existing inspection procedures from other industries often miss defects, manufacturers overdesign blades to account for possible defects.

Sandia researchers use nondestructive inspection techniques on flawed blade specimens to characterize flaws and determine the ultimate effects of undetected defects.

Leading Edge Erosion

Leading edge erosion is an emerging issue in wind turbine blade reliability, causing performance decreases and additional maintenance costs.  Through the U.S. DOE Blade Reliability Collaborative, researchers from Sandia National Laboratories (SNL), Texas A&M, and U.C. Davis have recently addressed the subject of performance loss. This project includes roughness measurements at wind plants experiencing blade soiling and erosion, wind tunnel testing of airfoils with representative roughness and erosion levels, and the development of a model that captures the performance effects of blade surface roughness and erosion.

More information on this work, including several reports and a data archive, are available on the Leading Edge Erosion website.

Josh Paquette, Blade Reliability & Composite Materials, Structural Health Monitoring

(505) 844-7766

Ben Karlson, Wind Plant Reliability & Analysis

(505) 377-3774

Brandon Ennis,Composite Metals Research, Optimized Carbon Fiber Composites

(505) 845-8646

Davis Maniaci, Effects of Blade Defects

(505) 844-4664