Approaches to rotor fragment protection

Key airworthiness design criteria considerations for fragment protection as found in various FAA requirements in FAR Parts 25 and 33, and in interpretive 8110 orders are reviewed. The impact of providing aircraft armor in lieu of engine armor for typical three- and four-engine wide bodied transports for protection within the length of the engine case as well as from fragments exiting ahead of the enlet engine inlet flange is assessed. For protection within the length of the engine case, armor weight penalties, plus fuel burned and dollar cost of carrying the armor protection are defined. Immediately ahead of the inlet flange, direct tangential impacts are predominant, but further forward, rebound impacts predominate. Armor thickness requirements and fuel cost impact of protection are given

Body Armor for Law Enforcement Officers: In Brief

[Excerpt] Firearms are one of the leading causes of deaths for law enforcement officers feloniously killed in the line of duty. According to data published by the Federal Bureau of Investigation (FBI), approximately 92% of the 505 non-federal law enforcement officers feloniously killed in the line of duty between 2005 and 2014 were killed by a firearm. Law enforcement officers who are shot in the torso are more likely to die as a result of their injury if they are not wearing a vest. Since FY1999, Congress has provided funding to state, local, and tribal law enforcement agencies to help them purchase armor vests for their officers through the Matching Grant Program for Law Enforcement Armor Vests (also referred to as the Bulletproof Vest Partnership Initiative, hereinafter “the BPV program”). This report provides an overview of the BPV program. It also provides a discussion of data on law enforcement agencies that require their officers to wear armor vests while on duty, research on why officers may choose to wear armor vests research on the life cycle for armor vests, data on the use of body armor by law enforcement officers who were killed with a firearm, and research on the effectiveness of armor vests. The report concludes with a survey of congressional issues policy makers might consider should they take up legislation to reauthorize the BPV program

Ceramic composite protection for turbine disc bursts

Ceramic composite turbine disc protection panels for the A300B were developed using armor technology. Analytical predictions for modifying the ballistic projectile armor system were verified by a test program conducted to qualify the rotor containment system. With only a slight change in the areal density of the armor system a more than two-fold increase in kinetic energy protection level was achieved. Thickness of the fiberglass reinforced plastic backing material was increased to achieve an optimum ratio of ceramic thickness to backing thickness for the different ballistic defeat condition

Improved method for producing metal-reinforced ceramics

Vacuum impregnation process produces metal-reinforced ceramics with only 3 percent void space volumes. Method may be used to produce metal-reinforced ceramics for high temperature or structural applications such as furnace supports and armor

X-Ray Tomography To Measure Size Of Fragments From Penetration Of High-Velocity Tungsten Rods

Behind-armor debris that results from tungsten rods penetrating armor steel at 2 km/s was studied by analysis of recovered fragments. Fragment recovery was by means of particle board. Individual fragments were analyzed by x-ray tomography, which provides information for fragment identification, mass, shape, and penetration down to masses of a few milligrams. The experiments were complemented by AUTODYN and EPIC calculations. Fragments were steel or tungsten generated from the channel or from the breakout through the target rear surface. Channel fragment motions were well described by Tate theory. Breakout fragments had velocities from the projectile remnant to the channel velocity, apparently depending on where in the projectile a fragment originated. The fragment size distribution was extremely broad and did not correlate well with simple uniform-fragment-size models.Mechanical Engineerin

Baseline UT measurements for armor inspection

Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch∕catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through‐transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces

Justification of the suitability of the steel-aluminum bimetal by the calculating criteria of the bulletproof armor protection

У статті порівнюються розрахункові критерії бронестійкости захисних матеріалів, запропоновані різними авторами. Для двошарового біметалу, отриманого зварюванням вибухом, оптимальним визнаний розрахунковий критерій Стігліца. Розрахункове значення критерію Стігліца для біметалу сталь 65Г+алюміній АД0 з рівними товщинами шарів більш ніж в 2 рази перевищує наведені в літературі значення цього критерію для броньової сталі, але, як і для броньованої сталі, на порядок менше значення цього критерію для ефективної противопульної кераміки (гарячепресованого карбіду бору). Даний біметал цілком прийнятний за розрахунковим критерієм противопульної бронестійкости, а з економічних міркувань може успішно конкурувати як з броньовою сталлю, так і з удароміцними броньовими керамічними матеріалами.Purpose. On the basis of well-known calculating criteria of armor protection to compare the common armor protection bulletproof materials (steel armor, armor ceramics) with the bimetal made by explosion welding as a material for a two-layer armor. Design/methodology/approach. Calculating criteria of armor resistance of materials are depending on which includes the density of the material, its micro-hardness and other properties. Density and other properties of the bimetal is determined using well-known formulas. Microhardness of the bimetal's surface is measured. Stiglitz criterion is calculated using these data. Findings. Calculated value of the Stiglitz criterion for bimetal steel 65Г + aluminum AД0 with equal layer thicknesses is more than twice of the value of this criterion (cited in the literature) for armored steel, but as steel armor, in ten times less than the value of this criterion for effective bulletproof ceramics (hot-pressed boron carbide). Originality/value. Bimetal steel 65Г + aluminum AД0 made by explosion welding is quite acceptable from the point of view of calculating criteria of bulletproof armor protection, and from economic reasons can successfully compete with both armor steel and impact-resistant armor ceramic materials.В статье сопоставлены расчетные критерии бронестойкости защитных материалов, предложенные различными авторами. Для двухслойного биметалла, полученного сваркой взрывом, оптимальным признан расчетный критерий Стиглица. Расчетное значение критерия Стиглица для биметалла сталь 65Г+алюминий АД0 с равными толщинами слоев более чем в 2 раза превышает приведенные в литературе значения этого критерия для броневой стали, но, как и для броневой стали, на порядок меньше значения этого критерия для эффективной противопульной керамики (горячепрессованного карбида бора). Данный биметалл вполне приемлем по расчетному критерию противопульной бронестойкости, а по экономическим соображениям может успешно конкурировать как с броневой сталью, так и с ударопрочными броневыми керамическими материалами

Armor

I decided to go as a knight to John Diefendorf’s party. I cut up a piece of cardboard and spray-painted it silver for the shield. I made a lance out of cardboard paper towel rolls. “Very authentic,” said my wife, Betsy. She surveyed the kitchen. “You really did a number in here.” I had spread sheets of newspaper on the floor by the pantry, and various strips of cardboard were scattered on or around the newspaper

Numerical Simulation Of Impact Effects On Multilayer Fabrics

High strength fabrics provide lightweight impact protection and are employed in a wide range of applications. Examples include body armor for law enforcement and military personnel and orbital debris shielding for the International Space Station. Numerical simulation of impact effects on fabric protection systems is difficult., due to the complex woven structure of the fabric layers and the typical application of fabrics in a multilayer configuration. Recent research has applied a new particle-element method to the simulation of impact effects on multilayer fabrics, applicable over a wide range of impact velocities, for use in body armor and orbital debris shielding design applications.Mechanical Engineerin