Transmaterial

Glare

After a bomb went off in 1988 on Pan Am flight 103 over Lockerbie, Scotland, killing all 259 passengers onboard, the Federal Aviation Administration created standards that industry would have to meet if it chooses to deploy luggage containers capable of withstanding such a blast. During the 1990s, the FAA tested 10 hardened luggage containers made from a variety of materials, including reinforced aluminum, fiberglass, aramid fibers and polymers.

Only one container - concocted from fiber-metal laminates developed originally by the Delft University of Technology in the Netherlands - passed the FAA's test and received certification. The material, called Glare (short for glass reinforced), consists of multiple aluminum layers interspersed with layers of fiberglass and adhesive bonding that are supple yet strong. When used in fabricating luggage containers, Glare can absorb bomb blasts without breaching.

As Glare expands with a blast, it absorbs the explosive energy and redistributes the impact load to the adjacent surface area rather than to one specific weak spot. The bomb blast leaves a sizable deformation in the container's surface, but it remains intact. Moreover, whereas other FAA-tested containers were also able to contain the bomb blast, Glare, whose glass fibers boast a melting point of 1,500 degrees Celsius, could resist the subsequent luggage-fueled fire inside the container. The post-blast fire melts Glare's innermost aluminum layer, but in doing so the underlying adhesive bond carbonizes, keeping the fiberglass layers in place and effectively forming a fire wall that prevents the container from collapsing.

Glare is considered suitable for any application where a strong and relatively lightweight material is desirable. It may be fashioned into windmill blades, the hull of a high-speed boat, or a police shield. [Excerpted from David McMullin, "Lockerbie Insurance" in Scientific American, January 2002, pp.15-16]

posted by Blaine @ 12:31 PM