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

DESCRIPTION: Full-scale fatigue testing is performed to evaluate entire aircraft structures for durability and to ensure they can meet their design life without catastrophic failure occurring. In flight, helicopter airframes are subjected to a superimposed combination of vibratory and maneuver loads. The vibratory loads, induced by rotor head dynamics, produce upwards of a billion cycles of loading and are thus termed High Cycle Fatigue (HCF) loads. The maneuver and ground loads, termed Low Cycle Fatigue (LCF) loads, occur at significantly lower cycle counts (~104), but at higher stresses. The resulting effect of combined loadings is that HCF cycles grow the micro cracks that are initiated by the higher LCF loads, and the fatigue life is synergistically reduced.

Mechanical shakers and hydraulics were used to simulate vibration (primarily HCF loads) for a given flight segment CH-53A, but this test did not apply aerodynamic and maneuver loads, which are both significant LCF loads. The H-3 helicopter underwent a similar full-scale fatigue test. Both of these platforms suffered from significant structural cracking in the pylon fold-hinge bulkheads later in the lifecycle of the aircraft, despite there being no cracks observed in those areas after the full-scale fatigue tests. More recently, due to program test time constraints, HCF loads have been either: truncated analytically (based on the endurance limit of a material) from the test spectrum of full-scale fatigue tests, resulting in pure LCF loading; or accelerated, as on the V-22, by reducing cycle counts and increasing load to apply “equivalent damage”. However, evidence exists that shows that HCF loads below a material’s fatigue endurance limit do affect the life of a structure significantly [Refs 1, 2]. Furthermore, the crack growth threshold stress intensity is reduced at the higher stress ratios (R-ratios), which are typical for these combined loads [Refs 2, 3], making accelerated HCF loads unrepresentative when considering crack growth.

Previous work in combining HCF and LCF loads for full-scale fatigue tests (mixed-mode testing) has been accomplished by the Australian Defense Science and Technology Organization (DSTO). DSTO performed a full-scale fatigue test on an F-18 aft fuselage where they simultaneously applied aerodynamic and maneuver loads with vibratory buffet loads to the stabilators and vertical tail [Ref 4]. From this testing, they were able to successfully replicate cracks on the F-18 vertical tail that were found in service by the U.S. Navy and that were missed by the fatigue analysis and previous tests. This test could be replicated on any other aircraft, including rotary wing platforms. However, this test was time consuming, taking five years to complete, and mechanically complex with several types of custom-built actuators and custom control systems [Ref 4, 5].

Hence, a need exists for improved mixed-mode fatigue testing to accurately assess aircraft structures for durability. An innovative testing system to apply and control HCF and LCF loads simultaneously to a rotary wing aircraft is sought. This “Hybrid Fatigue Testing” would need to utilize multiple existing technologies (advanced hydraulics, electromechanical shakers, pneumatic airbags, etc.) to induce proper vibratory loads into a structure. The resulting testing capability must be standardized, provide accurate loading conditions in a cost-effective manner, and does not significantly increase the duration of a typical full-scale fatigue test (8-12 months). It is preferred that the HCF loads be applied at the rotor “1/rev” frequencies so that they can be balanced by structural inertia as on an aircraft in flight. Preliminary testing results will need to be compared with existing stress-life (SN) and strain-life (EN) methodologies, in addition to existing test data. The ultimate objective is to utilize this methodology to perform mixed-mode fatigue testing of full scale aircraft and aircraft components. Since the results would be more realistic, mixed-mode fatigue testing would allow for a traceable reduction in conservatism, resulting in weight savings, while maintaining structural safety. Mixed-mode fatigue testing would also expose more representative fatigue problems airframes early in the life of an aircraft could potentially reduce future unscheduled maintenance.

PHASE I: Develop a method and tool to apply simultaneous HCF and LCF loads to a sample structure, such as a joint or a beam, using a limited number of loading devices (actuators, electromechanical shakers, etc.) and demonstrate the feasibility of the proposed technology. Include a plan to scale this technology to multiple channels of controlled loading. Demonstrate the feasibility of the approach in a laboratory environment.

PHASE II: Develop a prototype hybrid fatigue testing system (hardware, software, and operating standards), based on Phase I efforts. Perform hybrid fatigue tests (1-Degree or 2-Degree loads) on a structural feature (e.g., a joint or beam) using the prototype test system. Compare the results to traditional analysis (based on SN and EN fatigue methodologies) and test data, which will be provided by NAVAIR.

PHASE III DUAL USE APPLICATIONS: Using the hybrid fatigue testing system developed in Phase I and Phase II perform testing on a helicopter airframe or other large aircraft structure to a realistic spectrum of HCF and LCF spectrum loads to validate its structural durability under a combined loads spectrum. Incorporate any necessary changes into the test systems based upon the outcome of full-scale testing. Incorporate the final test systems into the qualification and certification testing of commercial helicopters and other potential fixed and rotary wing platforms that could benefit from the technology. Private Sector Commercial Potential: Similar to naval aircraft, commercial aircraft experience fatigue, which can culminate in cracks and lead to complete fracture after a sufficient number of load cycles. Structural deterioration in aging aircraft increases the maintenance workload, reduces aircraft readiness, and potentially increases safety risks. A system of more accurately loading aircraft for both HCF and LCF is necessary to accurately assess aircraft structures would be beneficial for commercial aircraft.

REFERENCES:

1. Sonsino, C. M. (2007). “Course of SN-curves especially in the high-cycle fatigue regime with regard to component design and safety.” International Journal of Fatigue Vol. 29, 2246–2258. http://www.sciencedirect.com/science/article/pii/S014211230600346X

2. Stanzl-Tschegg, Stefanie. (2014). “Very high cycle fatigue measuring techniques.” International Journal of Fatigue Vol. 60, 2-17. http://www.sciencedirect.com/science/article/pii/S0142112312003581

3. Halford, G. R. (1997). “Cumulative fatigue damage modeling—crack nucleation and early growth.” International Journal of Fatigue Vol. 19, Issue 93, 253–260. http://www.sciencedirect.com/science/article/pii/S0142112397000480

4. Conser, D.P., Graham, A.D., Smith, C.J., & Yule, C.L. “The Application of Dynamic Loads to a Full Scale F/A-18 Fatigue Test Article.” Aeronautical and Maritime Research Laboratory. ICAS 96. http://www.icas.org/ICAS_ARCHIVE/ICAS1996/ICAS-96-5.10.5.pdf

5. Molent, L. “The History of Structural Fatigue Testing at Fishermans Bend Australia.” DSTO-TR-1773. Air Vehicles Division, Defense Science and Technology Organisation. http://www.dtic.mil/dtic/tr/fulltext/u2/a441814.pdf

KEYWORDS: Fatigue; Test; Vibration; Structure; Helicopter; Durability

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

N171-028

TITLE: Lightweight Self-Start System for T56 Engine Driven Aircraft

TECHNOLOGY AREA(S): Air Platform

ACQUISITION PROGRAM: PMA 231 E-2 Acquisition Program Office

OBJECTIVE: Identify and develop small, self-contained, lightweight system for starting E-2D T56 engines and allow for remote field operations.

DESCRIPTION: The E-2D currently has a deficiency in that it is difficult to operate in remote areas due to a lack of an on-board engine starting system. Currently, the E-2D’s gross weight and internal volume restrict significant additions to the aircraft. In addition, anticipated future requirements make the demands on minimizing additions to weight or internal volume even more critical. Current requirements for the E-2D T-56 engine require special support equipment (Huffer cart) to generate the necessary 168 ft-lb of torque at a rotation speed of 8000 RPM to start the engine (Ref 1). Current technology has starter power plants that weigh approximately 150-200 lbs and when fully integrated on the aircraft can add over 400 lbs to the aircraft. Although a remote field starting capability is desirable for the E-2D, it cannot allocate this much weight to the engine start system. An innovative self-start solution that can capture the reduced weight and space requirements while maintaining starter performance is sought.

When designing a starter system, weight and volume need to be reflected as a fully integrated unit. The starter unit is not required to do anything other than start the aircraft engines on the ground. The starter should fit into a space approximately 11”L x 8”W x 10”H. If additional volume is needed, there is a second space of approximately the same size further aft on the engine. In addition, it is desired that the entire starter system should weigh under 200 lbs. This maximum weight and volume must take into account the power plant as well as all associated items such as exhaust port, battery system and electrical wiring and charging devices, controller, fire extinguishing system, and mechanical connection between starter and aircraft engine.

PHASE I: Develop and demonstrate the feasibility of an initial design that addresses the technology and design mechanics required to meet the requirements for E-2D aircraft self-start system. Consider practical candidate starter solutions and address/compare performance, cost, and schedule of candidate solutions (Ref 2).

PHASE II: Develop and deliver a E-2D aircraft prototype starter system and demonstrate technology in a representative environment. A representative environment would simulate the interfaces and operating conditions under which the starter system would be expected to perform. This may be a lab environment using a test rig and dynamometer or installed and run on a full-scale engine test cell. Prepare a product specification document and associated costs and schedule for the development and manufacture of the production representative starter unit.

PHASE III DUAL USE APPLICATIONS: Deliver a production representative starter system that can be integrated onto an E-2D aircraft platform for aircraft-level testing. Testing and refinement of the final design system should consider commercial platforms. Private Sector Commercial Potential: A small lightweight aircraft starter system has potential commercial/dual-use in applications in the civilian aviation industry. Any system that minimizes weight and size will provide the aviation industry with options for reducing weight in current or future aircraft.

REFERENCES:

1. MIL-S-19557/6 (AMENDMENT 1), “MILITARY SPECIFICATION SHEET: STARTER, AIRCRAFT ENGINE, AIR TURBINE MODEL A-24 (11-AUG-1983).” Retrieved from http://everyspec.com/MIL-SPECS/MIL-SPECS-MIL-S/MIL-S-19557_7_38515everyspec.com.

2. E-2D Self-Starter Study Results, 6 October 2016, updated 5 January 2017 (document posted in SITIS on 1/6/17).

KEYWORDS: Self-Start; Remote; Lightweight; Small; T-56; E-2D

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

TECHNOLOGY AREA(S): Air Platform, Ground/Sea Vehicles, Sensors

ACQUISITION PROGRAM: PMA 268 Navy Unmanned Combat Air System Demonstration

OBJECTIVE: Develop a sensor(s) that accurately senses the relative motion between a slow moving unmanned vehicle and the deck of a ship.

DESCRIPTION: A sensor(s) capable of accurately tracking low speed velocity measurements (TVM) of slow moving unmanned vehicles on Navy carrier decks, such as CVN, LHA, and LHD, is sought. The TVM sensor must be able to operate in the maritime operational environments spanning from the North Atlantic to the tropics with sea states up to 5 [Ref 1], with rain, snow, ice and fog.

An aircraft, taxiing under its own power on the flight deck of a ship, may not always move in the commanded direction. Deck conditions, such as fluid on the deck, worn non-skid deck material or the motion of the ship, could cause the aircraft to slide or skid. Unmanned vehicles require the ability to determine true direction and speed of motion relative to the deck to allow for detection of and reaction to sliding or skidding and/or to initiate appropriate emergency response if required.

It is not adequate to simply count the rotation of the wheels in the direction of the steering gear, as skidding or sliding may not be in the commanded direction of motion. The operator of an unmanned vehicle may not be able to recognize and compensate for uncommanded and unexpected vehicle motion quickly enough to prevent a mishap.

The sensor(s) solution needs to provide accurate deck relative velocity measurement for normal taxi (roughly up to 6 mph) and creeping (roughly up to 0.7 mph, i.e. during alignment at the catapult), as well as skid/slip emergency situations.

Global Positioning Systems (GPS) or pure inertial systems are not sufficient due to conditions on a rolling/heaving deck. The aircraft controller must know the vehicle direction, not merely detect loss of traction. Automotive off-the-shelf systems would not be sufficient due to the adverse effects of ship deck motion. Existing off-the-shelf wheel revolutions per minute (RPM) measurement systems are insufficient due to frequent aircraft tire slippage during taxiing operations.

The TVM sensor will become part of the unmanned vehicle control system allowing it to detect and react to uncommanded motion for safe operations on the dynamic and sometimes unpredictable carrier flight deck. The final sensor solution needs to have the capability for self-monitoring and to be integrated with the vehicle control system in a manner such that the solution itself does not have failure modes that will cause uncommanded motion.

The final sensor system is envisioned for Group 4 and 5 unmanned air vehicles (UAV). [Ref 2]

PHASE I: Design, develop and demonstrate feasibility of theoretical methods for determining vehicle motion relative to the deck of a ship. Develop block and logic diagrams of proposed system, and analytically demonstrate how the sensor(s) would work. Provide size / weight / power analysis along with the system definition so that the Navy has an understanding of the relation of the TMV sensor to Group 4 and 5 [Ref 2] UAV/ship interface requirements.

PHASE II: Develop a prototype version of the sensor(s), including any software required. Prove by technical demonstration in a laboratory setting that the sensor(s) accurately track and perform velocity measurements of slow moving unmanned vehicles as if on board a carrier deck. Prototypes do not have to meet all military requirements, e.g. rugged environment (MIL-STD -810) testing for Phase II. Identify the data required for successful tracking of relative motion.

Prepare a Phase III plan to refine the design for the sensor(s) and build three prototypes close to actual (production) size and weight. Include military environments in the requirements for future development in Phase III. Investigate commercial applications.

PHASE III DUAL USE APPLICATIONS: Complete development, refine prototype(s) that meet military environment requirements and operationally demonstrate on a taxiway (shore base) integrated with a surrogate government provided ground vehicle. The Navy has a surrogate ground vehicle for experimentation at Lakehurst NJ, details to be provided during Phase II. Implement the sensor into the Navy recommended UAV’s control system, targeted UAV to be provided during Phase II. Continue researching and development for commercial applications, such as warehouse distribution centers. Private Sector Commercial Potential: This technology could also be applied to shore based aircraft operating in hazardous weather conditions and ground vehicles such as tow tractors or motorized dollies. This may be useful for unmanned stocking and picking vehicles at large warehouse distribution centers.

REFERENCES:

1. Designing Ships to the Natural Environment, Susan Bales, DTNSRDC, April 1982. (Document uploaded to SITIS on 11/30/16.)

2. Department of Defense, March 2011, Unmanned Aircraft System Airspace Integration Plan, Version 2.0. Retrieved from http://www.acq.osd.mil/sts/docs/DoD_UAS_Airspace_Integ_Plan_v2_(signed).pdf

3. MIL-STD-810G, April 2014 (Change-1). Environmental Engineering Considerations and Laboratory Tests. Retrieved from http://www.atec.army.mil/publications/Mil-Std-810G/Mil-Std-810G.pdf.

4. MIL-STD-461G, 11 December 2015. Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment. Retrieved from http://everyspec.com.

KEYWORDS: Unmanned Air Vehicle; Unmanned ground vehicles; autonomy; Sea-Based Aviation; robotics; deck operations

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

N171-030

TITLE: Dual Chaff Air Expendable Decoy Device

TECHNOLOGY AREA(S): Air Platform, Battlespace, Weapons

ACQUISITION PROGRAM: PMA-272, Tactical Aircraft Protection Systems

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: Design and develop a dual chaff air expendable decoy device consisting of a dual impulse cartridge and a payload casing system. No development is required for the chaff payload itself.

DESCRIPTION: Recent improvements for payload output, configuration, and particle sizes (via multiple US Air Force, US Army, and US Navy projects) have resulted in improved efficiency and performance of payloads in Air Expendable Countermeasure Decoys. In order to take advantage of these gains, design and development of an innovative compact dual impulse cartridge and the associated dual chaff payload casing system resulting in a dual air expendable chaff decoy is sought. A dual impulse cartridge should be capable of utilizing a single firing circuit and provide for two (2) separate payload initiations sequentially at two (2) different firing times as needed. The dual impulse cartridge should be designed for use in the AN/ALE-47 Countermeasures Dispensing System (CMDS) and should fit in the standard Navy round form factor of 1.42 inches in diameter and 5.84 inches in length. The AN/ALE-47 CMDS will provide a nominal 28 volt firing pulse at up to five amperes current. The dual impulse cartridge should be designed to meet the programming capabilities of the ALE-47 Countermeasure Dispensing System. A combined unit cost of both the dual casing and dual impulse cartridge of $20.00 or less is desired on a large production volume of 50,000 units per year.

Short ignition delay (15ms), open circuit after ignition (>500 Ohms), low flash (less than 33 foot-candles at 1 foot distance), polling capable circuitry (250 mA), safe Hazards of Electromagnetic Radiation to Ordnance (HERO) (MIL-STD-464) rating, and compatibility with the existing AN/ALE-47 CMDS hardware and software are the most desired characteristics of the impulse cartridge.

Successful development of this technology will increase the number of expendable countermeasures dispense events without modifying the existing airframe structure and will increase the aircraft survivability from RF missile threats. The innovation of the design will be to integrate two separate firing pulses into a single point electronic firing system using a low and high voltage supply. The innovation of the design will expand the current chaff dipole design to a finer substrate material to provide the same aircraft cross-section coverage in half the volume.

PHASE I: Design and demonstrate the feasibility for the development of a dual countermeasures impulse cartridge and casing system. Feasibility demonstration should outline the functional characteristics of the dual impulse cartridge and case, and should detail the interoperability of the dual impulse cartridge and case to the ALE-47 CMDS.

PHASE II: Fabricate and demonstrate a functional prototype dual countermeasures impulse cartridge and casing system. Perform testing and make improvements based upon test results. The cartridge and casing design should be optimized for maximum payload carrying capability.

PHASE III DUAL USE APPLICATIONS: Deliver a testable quantity (approximately 200 full up rounds) of dual impulse cartridges and casings for government evaluation and testing. The dual impulse cartridge design should demonstrate a functional reliability of 95% at a 95% confidence level at the completion of Qualification tests and be designed to meet MIL-D-21625 and MIL-DTL-23659. Transition the developed technology to PMA 272 for fielding on appropriate platforms. Private Sector Commercial Potential: Commercial aircraft may have a requirement for a reliable and cost-effective countermeasure against ground to air threats. Development of dual dispensing countermeasure configurations could be utilized by commercial, private, and other government agency aircraft, if equipped with ALE-47 CMDS. Other uses could include ejection seats, firearms ejection, or emergency survival equipment.

REFERENCES:

1. ALE-47 Data Sheet. BAE Systems. http://www.baesystems.com/en-us/product/ale47-airborne-countermeasures-dispenser-system

2. Schelher, Curtis. “Electronic Warfare in the Information Age” (Chapter 7, Expendables and Decoy Systems). Artech House, 1999

3.Schetz, Joseph A., Editor. “The Fundamentals of Aircraft Combat Survivability” (Chapter 4, Susceptibility, Paragraph 4.4.5.1, Radar Expendables). American Institute of Aeronautics and Astronautics, 2003

4. AN/ALE-47 Countermeasures Dispenser System (CMDS), http://www.globalsecurity.org/military/systems/aircraft/systems/an-ale-47.htm

5. MIL-STD-464C, Department of Defense Interface Standard: Electromagnetic Environmental Effects, Requirement for Systems (01 DEC 2010). Available for download at http://everyspec.com/MIL-STD/MIL-STD-0300-0499/MIL-STD-464C_28312

6. MIL-D-21625G, Military Specification: Design and Evaluation of Cartridges for Cartridge Actuated Devices (30 Nov 1993). Available for download at http://everyspec.com/MIL-SPECS/MIL-SPECS-MIL-D/MIL-D-21625G_9064