Featured Research

from universities, journals, and other organizations

Heat Used To Identify Weaknesses In Wind Turbine Rotor Blades

Date:
March 23, 2009
Source:
Fraunhofer-Gesellschaft
Summary:
Is the wind turbine’s rotor blade still intact? Or does it have tiny air bubbles that could expand and eventually cause a fracture? Material defects can be quickly and cost-efficiently detected using infrared thermography.

Telltale heat.
Credit: Image courtesy of Fraunhofer-Gesellschaft

At first glance, the rotor blade appears to be flawless, but the expert knows that outward appearances cannot be trusted. He taps the surface and listens. A full, deep sound tells him that the laminate is homogeneous, while a more flat, hollow tone indicates irregularities in the material.

Delaminated and hollow sections of a certain size near the surface can also be detected by running an expert hand over the surface material. But even an experienced inspector cannot find all hidden faults in this way.

Rotor blades consist mainly of glass fibers which are processed to form mats or meshes. In order to make a 60-meter rotor blade, hundreds of these mats have to be laid flat inside a mold and impregnated with special resins in a vacuum. Even minor irregularities can cause air bubbles or other faults to form, and these often lead to mechanical stresses in the material when the blade is subjected to everyday loads. As a consequence, the laminate can rip and cause the rotor blades to fail prematurely.

Researchers at the Fraunhofer Wilhelm-Klauditz-Institut WKI in Braunschweig are able to make such faults visible. “Infrared thermography is well suited to this task, as it is fast, relatively cheap and doesn’t cause any damage,” explains WKI project manager Dr. Hiltrud Brocke. “The surface is briefly heated with an infrared radiator. A special camera shows how the heat front spreads inside the material. If the front hits on any air inclusions or delaminated areas, it accumulates because heat spreads less in air than in solid laminate.” In this way, the researchers can peer several centimeters into the material.

“Because the equipment – the infrared radiator, a camera and a computer – is mobile, we can carry out measurements during production, at the end of the transport route, and also on fully assembled wind energy plants,” says Brocke. The researchers will be demonstrating their technology on a rotor blade section incorporating several typical faults at the Hannover-Messe from April 20 to 24.


Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.


Cite This Page:

Fraunhofer-Gesellschaft. "Heat Used To Identify Weaknesses In Wind Turbine Rotor Blades." ScienceDaily. ScienceDaily, 23 March 2009. <www.sciencedaily.com/releases/2009/03/090323093131.htm>.
Fraunhofer-Gesellschaft. (2009, March 23). Heat Used To Identify Weaknesses In Wind Turbine Rotor Blades. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2009/03/090323093131.htm
Fraunhofer-Gesellschaft. "Heat Used To Identify Weaknesses In Wind Turbine Rotor Blades." ScienceDaily. www.sciencedaily.com/releases/2009/03/090323093131.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins