Brian Pillay and Haibin Ning, Ph.D., shuffle their feet quickly, both bending their bodies at a 45-degree angle. There is an occasional grunt before the final sigh of relief after Pillay and Ning, a research associate and post-doctoral researcher in Materials Science and Engineering, finally lay the block of steel on the table.

Haibin Ning, left, Brian Pillay, center, and Uday Vaidya are developing new, low-cost composite materials that lighten the loads of Army soldiers and make stronger, lighter combat weaponry.

Meanwhile, Uday Vaidya, Ph.D., professor in Materials Science and Engineering, is maneuvering his much lighter block of glass-fiber-reinforced composite to its place next to the steel with relative ease. Bullet holes riddle both blocks, but one distinct difference is evident. Two bullets have penetrated the steel, leaving holes the size of a dime or greater; however, there are no holes on the backside of the composite – just two slightly protruding marks where the bullet finally stopped, unable to penetrate the 1 ½-inch thick block.

“This is what the composite material does – localizes the damage,” Vaidya explains. “The composite material has been shot by five different types of bullets, and the damage doesn’t extend from one end to the other.”

Why composite material?
The U. S. Army has become interested in composite materials and ways in which they can replace materials now used in everything from airplanes, tanks and projectiles to soldier helmets, shoe inserts and body armor. Vaidya is nearing the end of a four-year, $2 million contract from the Army Research Laboratory to develop new, low-cost composite materials that lighten the soldiers’ loads and make stronger, lighter combat weaponry.

A composite material can be made up of resins such as epoxy, phenolic or vinyl esters and are reinforced with high-strength glass, Kevlar or carbon fibers. Materials can weigh 80 percent less than steel, yet be more durable. That’s one reason many of the military’s vehicles – such as the Stryker, Abrams tanks, helicopters and ships — are being armored with composites.

Composite materials also are cheaper over the life of the product, Vaidya says. “If you look at manufacturing and material costs, one to one, steel will work out to be cheaper. But if you look at lifecycle costs in terms of repair-ability, durability, maintenance, replacement – with all of that factored in – composites always win out,” he explains.

Composites offer added benefits in protection, cost savings and transportation. It’s much easier to transport a vehicle or parts made of composites than steel due to the extreme differences in weight.

“The Army wants to lighten the load as much as possible and not lose any performance,” Vaidya says.
That is especially true in terms of weaponry. There are many small components that make up a projectile, and each part is heavy and costly. Vaidya and his team have been developing a composite material for the tail cone of tank projectiles. The tail cone is located on the back end of the projectile and is in place to provide aerodynamic stability and spin characteristics to the ammunition. Vaidya’s team has developed a composite tail cone that he estimates will save the Army 70 percent annually on its cost. The Army uses between 300,000 and 400,000 of these projectiles a year.

“So let’s say if it costs them $100 to make it, we could do it for $30 a piece,” he says. “That represents a tremendous amount of savings. And the good news is that all the initial testing they have done with it really looks promising.”

Men of Kevlar
Vaidya and his team also are working to make improved body armor using Kevlar and other composites. These include things such as improved helmets, shoe inserts and other items that protect extremities below the elbow and below the knee.

“Most of the existing solutions protect the front and back torso, but there’s not much protection being offered for the extremities, particularly below the elbow and below the knee,” he says. “If there is, it’s so heavy that they don’t want to wear it. We have to make it wearable, durable and at the same time pretty lightweight.”

The Army is developing a next-generation helmet with a composite insert that is capable of carrying cameras, night-vision wear and more without modifications. It should weigh less than three pounds, but offer the same level of protection. “It will be lighter, more efficient and multi-functional,” Vaidya says.
The hope is to extend that same technology to other body-armor components.

David Littlefield, Ph.D., and Jong-Eun Kim, Ph.D., in Mechanical Engineering are providing computer-modeling support on the body-armor project. By generating high-fidelity computer models, a number of material combinations and loading situations can be investigated virtually, thereby reducing a large number of experiments and manufacturing trials.

The body-armor phase of the project and the grant are scheduled for completion by May 2008. The UAB team has applied for the grant renewal and hopes to know soon if it will be extended.

“Each year the problem the Army wants our help with is different, which is exciting,” he says. “Hopefully we will be able to continue our work for them because it’s been a great learning experience for our staff and our students.”