Solar and Thermal Energy Harvesting Textile Composites for Aerospace Applications

The proposed research focuses on developing novel energy harvesting devices that can be integrated with loadbearing structures in an air vehicle (e.g. a UAV). Several ambient energy sources are available on a UAV: light, heat, and vibration. The amount of energy available from light and heat exceeds that in vibration, so this work focuses on the first two modes of harvesting.

Posted in: Briefs, Materials, Aircraft structures, Solar energy, Heat exchangers, Composite materials, Textiles

Thermo-Elastic Nondestructive Evaluation of Fatigue Damage in PMR-15 Resin

New aircraft are expected to use more composite materials. This drives the need for nondestructive evaluation (NDE) of composite materials. Current aircraft are flown beyond their design lives, and have to be inspected for fatigue and other types of damage. This necessitates a need to understand the NDE signal-material relationship to evaluate the component state.

Posted in: Briefs, Materials, Aircraft structures, Composite materials, Fatigue, Resins, Non-destructive tests

Characterization of Ceramic Composite Materials Using Terahertz Nondestructive Evaluation Techniques

This work describes the use of nondestructive evaluation (NDE) techniques to characterize defects such as rust, voids, etc. in materials, and to analyze and predict strain and stress-induced breakdown. The use of terahertz (THz) imaging as an evaluation tool for novel materials and systems has found much success in recent years. While suggested as a potential NDE tool for use in the field of ceramic and ceramic matrix composite materials, the use of THz spectroscopy and imaging in the examination of the effects of mechanical and thermally induced strain on ceramic composite materials is not well established. In order to assess the effectiveness of THz imaging for use in the analysis of ceramic composite material health, it is necessary to determine if THz spectroscopic imaging can clearly highlight areas of the samples that have been affected by mechanical and thermal stress.

Posted in: Briefs, Materials, Ceramics, Composite materials, Materials properties, Non-destructive tests

High Strain Rate Mechanical Properties of Glassy Polymers

Arange of experimental data has been generated describing the response of glassy polymers to high strain rate loading in compression. Recently, research programs that study the combined effects of temperature and strain rate have made significant steps in providing better understanding of the physics behind the observed response, and also in modeling this response. However, limited data are available in tension, and even more limited are data describing both the compressive and tensile response of the same polymer. In those studies that do examine tensile response, often there are large gaps in the strain rate dependence. These gaps are due to the relative difficulty of performing characterization experiments in tension, especially on polymers and especially at high rates.

Posted in: Briefs, Materials, Materials properties, Polymers, Tensile Strength

Solving the Power/Energy Paradox for High-Power Defense Applications

While often used interchangeably, power and energy are not the same. Energy is the capacity to perform and power is the rate at which that capacity is exercised — the rate at which energy is delivered. When measured, energy is an amount; power is a ratio. In relation to energy storage, a common misconception is that the larger the quantity of stored energy, the higher the potential rate of power. In fact, the opposite is true, rendering the following principles wholly counterintuitive to those unfamiliar with the nuanced mechanics of energy storage: when less energy is stored, a system is capable of producing high power and conversely, when more energy is stored, a system is capable only of producing low power. As a result, engineers are presented with a challenge in the manufacture of energy storage systems for highpower mobile applications with the highest energy density possible. In pursuit of this goal, modern research into lithium ion (Li-ion) electrochemistries is proving very promising.

Posted in: Articles, Aerospace, Battery cell chemistry, Capacitors, Energy storage systems, Lithium-ion batteries, Electric power

The Role of Engineering Simulation in the Evolution of Unmanned Aircraft Systems

Across all domains (land, sea, and air), the use of unmanned aircraft systems (UASs) has shown explosive growth and, as their value continues to be demonstrated, this growth shows no sign of slowing. However, the UAS industry must address a number of key challenges if it is to satisfy the future roadmap for UAS development and deployment outlined by its major client, the U.S. Department of Defense (DoD). These challenges include:

Posted in: Articles, Aerospace, CAD / CAM / CAE, Defense industry, Systems engineering, Unmanned aerial vehicles

Optimizing High Reliability Power Distribution System Designs

As the performance requirements of avionics, military, and space electronic systems increase, so do the demands on the power supplies for these systems. Successful system designs demand the power distribution architecture be optimized for maximum efficiency with a minimum size and weight. Power system cost and development schedule must also be taken into consideration. One possible solution is to develop a custom power supply that meets all of the system load requirements. The downsides of this approach include long development time, high non-recurring engineering costs, and system flexibility limitations. Additionally, should the load specifications change during system development, then the power supply will need to be redesigned to accommodate changes, incurring even more time and cost.

Posted in: Articles, Aerospace, Architecture, Avionics, Electronic control systems, Systems engineering

Wireless Power via Laser

Technology from LaserMotive (Kent, WA) converts electricity to light using lasers, and projects that light onto a specialized solar cell array, which then converts the light back into electricity. The “wireless extension cord” delivers thousands of watts at ranges up to many kilometers.

Posted in: Application Briefs, Lasers, Electric power

Vertical Take-Off and Landing UAV

The Air Force has announced that the MLB V-Bat Vertical Take-Off and Landing (VTOL) UAV from the MLB Company (Sunnyvale, CA) has been selected for a Phase II SBIR award. The military branch seeks a vehicle that has an 8-ft wingspan, 10-hour endurance, 55-lb gross take-off weight, and 70-mph cruise speed. The V-Bat’s combination of VTOL operational convenience with the safety of a shrouded fan and fixed-wing duration in a small UAV system will enable local situational awareness for UAV operations in confined areas. Last year, under a DARPA contract, MLB demonstrated precise emplacement of small payloads from the V-Bat, operating in hover mode under a vision-based control system.

Posted in: Application Briefs, Military aircraft, Unmanned aerial vehicles

Electronics Authentication Program

To deal with the crisis of counterfeit electronics flooding into the US defensesupply chain, the Defense Logistics Agency (DLA), a procurement and supply arm of the U.S. Department of Defense, is considering a mandate requiring defense contractors to use the authentication services of Stony Brook, NY-based Applied DNA Sciences (APDN). If a mandate goes into effect, DLA would require contractors to implement APDN’s SigNature® DNA marking program for microcircuits provided to the military. Defense contractors would have to prove that their microcircuits are marked with SigNature DNA.

Posted in: Application Briefs, Counterfeit parts