N212-130 TITLE: Integrated Sensor Technologies for Composites

RT&L FOCUS AREA(S): General Warfighting Requirements (GWR)

TECHNOLOGY AREA(S): Materials / Processes;Sensors

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop integrated sensor technologies that can be incorporated into composite primary structures to allow for the monitoring and characterization of the structures� behavior to support their development, production, and sustainment.

DESCRIPTION: Composites materials are used extensively throughout the aerospace industry due to their great specific strength and stiffness. Unlike traditional metallic components, the ultimate performance of composites can be much harder to characterize and monitor because they are a product of the manufacturing process, can be susceptible to aging issues, and damage may be difficult to identify. Traditionally strain gages are used to characterize a structure and can only sense a very limited portion of that structure, are labor intensive to install, and can be susceptible to handling damage. Traditional strain gages and the associated wiring are generally only used for limited test activities and were not intended for prolonged monitoring and for durability over the deployment of the system. Embedded sensors would allow the structural integrity and behavior of composite structures to be effectively monitored to address the previously described challenges throughout the entire product lifecycle. This will help improve the depth of understanding of these products and assist in driving down lifecycle costs, particularly in the area of sustainment. This sensing system should be designed to operate within the environmental constraints that would be expected of aerospace composites and should be mindful of size and weight to minimize their impact to the flight vehicle while balancing the performance of the sensor.

The sensor system should consider the following parameters:

• Capable of taking distributed measurements over a length or area
• Max Span: ~10 ft
• Measurement distribution: ~inches
• Measuring one or more of the following, ranges shown are indicative of a representative order of magnitude:
• Strain (microstrain, inches, 0-5%)
• Displacement (0"-0.1")
• Impact detection/impact damage detection
• Delamination
• Force (0-10000�s lbs)
• Temperature (32F-500F)
• Modular interface with different data logging equipment
• Enable interfacing with lab console, remote data storage, or to a communication system for real time transmission
• Note that remote data storage would be removed before flight and would not need to survive flight loads
• Service life of greater than 25 years.
• Can be powered by either an internal or external power source.
• System size and weight should consider that some elements may be integrated with a flight system and will need to be minimized as much as practical.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by DoD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence Security Agency (DCSA). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this project as set forth by DCSA and SSP in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advanced phases of this contract.

PHASE I: Define and develop inspection and sensor concepts and assess their feasibility. Examine concept formulation, development, and possible validation that could include subscale demonstration, including data logging operations. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. Prepare a Phase II plan.

PHASE II: Develop and validate a prototype (not necessarily hardware). Solidify the process for designing and incorporating the sensors into a variety of structures, such as primary aerospace vehicle structures of complex geometry, specific detail will be provided after award. The cost to procure and implement the system should be assessed. Quantify the performance of the embedded sensor, corresponding data logging equipment, and the sensor�s impact on the system.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: Work with the Navy to formalize the process for the final design, integration, calibration and/or correlation of the integrated sensors for use to help with the detection of the early failure of parts, which will aid in the reliability of systems and mutually benefits the Navy and aerospace industry. This will include the qualification of the sensing system for use on Navy and aerospace primary and secondary structures.

REFERENCES:

1. Measures, R. "Smart Composite structures with embedded sensors." Composites Engineering, Volume 2, Issues 5-7, 1992. https://www.sciencedirect.com/science/article/pii/0961952692900458.
2. Murukeshan, V., Chan, P., Seng, O. and Asundi, A. "On-line health monitoring of smart composite structures using fiber polarimetric sensor." Smart Materials and Structures, Volume 8, Number 5, 1999. https://iopscience.iop.org/article/10.1088/0964-1726/8/5/303.
3. Kelly, A., Davidson, R. and Uchino, K. "5.20-Smart Composite Materials Systems." Comprehensive Composite Materials, Volume 5, 2000. https://www.sciencedirect.com/science/article/pii/B0080429939009992.
4. Schaaf, Kristin Leigh. "Composite materials with integrated embedded sensing." UC San Diego Electronics Theses and Dissertations. https://escholarship.org/uc/item/0gx2j946.
5. Rathod, Vivek and Deng, Yiming. "Structural compatibility of thin film sensors embedded in a composite laminate." Proc. SPIE 1096728, 2019. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10967/1096728/Structural-compatibility-of-thin-film-sensors-embedded-in-a-composite/10.1117/12.2514393.short?SSO=1.

KEYWORDS: Strategic Missiles; Composite Materials; Health Monitoring; Embedded Sensors; Optical Strain Gauge; Damage Detection