N24A-T006 TITLE: Manufacturing Method Development of Nanocomposite Steel Wire for Arresting Gear Purchase Cable

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Sustainment

OBJECTIVE: Develop a manufacturing method capable of producing nanocomposite steel wires (steel infused with carbon nanotubes) with requisite volumes to produce metal matrix composite (MMC) arresting gear purchase cable at a cost that is comparable to steel-only cable.

DESCRIPTION: Aircraft are recovered on Navy carriers by means of a steel arresting gear cable that catches the aircraft tailhook. The cable is connected to arresting gear below decks that absorbs the aircraft’s kinetic energy and stops the aircraft. Service life of the cable under repeated mechanical loading and degradation-inducing environmental conditions is critical, since the cable is the largest driver of operational cost in the Aircraft Launch and Recovery Equipment (ALRE) program. Service use cycles, as well as corrosion and bend-over-sheave wear and fatigue, are critical performance factors for such cables. To improve these characteristics, the Navy has been investigating composite carbon nanotube (CNT)/steel material as an alternative cable material to steel. The issue is manufacturability – current methods of extruding steel wire require applying 1,400–1,500 °C heat, which would degrade CNTs. The Navy is interested in a novel extrusion process that can effectively produce wire at a maximum 400 °C to protect the CNT properties. Additionally, process costs must be comparable to current steel-only processing costs for the CNT/steel cable to be viable.

The arresting gear cable is comprised of two separate cables: the cross-deck pendant and the purchase cable that is connected via a terminal and pin. The cross-deck pendant is the portion of the cable that is stretched across the landing area and interfaces with the aircraft tailhook. It is approximately 100 feet (30.48 m) long, and is replaced after approximately 125 cycles. The purchase cable is the portion of the cable that is reeved through the fairlead system and the arresting engine below the flight deck. It is comprised of 31 wires in a lang-lay construction, 1-7/16 in. (3.65 cm) in diameter and 2,200 ft (609.6 m) long. It is subject to bending stresses from the many sheaves, which with it is in contact, and is replaced after approximately 1,500 cycles. This composite cable SBIR topic addresses only the purchase cable. Cable construction should match current cable dimensions to facilitate direct replacement. The base metal for a new MMC cable should remain extra improved plow steel or a compositional equivalent. The nominal breaking strength of the composite cable should, at minimum, match the current cable’s 215,000 lbs (97,522.35 kg), in addition to improving the bend-over-sheave fatigue life.

The Navy requires the development of a manufacturing method capable of cost-effectively producing composite wires for arresting gear cables. The manufacturing method must be able to produce enough wire to fabricate a test batch of full-scale arresting gear purchase cables by the end of Phase II.

PHASE I: Develop and demonstrate a manufacturing method capable of bulk production of enough MMC wire to manufacture arresting gear purchase cable. Perform wire-wrap testing for ductility, reverse bend testing for fatigue resistance, along with tensile strength and reduction-of-area testing to ensure that all material standards are maintained. Demonstrate production of 100 ft (30.48 m) wire lengths and show scalability to meet the 2,200 ft (670.56 m) requirements for full-scale arresting gear purchase cables. Perform a cost-and-lifecycle analysis to determine any potential savings from extending the life of the purchase cable. Prepare a Phase I Option that, if exercised, will produce a sub-scale arresting gear purchase cable for bend-over sheave lifecycle testing. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Demonstrate manufacturing of full-scale arresting gear purchase cables. Determine maximum production rate and final wire rope properties. Final demonstration shall be on a composite cable in a test environment representative of the arresting gear aboard ship, (either a test bench or arresting gear at NAVAIR Lakehurst, depending on the availability of non-SBIR funding. During a final demonstration, the composite cable will be cycled to failure, and the prototype must improve current service life and meet current performance requirements, particularly mechanical strength. Prepare a Phase III development plan to transition the technology to the Navy and potential commercial use.

PHASE III DUAL USE APPLICATIONS: Work with the PMA to field the technology, accounting for any requirements, restrictions, or performance parameters. The Arresting Gear IPT and pertinent engineering teams are planned to be synchronized during the entire process.

Commercial systems and infrastructure that requires high-performance load-bearing cables, as well as durable, highly conductive electronics cables can greatly benefit from the efforts in this topic, and can result in additional design flexibility. Elevator cables, bridge cables, electronic wiring, and other cable-supported stabilizing structures are among a few of several commercial applications that can benefit from the results of this topic.

REFERENCES:

1. Wire Rope Technical Board. (2005). Wire rope user’s manual, 4th ed. ARE. https://www.wireropetechnicalboard.org/products/wire-rope-users-manual-4th-edition-electronic
2. Sloan, F., Bull, S., & Longerich, R. (2005, September). Design modifications to increase fatigue life of fiber ropes. In Proceedings of OCEANS 2005 MTS/IEEE (pp. 829-835). IEEE. https://doi.org/10.11096/OCEANS.2005.1639856
3. Sloan, F., Nye, R., & Liggett, T. (2003, September). Improving bend-over-sheave fatigue in fiber ropes. In Oceans 2003. Celebrating the Past... Teaming Toward the Future (IEEE Cat. No. 03CH37492) (Vol. 2, pp. 1054-1057). IEEE. https://doi.org/10.1109/OCEANS.2003.178486

KEYWORDS: Manufacturing; nanocomposite; steel; cable; arresting; gear

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