Department of the navy (don) 17. 1 Small Business Innovation Research (sbir) Proposal Submission Instructions introduction

DESCRIPTION: Due to many design and performance advantages, composite materials are used extensively in current submersible applications with plans to increase their use in future submarine platforms such as OHIO Replacement. While the initial design and fabrication expenses of composite structures may be increased from traditional materials, the possibility for significant reductions in maintenance and fuel expenditures while increasing the time of duty will lead to an overall cost benefit. While the benefits of composite materials are obvious, fiber-reinforced polymers are still subject to internal micro cracking and delamination. This internal damage, which typically occurs due to in-service loading such as extended use (fatigue) and abnormal severe conditions (impact), is difficult to detect and repair, and may eventually lead to catastrophic failure. Inspection of in-service composite structures for internal damage is difficult, expensive, and time intensive. Current state-of-the-art inspection techniques for Navy composite structures include gross visual, acoustic (tap testing), and ultrasonic testing (UT). Gross visual inspection is only capable of identifying damage present on the surface of the part. It is also highly dependent on the skill and concentration of the operator to decipher between superficial and structural damage. Acoustic (tap) testing is used to identify locations in the structure where the audible response changes within the laminate field. This change in sound indicates a difference in structural stiffness/damping and may be indicative of internal damage. This method is also highly dependent on the skill and concentration of the operator to identify locations of possible damage. Ultrasonic inspection can identify subsurface damage within a part. However, UT requires trained and certified technicians to operate the inspection equipment and interpret the results. Most often A-scan is utilized, but it is not uncommon to see C-scan. UT can be very time-consuming when considering a probe (transducer/receiver) which is approximately 1-inch in size is scanning a part approximately 50 – 100 sq. ft. or larger. Other non-destructive inspection methods include thermography, shearography, laser interferometry, and x-ray imaging, but these methods are not widely used in the field because of lack of standardized methods or in some instances, practicality. Recently, the Navy has investigated a number of structural health monitoring techniques for submersible composite and other structures. While these monitoring techniques show great promise in their ability to detect damage, due to their cost, these systems may only be suited for structural areas identified as being likely candidates for damage to occur. The goal of this topic is to develop a damage visualization technology capable of being integrated within the composite components, which will allow for rapid, optical identification of any new or growing flaw damage.

The main sources of composite damage are bolted joint strains, fatigue, and direct impact, causing cracking or delamination of the composite material. Shock or even more severe sources of damage should be considered as a possibility. While in service, the ability to visually identify damage by looking at the structure would decrease operational and maintenance costs by reducing the amount of time allotted for tedious inspections and the premature replacement of costly composite structures. Any developed technology must be capable of operating in extreme environments including shock, high vibration (fatigue), high pressures, and a submerged environment. Researchers in the field of self-healing composites have shown the ability to embed encapsulated liquid polymers during fabrication. When the embedded capsule is overstressed, which is engineered to occur when a local composite failure arises, the polymer is released into the damaged region. In self-healing composites, the released polymer interacts with the composite fracture surfaces to help mitigate gross composite failure. An encapsulated polymer approach is one possible solution to including a visual aid into the composite system, but the ability to ‘heal’ damage is not the target application of this topic. Alternatively, a surface treatment approach such as a smart polymeric coating is also acceptable. Any approach that allows for simple, optical identification of the location of a composite flaw or failure through the composite thickness, which does not degrade the designed performance of the composite material, is acceptable.

PHASE I: Develop a concept to enable visualization of damage present in fiber-reinforced polymer composite materials. After identifying an approach to allow for the display of damage in or on a composite, the technical feasibility of the chosen method should be demonstrated on a coupon size composite specimen. Depending on the technology developed, the coupon could be mechanically tested via quasi-static tension, fatigue, impact, bending, or any standard test that will best demonstrate the novel approach, ideally demonstrating the ability to detect flaws through the specimen thickness. In the Phase I Option, if awarded, the company should expand the test to a coupon submerged in water to demonstrate the feasibility of the technique in an underwater environment.

PHASE II: Based on the results of Phase I and the Phase II Statement of Work, the company will expand upon the Phase I work to develop and deliver a representative prototype capable of deployment for damage visualization on an actual submerged structure subjected to representative loading conditions. The structure should be representative of a typical composite submarine component, which is often very thick, utilizing standard materials and fabrication techniques. The structure, with novel damage visualization additions, will then be subjected to cyclic loading and/or thermal gradients to introduce damage in a composite failure mode of interest to the OHIO Replacement program.

PHASE III DUAL USE APPLICATIONS: The company will support the Navy in transitioning the technology to Navy use. If necessary for integration into the composite material, the company will need to work with vendors typically used to construct large Navy composite parts. Ideally, the final product will allow expedited inspections and maintenance of large composite structures. If necessary, the product will need to undergo standard testing (shock and vibration) for integration onto a Navy vessel. Depending on the developed technology, the system may need to be integrated with end user systems and interfaces. The Navy will conduct final experimental testing on actual naval assets. Private Sector Commercial Potential: A number of other applications and industries would benefit from composite damage visualization technology. Composite fatigue failure is a strong candidate to apply this technology since small regions of damage develop and coalesce over time, ultimately resulting in catastrophic failure of the part. Composites are widely utilized in highly fatigued aerospace structures such as airplane bodies and wings that require routine inspection for damage to indicate when to remove these parts from service. Additionally, composite wind turbine blades are susceptible to unknown catastrophic failure and could benefit from a damage visualization technique to help determine the cause of and prevent failure. Finally, commercial shipping and tourism could also benefit from a successfully developed visualization tool to de-service damaged equipment before catastrophic failure occurs.

REFERENCES:

1. Mouritz, A. P., Gellert, E., Burchill, P., and Challis, K., 2001, “Review of Advanced Composite Structures for Naval Ships and Submarines,” Composite Structures, Vol. 53, No. 1, pp. 21-42. http://www.sciencedirect.com/science/article/pii/S0263822300001

2. White, S. R., Sottos, N. R., Geubelle, P. H., Moore, J. S., Kessler, M. R., Sriram, S. R., Brown, E. N., and Viswanathan, S., 2001, “Autonomic healing of polymer composites,” Nature, Vol. 409, pp. 794-797. http://www.nature.com/nature/journal/v409/n6822/full/409794a0.html

3. Wang, Y., Pham, D. T., and Ji, C., 2015, “Self-healing composites: A review,” Cogent Engineering, Vol. 2, No. 1. http://cogentoa.tandfonline.com/doi/full/10.1080/23311916.2015.1075686

4. Vidinejevs, S., Aniskevich, A. N., Gregor, A, Sjöberg, M, and Alvarez, G., 2012, “Smart polymeric coatings for damage visualization in substrate materials,” Journal of Intelligent Material Systems and Structures, Vol. 23, No. 12, pp. 1371-1377. http://jim.sagepub.com/content/23/12/1371.abstract

5. Bar-Cohen, Y., 1986, “NDE of Reinforced Composite Materials—A Review.” Materials Evaluation, Vol. 44, pp. 446-454.

KEYWORDS: Visual Inspection of composites; Composites; Submersible Structures; Damage Detection; Smart Structures; Structural Monitoring; Rapid Inspection of submersibles.

Questions may also be submitted through DoD SBIR/STTR SITIS website.

N171-037

TITLE: Improved Magazine/Armor for Ballistic Performance

TECHNOLOGY AREA(S): Materials/Processes

ACQUISITION PROGRAM: PMS501, Littoral Combat Ships (LCS) Acquisition Program Office

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 5.4.c.(8) 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 innovative mechanical surface treatments for armor systems to improve the ballistic performance of the LCS magazine storage structure to provide an overall weight savings for the ship.

DESCRIPTION: The Navy requires the development of an approach to provide armor protection for vital munitions and personnel spaces onboard the Littoral Combat Ship (LCS). The LCS is limited in the amount of weight that can be dedicated to armor protection due to the small size of the vessel and other requirements such as speed, range, and weight. In order to meet these requirements, the Navy is seeking an innovative lightweight armor system to increase survivability within these constraints.

Currently, the Navy employs the use of external armor panels or increase the thickness of panels to protect valued assets. While it satisfies the need, there is a significant weight penalty added.

A potential technology that addresses this objective is a mechanical surface treatment to improve the ballistic performance of current armor. Mechanical surface treatments such as metal surface hardening and laser peening that would improve the ballistic performance of current armor, allowing for thinner and thus lighter material that would provide for the same level of protection, could substantially improve the capability of the LCS platform.

Use of mechanical surface treatments is not standard in the armor industry. Research into material properties and applicable mechanical treatments that may improve ballistic resistance of armor as measured by the test methods of reference is required. Any methods using chemical surface treatments and/or coatings are not to be considered for this topic.

Companies will be expected to demonstrate an approach that reduces the weight of armor required to stop measured ballistic impacts. References are to be used for guidance in determining the approach. Findings should document weight of standard aluminum, steel or ceramic armor compared to similar weight of each surface treated material required to stop a variety of ballistic impacts. Companies should address impacts to the shipbuilding process, such as hazardous material handling, toxicity concerns or special tooling required, that may substantially increase the cost of armor applied to ships. The process would need to be applicable to new construction ships and to the current fleet.

The Phase II effort will likely require secure access, and NAVSEA will process the DD254 to support the contractor for personnel and facility certification for secure access. The Phase I effort will not require access to classified information. If need be, data of the same level of complexity as secured data will be provided to support Phase I work.

PHASE I: The company will investigate processes and technologies that can achieve the objective. The company will make a feasibility determination that discusses the benefits of mechanical surface treatments on metal in detail, the theoretical and empirical data obtained to support its approach, and a Phase II Statement of Work (SOW) that addresses technical risk reduction and provides performance goals and key technical milestones. The Phase I Option, if awarded, will utilize the completed feasibility study to determine the materials and areas that are most applicable to focus on when building a prototype in the Phase II work.

PHASE II: Based on the results of Phase I and the Phase II Statement of Work (SOW), the company will develop a scaled demonstration model for evaluation and delivery. The demonstration model will be evaluated to determine its capability in meeting the performance goals defined in the Phase II SOW and the Navy requirements. System performance will be demonstrated through ballistic testing of the demonstration model and existing armor materials. Specific focus on the weight required for each material to have the same threshold of survivability against various impacts is needed. These requirements will be supplied once the small business has been approved for access to classified information. Evaluation results will be used to refine the concept into a design that will meet Navy requirements. The company will prepare a Phase III development plan to transition the technology to Navy and potential commercial use.

PHASE III DUAL USE APPLICATIONS: The company will be expected to support the Navy in transitioning the technology for Navy use. The company will further refine a detailed approach for the LCS armor and ammunition magazine that provides the same level of protection as the current system, which will be supplied during the Phase II process. Threshold and objective goals for weight reduction and total cost will be included as part of the effort. The company will support the Navy for test and validation to certify and qualify the system for Navy use. Private Sector Commercial Potential: The potential for commercial use in personnel protection for law enforcement and private security contractors exists. The resulting technology could be utilized for armored vehicles currently in use by security professionals for protection and transport of high-ranking officials. Law enforcement could also utilize the technology on MRAPs and HUMVEEs for urban security operations.

REFERENCES:

1. MIL-STD-662F, Department of Defense Test Method Standard (V50 Ballistic Tests for Armor), dated 18 Dec 1997.

2. MIL-DTL-46027K Detail Specification Armor Plate, Aluminum Alloy, Weldable 5083, 5456, & 5059 dated 31 Jul 07.

3. Showalter, D.D., Placzankis, B.E. & Burkins, M.S. (2008). Ballistic Performance Testing of Aluminum Alloy 5059-H131 and 5059-H136 for Armor Applications, ARL-TR-4427.

4. Doherty, K., et al. (2012). Expanding the Availability of Lightweight Aluminum Alloy Armor Plate Procured From Detailed Military Specifications, ARL-RP-385, 13th International Conference on Aluminum Alloys (ICAA13), pp. 541–546, Pittsburgh, PA, 3–7 June 2012.-

KEYWORDS: Lightweight armor; metal surface hardening; laser peening of metal; ballistic properties of hardened metal; metal surface treatments for strength; Reducing weight of armor protection.

Questions may also be submitted through DoD SBIR/STTR SITIS website.

N171-038

TITLE: Diffractive Optical Element for Light Field Displays (LFDs)

TECHNOLOGY AREA(S): Information Systems

ACQUISITION PROGRAM: PEO IWS 1.0 – AEGIS Combat System

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 5.4.c.(8) 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 a diffractive optical element for light field displays that replaces micro-lens arrays in light field display projection systems.

DESCRIPTION: Light field displays provide the Navy and its operators with a significant capability improvement for perceiving and understanding actionable information from tactical displays during collaboration, instruction, or training. In addition, light field displays provide spatial and perspective accuracy not readily conveyed in conventional two-dimensional (2D) displays. Accurate angular distribution of the 3D radiance image, while still preserving color fidelity over a wide field of view (FoV) is extremely important in maintaining the integrity of the data/imagery being displayed.

A light field can be described as a set of rays that pass through every point in space. A light field radiance image is a raster description of a light field which can be projected through a micro-lens (hogel optics) array to reconstruct a three dimensional (3D) image in space. The light field display offers perspective for the correct visualization with the expected depth cues such as occlusion, gradient shading, and specular highlights for all viewers within the light field projection. It alleviates the need for head or eye tracking or Virtual Reality (VR) headsets.

There are multiple projection technologies available that range from liquid crystal on silicon (LCoS) to laser beam steering (LBS) systems. Refractive optics is used for both the collimating lens and the hogel optic. The integration complexity and manufacturing cost of these optical elements are high. High numerical aperture (NA), large area collimating lenses are difficult to manufacture, especially in large, greater than 1” diameter. High NA (high FoV), micro-lenses are also difficult to mold due to the tight tolerances of each optical element.

For a large area (~1m²), wide FoV (greater than or equal to 90°) hogel optic arrays are complex and expensive multi-element solutions. The Navy seeks diffractive optical element solutions that replace or augment current refractive micro-lens (0.5mm² – 1mm²) hogel optics in order to reduce the cost and complexity of light field display projection systems. The optical requirements for the diffractive hogel optical system will mirror that of a traditional camera lens. Like most camera lenses, the image quality is less than diffraction limited. While Strehl ratios of 1 are desired, they are not necessary; especially in the case of hogel optics as the 3 dimensional circle of confusion is eye limited. This means that the eye’s ability to resolve objects in free space is the limiting factor for any Light field display (LFD) display.

With current manufacturing technologies, the die to mold precision optical elements cost around $20,000 to $40,000 for small molds - less than 2” in diameter - and up to $250,000 for large optical lenslet arrays. For 1m2 arrays, tiling multiple lenslet arrays may be the only option. This will add to the chassis complexity and additional labor during production to align and calibrate. The typical anticipated costs for an optical system will range from $2,000 to $4,000 for a 1m2 array.

The Navy seeks an equivalent optics system with diffractive technology to significantly reduce production cost. Such a system might be based on refractive optical technology, allowing the use of etched diffraction grating patterns on a glass substrate, rather than a tiled array of individually crafted lenses. While the development of an initial print/etch master might be relatively expensive, subsequent use of the master during production runs would result in significant cost reduction on a per unit basis. The proposed solution should reduce the eventual production cost per unit below $1,000. The amortized cost (over 1000 units) of a traditional optical platform is approximately $5,000-$7,000 and thus the anticipated cost reduction of this technology is 5X to 7X. The LFD hogel optic’s performance should yield a pixel spot size of no greater than 2X the pixel extent. For instance, if the pixel yields an angular extent of one degree, the full width at half maximum (FWHM) of the pixel should not exceed two degrees. The associated range of performance of an LFD optic should range from 1 pixel to 2 pixels.

PHASE I: Develop a concept for a diffractive optical element for light field displays to replace traditional micro-lens arrays for large, wide FoV light field display projection systems. The company will demonstrate that its concept is feasible in meeting Navy needs and demonstrate that the concept can be implemented. Feasibility will be demonstrated by some combination of modeling and analysis by exploring concepts of diffractive optics to reduce manufacturing cost. The company will show the solution can be feasibly integrated in place of the current optical elements.

The optical requirements for the diffractive hogel optical system will mirror that of a traditional camera lens. Like most camera lenses, the image quality is less than diffraction limited. While Strehl ratios of 1 are desired, they are not necessary. Especially in the case of hogel optics as the 3 dimensional circle of confusion is eye limited. This means that the eye’s ability to resolve objects in free space is the limiting factor for an LFD display.

The prediction is a Strehl ratio of 0.3 to 0.5 with distortion of less than 1% out to 0.7 FoV will yield a good light field display. The FoV for the system shall be 90 degrees minimum. The Phase I Option, if awarded, should provide the initial layout and product specifications to build the prototype in Phase II.

PHASE II: Based on the Phase I results and the Phase II Statement of Work (SOW), the company will produce and deliver a prototype diffractive optical element for light field displays. Evaluation will be accomplished by laboratory testing of the prototype, accompanied by appropriate data analysis, and modeling. The company will perform the actual testing in consultation with Government subject matter experts to refine parameters and goals. The affordability analysis performed in Phase I will be refined to reflect the knowledge gained during Phase II execution. The company will prepare a Phase III development plan to transition the technology for Navy and potential commercial use.

PHASE III DUAL USE APPLICATIONS: The company will be expected to support the Navy in transitioning the technology to Navy use. The company will further refine a diffractive optical element for light field displays according to the Phase III development plan for evaluation on AEGIS platforms in order to determine their effectiveness and reliability in an operationally relevant environment. The company will perform test and validation to certify and qualify initial production units for Navy use. The final product will be produced by the company (or under license) and transition to the Government. The final product will be a diffractive lens array for a light field display. Private Sector Commercial Potential: There are many applications for micro-lenses. This technology allows for using diffractive optical elements as a micro-lens element instead of traditional refractive technologies. One such example is a vertical-cavity surface-emitting laser (VCSEL) array used in the telecommunication industry.