Braden T. Lusk, Kyle A. Perry, Joshua M. Hoffman
This paper introduces and describes field tests performed with aluminium mesh. The paper also describes a simple theoretical model created in ANSYS AUTODYN to predict the behaviour of the mesh. This is the third, and final, paper in a series which has characterized aluminium mesh and its blast mitigation properties. Despite its porous and lightweight characteristics, aluminium mesh has been found to have blast mitigation properties. The current use of the mesh includes fuel tanks for airplanes, boats, and fuel stations as well as light armoured vehicles for the military. The mesh acts as an explosion suppressant by preventing fuel tanks from exploding when exposed to an ignition source. More recently, work has been performed to assess the ability of the mesh to mitigate blast pressures produced by high explosives. Nearly 100 tests were conducted over a one-year time period using high explosives. The first series of tests was done in a small arena test format using two different charge sizes at two different scaled distances yielding four sets of data. All arena tests used four sensors with zero, five, ten, or 20 layers of mesh directly in front of the sensors. The second series of tests used a high explosive shock tunnel to replicate the waveform of a large explosive charge in open air at a prescribed scaled distance. Results from these test series can be found in the first two instalments of this series of papers. In May 2008, field tests were performed which applied the aluminium mesh to the undercarriage of a Humvee. These tests served as a proof of concept for application of the mesh in the field. One Humvee was outfitted with mesh while another Humvee acted as the control. Results are discussed. While the aluminium mesh is not ready for deployment in the experimental application method, field testing shows promise in the ability to mitigate IED explosion effects.
Firepower and protection, Blast mitigation, AUTODYN, IED, aluminium mesh
Lachlan Saunders, John Wang, Doug Slater, and John Van den Berg
Energy-absorbing seats have become an important component of aircraft design, providing additional safety for occupants during crash impacts. Although the design of seat systems has not traditionally considered the cushion as an energy absorption device, some new aircraft incorporate cushions as an energy-absorption mechanism, using Visco-elastic Polyurethane (VEPU) foams. The literature indicates that VEPU cushions could potentially result in a significant reduction in impact force to the seat occupant, when compared to more conventional cushions. Vertical impact tests have been conducted on a drop test machine to determine the impact profile of cushions and their potential to reduce force transmitted to a seat occupant during a 2.0–8.2 m/s crash. Traditional basic seat foams and commercially available VEPU foams were used. The VEPU foams significantly reduced the impact loading as expected. The optimum density and stiffness of VEPU cushions depended on the level of maximum impact loading. While more work is required, a properly selected VEPU cushion of the same dimensions as current cushions used in existing aircraft seating is likely to provide significant crashworthiness improvement and also reduce occupant fatigue.
Firepower and protection, blast wave, blast mitigation, injury mitigation, aircraft seating
Elijah D.S. Courtney, Amy C. Courtney, and Michael W. Courtney
Face shields and goggles used by personnel at risk of exposure to explosions are designed to protect from projectiles. However, exposure to the primary blast wave itself can lead to eye and brain injuries, yet little is reported about the ability of transparent armor materials to attenuate a blast wave. In this study, a 79 mm diameter, oxy-acetylene driven shock tube was used to generate a blast-like wave with a peak pressure of 1173 kPa, and the pressure wave transmitted through six transparent armor materials was measured. With the exception of window glass (which shattered), the peak pressure was reduced by more than 20 dB by a 6.35 mm thickness of each material: cast acrylic, –22.63 dB; polycarbonate, –23.13 dB; tempered glass, –29.98 dB; laminated glass, –30.14; and aluminum oxynitride (ALON), –30.99 dB. The results show that different transparent armor materials have different abilities to attenuate a blast wave. Measurements like those in this study would be a useful part of design processes. Though ALON, a transparent ceramic, attenuated the blast wave the most, its current high cost may make tempered glass or laminated glass a better value for many applications, since they performed similarly.
Firepower and protection, Blast mitigation, injury mitigation, transparent armour, transparent armor, blast wave
Neville A. Stanton, Laura A. Rafferty, and Alison Blane
The aim of this paper is to review the extent to which Human Factors methods are able to analyse complex accidents that involve the interaction of multiple systems. The case of the Black Hawk Friendly Fire Shoot Down is taken as it exemplified a System of Systems incident, comprising Black Hawk helicopters, the F-15 jets, the AWACS and the TAOR. The emergent behaviour from the interaction of multiple systems is difficult to anticipate and can have disastrous consequences. The four Human Factors methods applied to the examination of Black Hawk Friendly Fire Shoot Down were AcciMaps, Human Factors Analysis Classification System (HFACS), Systems Theory Accident Model and Process (STAMP) and Event Analysis of Systemic Teamwork (EAST). The analysis shows that the four methods are judged to perform differently across eleven evaluation criteria. In conclusion, the EAST method appears to perform best of the four methods. Future research should seek to establish which of the System of Systems methods could be used for both retrospective analysis (i.e., after an accident has occurred) as well as prospective analysis (i.e., to predict the resilience of systems to accidents).
Human factors, Black Hawk, friendly fire, aircraft seating, AcciMaps, Human Factors Analysis Classification System (HFACS), Systems Theory Accident Model and Process (STAMP), Event Analysis of Systemic Teamwork (EAST)
Paul M. Salmon, Michael G. Lenné, Eve Mitsopoulos-Rubens, Thomas Triggs and Phil Wallace
Technology remains the key driver for training within military systems. As rapid advances in capability continue, the range of technologies available to training system designers is likely to increase significantly; however, there is no universally accepted, theoretically underpinned guidance for selecting, designing, and implementing new training technologies; and the process of linking technologies to training requirements remains ambiguous. Based on a review of the training and human factors literature, a generic model of training technology selection, design, and implementation is presented. The model provides training system designers with guidance on the selection, design, and implementation of new technologies for future training requirements. Each component of the model is discussed with reference to the training system design and evaluation literature. In closing, a series of pertinent future lines of inquiry are discussed.
Human factors, Training Needs Analysis, TNA, technology-based training, military training systems, training
Marcus Thompson
Sean S. Costigan and Jake Perry (eds), Cyberspaces and Global Affairs , Ashgate Publishing Limited, Farnham, 2012 (ISBN 978-1-4094-2754-4).
book review, cybersecurity
