Bilisik K.,3TEX, Inc.
Journal of the Textile Institute | Year: 2010
Multiaxis 3D-woven carbon preforms are fabricated using prototyped multiaxis weaving. The fabricated preform has structural instability at thickness. For this reason, the structural parameter and processing parameters were evaluated to make uniform preform and to understand the preform-process relations. The important process parameters are identified and described to enhance the preform and unit cell architecture. Also, preform structural parameters are analyzed in terms of fiber cross-section and fiber tow size, bias angle, and fiber waviness. The useful recommendation is also to make uniform multiaxis 3D-woven preform for composites. © 2010 The Textile Institute. Source
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 436.17K | Year: 2009
Supersonic cruise missiles offer the ability to hit a time critical target with precision and lethality from long distances, yet the high speed generates temperatures on the exterior surfaces of the missile that can exceed the limitations of high temperature structural metals like titanium. Also, insulation to protect electronics equipment in the missile is required. One solution that demonstrates promise for high-temperature, structural antenna windows is structural ,low dielectric constant, oxide-oxide ceramic matrix composite (CMC) based on a 3-D woven preform that integrates the thermal protection system. The 3-D preform consists of ceramic fabric skins separated by through-thickness reinforcements, or Z-yarns, woven into each skin. Structures based on oxide-oxide systems have suitable dielectric properties and can withstand the anticipated high temperatures. The 3-D oxide fiber architecture also provides a means for optimizing the overall system performance since many key properties depend primarily on the details of the Z-yarn placement and volume fraction. The Phase I effort successfully demonstrated fabrication of two Nextel 720 preforms infused with alumina matrices. The proposed Phase II program will further develop the design space associated with the integral standoff CMC materials, characterize a matrix of the standoff materials, and resolve remaining manufacturing challenges.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.83K | Year: 2009
Wind blades are a significant part of the installation and operating costs of wind turbines used for electricity generation. In the manufacture of wind blades, several composite elements must be joined; the joints between these elements present one of the most difficult aspects of their construction. Current practices are hand-labor intensive and result in thick bond lines. In turn, these practices lead to manufacturing defects and too often to premature failure of the wind blades. Pi joints, which are shaped like the Greek letter p and based on three-dimensional (3-D) fiber architectures, have been shown to increase joint strength in carbon composite aircraft structures and in glass composite naval structures by more than two fold. This project will develop technology for replacing current structures with Pi and ¿Y¿ joints based on 3-D fiber architectures. Commercial Applications and other Benefits as described by the awardee:The technology not only would lead to stronger wind turbine joints but also to a more robust, less costly manufacturing process. Installation costs of the turbines would be reduced by the lower cost wind blades, and operating costs would be reduced by the lower number of wind blade failures
Agency: Department of Homeland Security | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 332.52K | Year: 2010
Based on the results of the Phase I project, it was shown that 3TEX`s unitary 3D woven E-Glass billet reinforced composite panels have excellent potential to be used as blast mitigating material for protecting buildings. Fibers and resins used in the Phase I were selected with affordability and fire resistance as the major considerations. In the Phase II effort proposed, the same fiber and resin will be used. The 3D woven billet preform design will be optimized and, based on the new geometry, predictive analysis will be conducted to determine that performance under shock loading is still at the same level found in Phase I or better. The new material will be produced and tested in the University of Rhode Island (URI) shock tube for validation. Large scale blast testing of mock-up concrete walls will be conducted using three different mounting approaches. An innovative attenuator will be used to reduce the shock load transmitted through the mounting bolts to the wall. A patented coupler will also used to simulate the joining of two panels in a vertical installation. At the end of the Phase II, a complete technical data package (TDP) for the materials and methods used, will be developed.
Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase I | Award Amount: 100.00K | Year: 2010
A novel method of fabricating carbon nanotube (CNT) reinforced polymer matrix composites is proposed. It includes growing super-aligned carbon nanotube arrays on a flat substrate, using NCSU proprietary shear pressing method to compress the grown arrays into a layer of densely packed, highly aligned CNTs inclined at an angle of several degrees to the substrate, separating the produced CNT sheet from the substrate, infusing polymeric resin into the sheet to fabricate an uncured prepreg, laying up the prepreg plies at desired orientations, and finally curing the laminate. This manufacturing process will result in a thick, high CNT volume fraction reinforced laminate with unique in-plane and out-of-plane reinforcement architectures. This kind of laminates can be used for relatively small size aerospace structures, where special combinations of high mechanical strength, high electrical conductivity and high thermal conductivity are required. Experimental validation and scaling up this technological approach will include increasing CNT length and their array growth area, building computer controlled apparatus for precise shear pressing of the grown arrays, developing special means for aerospace grade resin infusion into CNT sheets, ply lamination and cure. Initial experimental studies will include in-plane tensile testing and measurements of through thickness electrical and thermal conductivities. BENEFIT: Aerospace industry may be primarily interested in using these novel CNT reinforced prepregs and composite laminates for unique structures which require low weight and high strength combined with high electrical and/or high thermal conductivity. Immediate applications may include light-weight composite structures for housing various aircraft electronic systems. Currently available composite laminates are not applicable due to their low through-thickness thermal and electrical conductivities. In the proposed CNT prepregs and laminates, with long CNTs extending through the whole ply thickness, these properties will be elevated to a much higher level, at least an order of magnitude. The development of integrated manufacturing cycle for these materials and their structural components will enable to supplying them in large volumes for the next generation unmanned aircraft and surveillance platform structures, as well as for the future civil transport systems.