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Facial recognition software (FRS) is a form of biometric security that detects a face, analyzes it, converts it to data, and then matches it with images in a database. This technology is currently being used in vehicles for safety and convenience features, such as detecting driver fatigue, ensuring ride share drivers are wearing a face covering, or unlocking the vehicle. Public transportation hubs can also use FRS to identify missing persons, intercept domestic terrorism, deter theft, and achieve other security initiatives. However, biometric data is sensitive and there are numerous remaining questions about how to implement and regulate FRS in a way that maximizes its safety and security potential while simultaneously ensuring individual’s right to privacy, data security, and technology-based equality.

Minimizing the stress concentrations around cutouts in a plate is often a design problem, especially in the Aerospace industry. A problem of optimizing spatially varying fiber paths in a symmetric, linear orthotropic composite laminate with a cutout, so as to achieve minimum stress concentration under remote unidirectional tensile loading is of interest in this study. A finite element (FE) model is developed to this extent, which constraints the fiber angles while optimizing the fiber paths, proving essential in manufacturing processes. The idea to be presented could be used to derive fiber paths that would drastically reduce the Stress Concentration Factor (SCF) in a symmetric laminate by using spatially varying fibers in place of unidirectional fibers. The model is proposed for a four layer symmetric laminate, and can be easily reproduced for any number of layers.

Discuss the basics of posturing and positioning of the full range of occupants necessary to cover the required anthropometric demographics in combat vehicles, both ground and air, since there are similarities to both and that they are both very different than the traditional automotive packaging scenarios. It is based on the Eye Reference Point and the Design Eye Point. Discuss the three Reach Zones: Primary, Secondary and Tertiary. Discuss Vision Zones and potentially ground intercepts. Discuss body clearances, both static and dynamic. Discuss the basic effects of packaging occupants with body armor with respect to SRP's and MSRP's.

On September 30, 2011, certification authorities released Advisory Circular 20-174[1], Development of Civil Aircraft and Systems, which recognizes the Society of Automotive Engineers (SAE) Aerospace Recommended Practice (ARP) 4754A and the European equivalent ED-79A [2], in order to address “the concern of possible development errors due to the ever increasing complexity of modern aircraft and systems.” ARP4754A/ED-79A describes a process of development assurance which helps reduce the risk of design errors in the development of aircraft systems. This process is necessary for complex systems not easily comprehended by deterministic analyses or tests. This ARP was developed “in the context of Title 14 of the Code of Federal Regulations (14 CFR) part 25,” a category which includes complex systems such as full fly-by-wire flight controls. However, this paper shows that such systems are the exception to most, recent civil airplane designs.

The Energy Finite Element Analysis (EFEA) has been utilized successfully for modeling complex structural-acoustic systems with isotropic structural material properties. In this paper, a formulation for modeling structures made out of composite materials is presented. An approach based on spectral finite element analysis is utilized first for developing the equivalent material properties for the composite material. These equivalent properties are employed in the EFEA governing differential equations for representing the composite materials and deriving the element level matrices. The power transmission characteristics at connections between members made out of non-isotropic composite material are considered for deriving suitable power transmission coefficients at junctions of interconnected members. These coefficients are utilized for computing the joint matrix that is needed to assemble the global system of EFEA equations.

Understanding reliability is critical in design, maintenance and durability analysis of engineering systems. A reliability simulation methodology is presented in this paper for vehicle fleets using limited data. The method can be used to estimate the reliability of non-repairable as well as repairable systems. It can optimally allocate, based on a target system reliability, individual component reliabilities using a multi-objective optimization algorithm. The algorithm establishes a Pareto front that can be used for optimal tradeoff between reliability and the associated cost. The method uses Monte Carlo simulation to estimate the system failure rate and reliability as a function of time. The probability density functions (PDF) of the time between failures for all components of the system are estimated using either limited data or a user-supplied MTBF (mean time between failures) and its coefficient of variation.

This research paper addresses the ground vehicle reliability prediction process based on a new integrated reliability prediction framework. The integrated stochastic framework combines the computational physics-based predictions with experimental testing information for assessing vehicle reliability. The integrated reliability prediction approach incorporates the following computational steps: i) simulation of stochastic operational environment, ii) vehicle multi-body dynamics analysis, iii) stress prediction in subsystems and components, iv) stochastic progressive damage analysis, and v) component life prediction, including the effects of maintenance and, finally, iv) reliability prediction at component and system level. To solve efficiently and accurately the challenges coming from large-size computational mechanics models and high-dimensional stochastic spaces, a HPC simulation-based approach to the reliability problem was implemented.

The Energy Finite Element Analysis (EFEA) has been developed for evaluating the vibro-acoustic behavior of complex systems. In the past EFEA results have been compared successfully to measured data for Naval, automotive, and aircraft systems. The main objective of this paper is to present information about the process of developing EFEA models for two configurations of a business jet, performing analysis for computing the vibration and the interior noise induced from exterior turbulent boundary layer excitation, and discussing the correlation between test data and simulation results. The structural EFEA model is generated from an existing finite element model used for stress analysis during the aircraft design process. Structural elements used in the finite element model for representing the complete complex aircraft structure become part of the EFEA structural model.

Advanced chemistry batteries may help reduce weight and increase aircraft performance. Lithium Ion chemistries' high energy density enables 40% weight savings over existing baseline, Lead Acid and Nickel-Cadmium (Ni-Cd) batteries. Baseline requirements for Lithium Ion batteries were developed by studying Cessna's aircraft product line. Nanoscale phosphate-based Lithium Ion cathodes improve safety through inert failure modes, while delivering higher power over conventional oxide-based Lithium Ion and baseline chemistries. Cells and batteries were tested under selected load, environmental, and temperature conditions using procedures adapted from RTCA DO-293 and DO-160. On-board aircraft testing verified performance compatibility. Safety tests verified inert failure mode and flight environment compatibility. Test results showed nanoscale phosphate Lithium Ion batteries are promising as a safe, high power Lithium Ion main battery in general aviation aircraft.

This paper describes modeling and simulation technologies used to simulate the electrical systems of Army vehicles using Matlab/Simulink coupled with graphical user interface software. The models were built using Mathworks' Matlab/Simulink software in conjunction with the SimPowerSystems Toolbox, a toolkit provided by Mathworks that provides models of basic electrical components such as capacitors and inductors, in addition to more advanced components such as diodes and IGBT's. The current results of this ongoing effort are presented and discussed.

The current system requirements for the power management subsystem and ground combat vehicles for the Future Combat System require higher power and voltages for greater energy efficiency, advanced mobility, lethality and survivability. Efficient and reliable electrical power management is an essential capability within current force ground combat vehicles and will become even more important with the increased electrical power demands of future force vehicles which will exceed the capabilities of onboard power generation/storage technologies. This paper describes how to meet the aforementioned power distribution challenges through the development of a power management software interfaces standard that will provide the flexibility required by various programs and vehicles yet still provide a consistent framework for software development providing a consistent environment for all future Army programs.

In the aircraft industry, hydroforming is widely used to form parts using aluminum alloys in tempered condition T-XXXX. Success of this process depends on accurate springback prediction. The magnitude of springback and its variation is high in aluminum alloys in tempered condition T-XXXX. Process and material variability causes variation in springback. Wide range of pressures and press types in hydroforming process attribute to process variability. Forming pressures can be varied to control springback. This study looks at the effect of forming pressure on springback in hydroforming of aluminum alloy 2024-T3 and 2524-T3 in two most popular industrial hydropresses. The study forms the basis for developing a new model for springback prediction in the future.

Forming of aluminum sheets in O-temper is a very common industrial process in the aircraft industry. However, the success of this process largely hinges on the ability to predict springback accurately. Aluminum sheets in T-temper exhibit approximately twenty percent variability in material properties and also the amount of springback is very large. This makes tool design for aluminum in T-temper an iterative and difficult to control process. Traditionally aluminum has been formed in the O-temper and then heat-treated to T-temper, as recourse to reduce springback. This research is aimed at developing a predictive finite element technique for springback, using experimental validation. A parametric study was conducted to determine the influence of geometric parameters and tempers on springback. The study characterizes springback of aluminum in different tempers and investigates the effect of forming strain-rates on springback.

Global warming concerns are stimulating accelerated research and development of alternative fuels and propulsion systems for automobiles. The potential application of these emerging technologies to airplanes is reviewed. Preliminary designs of zero greenhouse gas emission airplanes using hydrogen fuel and either internal combustion or fuel cell-electric motor propulsion are presented for a wide body jet transport, medium jet transport, business jet, and single engine propeller airplane. The hydrogen fueled internal combustion engine airplanes offer the easiest path to zero emissions, but the greater efficiency of the fuel cell airplanes allows designs requiring substantially less fuel. The single engine propeller airplane is the easiest to modify for hydrogen fuel, because of the relatively high mass and volume of the engine being replaced. Technology improvements needed to make zero emission airplanes viable are suggested.

Certification of climb performance has traditionally been accomplished using reciprocal heading climbs. This was done to eliminate wind gradient effects. However, the FAA allows climb certification to be done on a single heading when inertial methods are used. A method was developed utilizing a DGPS system that allows an engineer to apply the inertial corrections to a single climb without the need of INS equipment. This method has been validated on several aircraft by comparing conventional reciprocal heading climb results to results obtained using the GPS method on the same climbs. The GPS climb method presented here can potentially reduce the number of climbs required for development and certification as well as provide more consistent data.

A method is presented here that detects aircraft tail surface icing that might normally be unobserved by the flight crew. Such icing can be detected through the action of highly computationally efficient signal processing of existing sensor signals using a so-called failure detection filter (FDF). The FDF creates a unique output signature permitting relatively early detection of tail surface icing. The FDF incorporates a stable state estimator from which the icing signature is created. This estimator is robust to analytical modeling errors or uncertainties, and to process noise (e.g. turbulence). Excellent performance of the method is demonstrated via simulation.

During this study, a number of 8.5-inch by 11.5-inch flat honeycomb sandwich panels were inflicted with low energy impact damage, inspected non-destructively, and tested for residual in-plane compressive strength. Each panel had either a 3/8-inch or 3/4-inch low density Nomex honeycomb core, and either 2-ply, 4-ply or 6-ply face sheets. The face sheets were either carbon or Eglass (prepreg) fabric. The panels were either clamped or simply supported in a test fixture during impact from a gravity assisted drop mechanism, and impacted with either a 1-inch or 3-inch diameter spherical indenter. After impact the damage to each panel was characterized by (1) ultrasonic through-transmission to obtain a c-scan representing planar damage area, (2) indentation volume and depth, and finally (3) visual inspection to rate the damage according to a predetermined rating scale. The panels were then tested for in-plane compressive strength.

Aircraft electromagnetic protection has always been focused on the design, test and analysis required for certifying aircraft. That focus is now expanding to include the continued airworthiness of electromagnetic protection over the entire life of the aircraft. A better understanding of the scope and magnitude of maintaining assurance is needed for continued electromagnetic protection and safety over the lifetime of the aircraft. Wire bundle shielding of aircraft wiring harnesses, electrical bonding, and grounding are all used to provide electromagnetic protection in general aviation aircraft. The effectiveness of these protection methods is assumed to be maintained using periodic detailed visual inspections and DC bond checks after any replacements or repairs. This assumption appears valid because of the low number of catastrophic occurrences involving lightning strikes.

This paper discusses how CATIA solid models of a landing gear system, combined with a NASTRAN flexible model of the aircraft are simulated using CATDADS and DADS to predict the dynamic response, loads, and general design factors for the aircraft and associated landing gears. Several landing gear design factors are predicted and quantified using DADS and CATDADS to solve the 3D nonlinear equations of motion. Position, velocity, acceleration, and gear loads are analytically determined and used to compare to physical tests. Aircraft loads due to symmetric landing and taxi conditions as well as asymmetric landing conditions are analytically determined using a full flexible aircraft model coupled with the landing gears.

Multiple site damage (MSD) on aging aircraft accumulates from fatigue loading over a period of time. For ductile materials such as 2024-T3 aluminum, MSD may lower the strength below that which is predicted by conventional fracture mechanics. An analytical model referred to as the linkup (or plastic zone touch) model has previously been used to describe this phenomenon. However, the linkup model has been shown to produce inaccurate results for many configurations. This paper describes several modifications of the linkup model developed from empirical analyses. These modified linkup models have been shown to produce accurate results over a wide range of configurations for both unstiffened and stiffened flat 2024-T3 panels with MSD at open holes. These modified models are easy to use and give quick and accurate results over a large range of parameters.