Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Compression experiments lead to shocking results

26.09.2011
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."

... more about:
»LLNL »Livermore »Security Forum

"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.

More Information

Jonathan Crowhurst

"New form of girl's best friend is lighter than ever," LLNL news release, May 17, 2011.

"Shocking results from diamond anvil cell experiments," LLNL news release, July 6, 2010.

Founded in 1952, Lawrence Livermore National Laboratory provides solutions to our nation's most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administratio

Anne Stark | EurekAlert!
Further information:
http://www.llnl.gov

Further reports about: LLNL Livermore Security Forum

More articles from Physics and Astronomy:

nachricht Breaking the optical bandwidth record of stable pulsed lasers
24.01.2017 | Institut national de la recherche scientifique - INRS

nachricht European XFEL prepares for user operation: Researchers can hand in first proposals for experiments
24.01.2017 | European XFEL GmbH

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>