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Frangible
A material is said to be frangible if through deformation it tends to break up into fragments, rather than deforming elastically and retaining its cohesion as a single object. Common crackers are examples of frangible materials, while fresh bread, which deforms plastically, is ''not'' frangible. A structure is frangible if it breaks, distorts, or yields on impact so as to present a minimum hazard. A frangible structure is usually designed to be frangible and to be of minimum mass. Light poles A frangible light pole base is designed to break away when a vehicle strikes it. This lessens the risk of injury to occupants of the vehicle. Frangible supports are also used for airport approach structures. Bullets A frangible bullet is one that is designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the danger behind the intended target. Examples are the Glaser Safety Slug and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frangible Bullet Stress Test
A material is said to be frangible if through deformation it tends to break up into fragments, rather than deforming elastically and retaining its cohesion as a single object. Common crackers are examples of frangible materials, while fresh bread, which deforms plastically, is ''not'' frangible. A structure is frangible if it breaks, distorts, or yields on impact so as to present a minimum hazard. A frangible structure is usually designed to be frangible and to be of minimum mass. Light poles A frangible light pole base is designed to break away when a vehicle strikes it. This lessens the risk of injury to occupants of the vehicle. Frangible supports are also used for airport approach structures. Bullets A frangible bullet is one that is designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the danger behind the intended target. Examples are the Glaser Safety Slug and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frangible Bullet
Frangible bullets are intended to disintegrate into tiny particles upon target impact to minimize their penetration of other objects. Small particles are slowed more rapidly by air resistance, and are less likely to cause injury or damage to persons and objects distant from the point of bullet impact. Most frangible bullets are subject to brittle failure upon striking a hard target. This mechanism has been used to minimize the tendency of malleable lead and copper bullets to ricochet from hard targets as large, cohesive particles. Brittle failure may occur at subsonic velocity. Attempting to crimp a brittle frangible bullet into the cartridge case may break the bullet. Brittle frangible bullets may break during the self-loading cycle of semi-automatic firearms; and those fired from revolvers often break as the bullet encounters the barrel forcing cone after leaving the cylinder. Manufacturing Powder metallurgy techniques fabricate bullets from mixtures of powdered metals (typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breaching Round
A breaching round or slug-shot is a shotgun shell specially made for door breaching. It is typically fired at a range of 6 inches (15 cm) or less, aimed at the hinges or the area between the doorknob and lock and doorjamb, and is designed to destroy the object it hits and then disperse into a relatively harmless powder. Design and construction Breaching rounds are designed to destroy door deadbolts, locks, and hinges without risking lives by ricocheting or by flying on at lethal speed through the door, as traditional buckshot can. These frangible rounds are made of a dense sintered material, often metal powder in a binder such as wax, which can destroy a lock or hinge and then immediately disperse. They are used by military and SWAT teams to quickly force entry into a locked room. Amongst police, these rounds are nicknamed " master keys", and their use is known as "Avon calling", alluding to the Avon brand of cosmetics which was sold door-to-door. Ideally, breaching rounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaser Safety Slug
Glaser Safety Slug is a frangible bullet made by Cor-Bon/Glaser, a subsidiary of Dakota Ammo, an American ammunition company based in Sturgis, South Dakota. The Glaser Safety Slug was developed by Jack Canon in 1975, the same year the company was founded by Armin Glaser. History The original round was a hand-made hollow point bullet filled with No. 12 birdshot () with a flat polymer cap. To improve ballistic performance, a polymer-tipped round ball was introduced in 1987, and the current compressed core form was first sold in 1988. The formulation of the polymer was also changed in 1994 to improve fragmentation reliability. Performance The company produces bullets in calibers from .25 to .45 for pistols and from .223 to .30-06 for rifles. Each caliber comes in two forms, "blue" and "silver", the latter having greater penetrating power due to the use of no. 6 birdshot rather than no. 12. The projectile in the cartridge is of a lighter weight than more conventional types of car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricochet
A ricochet ( ; ) is a rebound, bounce, or skip off a surface, particularly in the case of a projectile. Most ricochets are caused by accident and while the force of the deflection decelerates the projectile, it can still be energetic and almost as dangerous as before the deflection. The possibility of ricochet is one of the reasons for the common firearms safety rule "Never shoot at a flat, hard surface." Ricochets can occur with ''any'' caliber, but short or round ricocheting bullets may not produce the audible whine caused by tumbling irregular shapes. Ricochets are a hazard of shooting because, for as long as they retain sufficient velocity, ricocheting bullets or bullet fragments may cause collateral damage to animals, objects, or even the person who fired the shot. Variables Ricochets occur when a bullet or bullet fragment is deflected by an object rather than penetrating and becoming embedded in that object. Ricochet behavior may vary with bullet shape, bullet material, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friability
Friability ( ), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing. The opposite of friable is indurate. Substances that are designated hazardous, such as asbestos or crystalline silica, are often said to be friable if small particles are easily dislodged and become airborne, and hence respirable (able to enter human lungs), thereby posing a health hazard. Tougher substances, such as concrete, may also be mechanically ground down and reduced to finely divided mineral dust. However, such substances are not generally considered friable because of the degree of difficulty involved in breaking the substance's chemical bonds through mechanical means. Some substances, such as polyurethane foams, show an increase in friability with exposure to ultraviolet radiation, as in sunlight. Friable is sometimes used metaphorically to describe "brittle" personalities who can be "rubbed" by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Security Tape
Security tape (or security label) is a type of adhesive tape used to help reduce shipping losses due to pilfering and theft. It helps reduce tampering or product adulteration. Often it is a pressure sensitive tape or label with special tamper resistant or tamper evident features. It can be used as a ‘’security seal’’ in addition to a container closure or can be used as a security label. They are sometimes used as or with authentication products and can be an anti-pilferage seal. Security tapes and labels are sometimes used in conjunction with security envelopes. Use Security tapes can be used as packaging tapes on small primary packages such as bottles and cartons or on larger shipping containers such as corrugated boxes. They are also used on unit loads or palletized goods. The strength and adhesive bonding are important. Security labels are usually only used for their security features; backing strength is less important but the bonding characteristics ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instrument Landing System
In aviation, the instrument landing system (ILS) is a precision radio navigation system that provides short-range guidance to aircraft to allow them to approach a runway at night or in bad weather. In its original form, it allows an aircraft to approach until it is over the ground, within a of the runway. At that point the runway should be visible to the pilot; if it is not, they perform a missed approach. Bringing the aircraft this close to the runway dramatically increases the range of weather conditions in which a safe landing can be made. Other versions of the system, or "categories", have further reduced the minimum altitudes, runway visual ranges (RVRs), and transmitter and monitoring configurations designed depending on the normal expected weather patterns and airport safety requirements. ILS uses two directional radio signals, the ''localizer'' (108 to 112 MHz frequency), which provides horizontal guidance, and the ''glideslope'' (329.15 to 335 MHz frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spall
Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball bearing). Spalling and spallation both describe the process of surface failure in which spall is shed. The terms ''spall'', ''spalling'', and ''spallation'' have been adopted by particle physicists; in neutron scattering instruments, neutrons are generated by bombarding a uranium (or other) target with a stream of atoms. The neutrons that are ejected from the target are known as "spall". Mechanical spalling Mechanical spalling occurs at high stress contact points, for example, in a ball bearing. Spalling occurs in preference to brinelling where the maximal shear stress occurs not at the surface, but just below, shearing the spall off. One of the simplest forms of mechanical spalling is plate impact, in which two waves of compression ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrificial Part
A sacrificial part is a part of a machine or product that is intentionally engineered to fail under excess mechanical stress, electrical stress, or other unexpected and dangerous situations. The sacrificial part is engineered to fail first, thus breaking the serial connection and protecting other parts of the system downstream. Examples Examples of sacrificial parts include: * Electrical fuses * Over-pressure burst disks * Mechanical shear pins * Galvanic anodes * Pyrotechnic fastener * Fusible plug * Some leader lines used in angling Angling is a fishing technique that uses a fish hook or "angle" (from Old English ''angol'') attached to a fishing line to tether individual fish in the mouth. The fishing line is usually manipulated via a fishing rod, although rodless techni ... See also * * * Mechanical engineering Safety equipment {{Tech-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tempered Glass
Tempered or toughened glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempering puts the outer surfaces into compression and the interior into tension. Such stresses cause the glass, when broken, to shatter into small granular chunks instead of splintering into jagged shards as ordinary annealed glass does. The granular chunks are less likely to cause injury. Tempered glass is used for its safety and strength in a variety of applications, including passenger vehicle windows, shower doors, aquariums, architectural glass doors and tables, refrigerator trays, mobile phone screen protectors, bulletproof glass components, diving masks, and plates and cookware. Properties Tempered glass is about four times stronger than annealed glass. The greater contraction of the inner layer during manufacturing induces compressive stresses in the surface of the glass balanced by tensile stresses i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deformation (engineering)
In engineering, deformation refers to the change in size or shape of an object. ''Displacements'' are the ''absolute'' change in position of a point on the object. Deflection is the relative change in external displacements on an object. Strain is the ''relative'' internal change in shape of an infinitesimally small cube of material and can be expressed as a non-dimensional change in length or angle of distortion of the cube. Strains are related to the forces acting on the cube, which are known as stress, by a stress-strain curve. The relationship between stress and strain is generally linear and reversible up until the yield point and the deformation is elastic. The linear relationship for a material is known as Young's modulus. Above the yield point, some degree of permanent distortion remains after unloading and is termed plastic deformation. The determination of the stress and strain throughout a solid object is given by the field of strength of materials and for a structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
