Researchers at the University of California, San Diego (UCSD) Jacobs School
of Engineering have received a $2.5 million Multidisciplinary University
Research Initiative (MURI) grant to develop and test a metallic composite
material capable of changing shape and then returning to its original
form. The research is funded by the Office of Naval Research and may have
applications for ships, submarines, and other vehicles and structures.


"The use of shape memory alloys is very attractive because it enables large
global recoverable, super-elastic deformations of up to six percent, a
ten-fold over conventional elastic response. We hope to elicit even
greater super-elastic performance by creating a hybrid composite alloy
material" says Sia Nemat-Nasser, director of the Center of Excellence for
Advanced Materials and principal investigator for the project.


Although shape-memory alloys have been around for over 30 years,
Nemat-Nasser and his colleagues are adding a new spin by combining them
with other non-metallic materials. He is working with Kenneth Vecchio, a
professor of materials science at the School, and representatives from
Caltech and the University of Washington, to use plates of shape-memory
nickel-titanium (Ni-Ti) to sandwich shape-memory, super-elastic foams and
rods embedded with hollow glass beads.


"This unique combination should allow for even greater flexibility and
resilience in a very lightweight structure," explains Nemat-Nasser. "The
hybrid material should provide optimal energy absorbing capability against
high-velocity projectile impact, explosion-induced shock, or other dynamic
events." In other words, the absorbing capability, in conjunction with the
material's flexibility, could enable it to stop cracks and collateral
damage by distributing the forces from impact.


To test the new alloy composite, Nemat-Nasser and his coworkers will use a
variety of devices, including a full complement of novel Hopkinson bars,
gas guns, high-speed cameras, and high-speed X-ray machines, as well other
common materials processing and characterization equipment.


Nemat-Nasser is a member of the National Academy of Engineering (NAE), and
most recently received the 2002 William Prager and Nadai Medals.

Media Contact:

Troy Anderson, (858) 822-3075 or tdanderson@ucsd.edu

Video is available here .

Related Links:

Jacobs School of Engineering

Center of Excellence for Advanced Materials (CEAM)

Office of Naval Research

Multidisciplinary University Research Initiative