Teecht. Regular Army Excogitation Could Meliorate Business Office Of Helmets, Facial Protection & More

Army together with MIT researchers advanced a unique experimental device to improve exam the durability of high functioning together with robust polymeric materials that look to strengthen themselves nether assail yesteryear rapid impact.

The Army Research Laboratory’s medico Alex Hsieh, along amongst Prof. Keith A. Nelson, medico David Veysset together with medico Steven Kooi, from the Army’s Institute for Soldier Nanotechnology at MIT, discovered that when targets made of poly(urethane urea) elastomers, or PUUs, are impacted at rattling high speed yesteryear micro-particles made of silica, the PUU target shows hyperelastic behavior. That is, they operate extremely rigid when deformed at strain rates on the gild of 108/s, which way some that the stuff of the target deforms to one-half of its master copy thickness inward an extremely brusque fourth dimension equal to ane 2nd divided yesteryear hundred millions. PUUs too bounce dorsum later on the impact, Hsieh said.

The exam device uses a pulsed Light Amplification by Stimulated Emission of Radiation to shoot micrometer-sized bullets at targets made of PUUs. Researchers found, for the outset time, “behaviors that contrast greatly to the direct upon answer observed inward a cross-linked polydimethylsiloxane elastomer where micro-particles penetrated the target together with the target stuff did non bounce dorsum or completely recover.”

Scientists tell their regain on mass elastomers tin assist pattern matrix materials for composites for the time to come generation of U.S. Army fighting helmets. The Army’s enhanced fighting helmet uses high functioning ultrahigh molecular weight polyethylene, or UHMWPE, fibers based composites. These fibers convey high breaking strength, per unit of measurement cross department area, nearly 15 times stronger than steel but are flexible similar fabrics.

Traditional armor stuff designs include ceramics, metals together with lightweight fiber reinforced composites for both soldier together with vehicle protection, which are typically based on stiffness, the resistance of a stuff against deformation, toughness, the might to absorb unloose energy together with plastically deform prior to fracture.

Hsieh said the squad focused on polymers, which are made upwardly of a rattling large release of modest molecular units that are strung together to shape rattling long chains, which tin live good organized or randomly packed. Specifically, polymeric materials that are strong similar impact-resistant security spectacles or flexible similar rubbers. Elastomers are a shape of manmade rubbers, which tin live synthesized from a wide arrive at of polymer chemistries.

“They mostly convey depression Young’s modulus which way depression resistance to elastic deformation nether loading at ambient conditions, together with higher failure strain — the capability to sustain significantly greater amount of strain earlier failure — than most of the plastic materials,” he explained.

To farther validate the molecular influence, the squad has conducted comprehensive studies on PUUs along amongst a glassy polycarbonate. While polycarbonate is known for its high fracture toughness together with ballistic strength, these PUUs, regardless of their respective composition, exhibited greater dynamic stiffening during direct upon at strain rates on the gild of 108/s. Furthermore, the resistance against penetration of the micro-particle tin live optimized, i.e. a l per centum reduction inward the average maximum depth of penetration was achieved yesteryear only varying the molecular composition of PUUs.

“This is rattling exciting,” Hsieh said. “Seeing is believing. New agreement from these enquiry discoveries — the essence of hyperelastic phenomenon inward mass elastomers, peculiarly at the minute of target/impulse interaction, strongly points out to live a plausible pathway telephone substitution to manipulating failure physics together with towards a novel pattern epitome for robust materials.”

In improver to fighting helmets, other potential applications of robust high functioning elastomers for soldier protection include but are non express to transparent confront shields, mandible confront shields, ballistic vests, extremity protective gear, together with blast-resistant fighting boots.