Featured Research

from universities, journals, and other organizations

Compression experiments lead to shocking results

Date:
September 27, 2011
Source:
DOE/Lawrence Livermore National Laboratory
Summary:
Using acceleration one trillion times faster than a jet fighter in a maximum turn, researchers have gained new insight into dynamic compression of aluminum at ultra-high strain rates.

An electron micrograph image of a "crater" in an aluminum sample after it is is shocked and compressed.
Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory

Using acceleration 1 trillion times faster than a jet fighter in a maximum turn, researchers have gained new insight into dynamic compression of aluminum at ultrahigh strain rates.

Controlled shock compression has been used for decades to examine the behavior of materials under extreme conditions of pressure and temperature.

Using an ultrafast spectroscopic technique (used to track shocks on a time scale of ten trillionths of a second), Lawrence Livermore National Laboratory scientists Jonathan Crowhurst, Michael Armstrong, Kim Knight, Joseph Zaug and Elaine Behymer measured breakouts (driven by laser-induced shocks) in aluminum thin films with accelerations in the range of 10 trillion g's. The research appears in the Sept. 23 edition of the journal Physical Review Letters.

"The details of how solid materials rapidly deform on sub-micron-length scales have been the subject of speculation for decades," Armstrong said. "For the first time, our experiments can test fundamental scaling laws on time and length scales where they may start to break down at strain rates that are orders of magnitude larger than previously examined."

"In solids, a sufficiently large amplitude shock produces irreversible plastic deformation and relaxes the initial stress," Crowhurst said. "As the amplitude continues to increase, and if the shock drive is maintained, a steady-wave shock profile evolves, which propagates indefinitely without change in form."

But the team said that a fundamental understanding of shock-induced deformation is still lacking. In particular, little is understood about the behavior of materials, including metals, during the initial phase of shock compression and at high strain rates.

"Our original goal was not too ambitious," Crowhurst said. "We only wanted to show that measurements on ultrafast time scales could achieve consistency with longer time scale experiments. We did this, but then got a surprise - unexpected insight into shock wave phenomena."

The researchers measured shock rises in aluminum and obtained shock stresses, shock widths and strain rates. They used the information to test the validity, at ultrahigh strain rates, of the invariance of the dissipative action, as well as the dependence of the strain rate on the shock stress.

Though completely destroyed at the end of the experiment, the research team was able to see the aluminum being compressed to 400,000 atmospheres in about 20 trillionths of a second.


Story Source:

The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Lawrence Livermore National Laboratory. "Compression experiments lead to shocking results." ScienceDaily. ScienceDaily, 27 September 2011. <www.sciencedaily.com/releases/2011/09/110923130117.htm>.
DOE/Lawrence Livermore National Laboratory. (2011, September 27). Compression experiments lead to shocking results. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2011/09/110923130117.htm
DOE/Lawrence Livermore National Laboratory. "Compression experiments lead to shocking results." ScienceDaily. www.sciencedaily.com/releases/2011/09/110923130117.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
China Airlines Swanky New Plane

China Airlines Swanky New Plane

Buzz60 (Oct. 21, 2014) China Airlines debuted their new Boeing 777, and it's more like a swanky hotel bar than an airplane. Enjoy high-tea, a coffee bar, and a full service bar with cocktails and spirits, and lie-flat in your reclining seats. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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