The Naval Surface Warfare Center - Carderock Division recently published a paper titled "Flexural Testing of Steel Wire Composite Beams Made with Hardwire® Unidirectional Tape". The United States Navy, initially interested in the potential to transition composite parts to steel structures, has uncovered other uses during their testing. Tests indicated flexural composite strengths of nearly 260 ksi as well as composites exhibiting ductile properties and non-catastrophic failure modes. During the testing process, Hardwire LLC developed a new product offering which dramatically increased the compressive qualities of the Hardwire® product and actually moved the failure mode from the compressive side of the laminate to the tensile side.

Some quotes of note from the paper: "Of particular interest was the apparent ductile region exhibited by the laminates...ductile failure is not characteristic of traditional composite materials and may present the potential for improved ballistic and or blast protective properties." "... it is likely that the increased flexural strength observed in the 3S wire is due to ductile behavior of the 3S specimen, indicative of a greater degree of load sharing within the beam."

And finally: "...it should also be noted that none of the Hardwire® test specimen resulted in complete or catastrophic failure typical of traditional high stiffness unidirectional composite materials. In each test, the initial failure was limited to the surface wires (either compressive buckling or tensile fracture), leaving the bulk of the material relatively intact. This is an attractive property for primary or critical structures where post-damage structural integrity is needed."

Hardwire LLC can be reached at (410) 957-3669 / www.hardwirellc.com

Roger Crane - NSWC-Carderock Division can be reached at cranerm@nswccd.navy.mil.

Hardwire® products may be purchased directly via this website or though distribution at Composites One.