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Buff Strength
Buff strength is a design term used in the certification of rail rolling stock. It refers to the required resistance to deformation or permanent damage due to loads applied at the car's ends, such as in a collision. Particular emphasis on buff strength is placed in the United States, with buff strength requirements there being higher than in Europe. United States Buff strength requirements grew out of best-practice design standards during the latter part of the nineteenth century. By the twentieth century, a design limit of was required by federal approval agencies. This was upped to for certain categories in 1945. Federal requirements for buff strength were set in 1999 at for all passenger-carrying units, unless reduced by waivers or special order. The Federal Static and Strength Regulation (49 Code of Federal Regulations § 238.203) requires that a passenger rail car be able to support a longitudinal static compressive load of without permanent deformation. There are other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crumple Zone
Crumple zones, crush zones or crash zones are a structural safety feature used in vehicles, mainly in automobiles, to increase the time over which a change in velocity (and consequently momentum) occurs from the impact during a collision by a controlled deformation; in recent years, it is also incorporated into trains and railcars. Crumple zones are designed to increase the time over which the total force from the change in momentum is applied to an occupant, as the average force applied to the occupants is inversely related to the time over which it is applied. The physics involved can be expressed by the equation: F_\text\Delta t = m\Delta v where F is the force, t is the time, m is the mass, and v is the velocity of the body. In SI units, force is measured in newtons, time in seconds, mass in kilograms, velocity in metres per second, and the resulting impulse is measured in newton seconds (N⋅s). Typically, crumple zones are located in the front part of the vehicl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressive Strength
In mechanics, compressive strength (or compression strength) is the capacity of a material or Structural system, structure to withstand Structural load, loads tending to reduce size (Compression (physics), compression). It is opposed to ''tensile strength'' which withstands loads tending to elongate, resisting Tension (physics), tension (being pulled apart). In the study of strength of materials, compressive strength, tensile strength, and shear strength can be analyzed independently. Some materials fracture at their compressive strength limit; others Plasticity (physics), deform irreversibly, so a given amount of Deformation (engineering), deformation may be considered as the limit for compressive load. Compressive strength is a key value for Structural engineering, design of structures. Compressive strength is often measured on a universal testing machine. Measurements of compressive strength are affected by the specific test method and conditions of measurement. Compressive s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Container Compression Test
The container compression test measures the compressive strength of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force. It is commonly used to evaluate shipping containers made of corrugated fiberboard as well as wooden boxes and crates. Industrial and consumer packages other than boxes can also be subjected to compression testing: drum, pail, bottle, tub etc. Package components are also evaluated for compression resistance. It is usually a laboratory test involving a special machine, a compression tester, to apply controlled compression on a test specimen. A universal testing machine is sometimes configured to perform a package compression test. Compression testing can also involve a superimposed ''dead load'' to a test package. Test procedures A common method of conducting the test, as described in several published standard test methods, is to compress a box at a constant rate of between two rigid platens. The platens ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Different criteria are used to figure out how safe a structure is in a crash, depending on the type of impact and the vehicle involved. Crashworthiness may be assessed either prospectively, using computer models (e.g., RADIOSS, LS-DYNA, PAM-CRASH, MSC Dytran, MADYMO) or experiments, or retrospectively, by analyzing crash outcomes. Several criteria are used to assess crashworthiness prospectively, including the deformation patterns of the vehicle structure, the acceleration experienced by the vehicle during an impact, and the probability of injury predicted by human body models. Injury probability is defined using criteria, which are mechanical parameters (e.g., force, acceleration, or deformation) that correlate with injury risk. A common injury criterion is the head impact criterion (HIC). Crashworthiness is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deformation (engineering)
In engineering, deformation (the change in size or shape of an object) may be ''elastic'' or ''plastic''. If the deformation is negligible, the object is said to be ''rigid''. Main concepts Occurrence of deformation in engineering applications is based on the following background concepts: * ''Displacements'' are any change in position of a point on the object, including whole-body translations and rotations ( rigid transformations). * ''Deformation'' are changes in the relative position between internals points on the object, excluding rigid transformations, causing the body to change shape or size. * ''Strain'' is the ''relative'' ''internal'' deformation, the dimensionless change in shape of an infinitesimal cube of material relative to a reference configuration. Mechanical strains are caused by mechanical stress, ''see stress-strain curve''. The relationship between stress and strain is generally linear and reversible up until the yield point and the deformation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headstock (rolling Stock)
A headstock of a Railroad car, rail vehicle is a transverse structural member located at the extreme end of the vehicle's underframe. The headstock supports the railway coupling, coupling at that end of the vehicle, and may also support Buffer (rail transport), buffers, in which case it may also be known as a buffer beam. The headstocks form part of the underframe of a locomotive or a railroad car. The headstocks of locomotives, railcars and Control car (rail), cabcars also support Locomotive headlamp, headlamps and the Hose (tubing), hoses for Railway air brake, air brakes, vacuum brakes as well as the Electrical cable, cables for Push–pull train, train control and head end power. Length over headstocks A commonly used measurement relating to a rail vehicle is its length over headstocks, which is the length of the vehicle excluding its Railway coupling, couplings or Buffer (rail transport), buffers (if any). Alternative expressions for length over headstocks are length ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railworthiness
Railworthiness South African Qualifications Authority (SAQA). (visited on April 03, 2011) is the property or ability of a , , , or any kind of |
Rail Transport
Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of land transport, next to road transport. It is used for about 8% of passenger and rail freight transport, freight transport globally, thanks to its Energy efficiency in transport, energy efficiency and potentially high-speed rail, high speed.Rolling stock on rails generally encounters lower friction, frictional resistance than rubber-tyred road vehicles, allowing rail cars to be coupled into longer trains. Power is usually provided by Diesel locomotive, diesel or Electric locomotive, electric locomotives. While railway transport is capital intensity, capital-intensive and less flexible than road transport, it can carry heavy loads of passengers and cargo with greater energy efficiency and safety. Precursors of railways driven by human or an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
