Crashworthiness

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. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. Crashworthiness may be assessed either prospectively, using computer models (e.g., LS-DYNA, 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 assessed retrospectively by analyzing injury risk in real-world crashes, often using regression or other statistical techniques to control for the myriad of confounders that are present in crashes.

Contents

History

Aviation

The history of aviation crashworthiness can likely trace its beginning in the studies by John Stapp to investigate the limits of human tolerance in the 1940s and 1950s. In the 1950s and 1960s, the US Army beginning serious accident analysis into crashworthiness as a result of fixed-wing and rotary-wing accidents. As the Army's doctrine changed, helicopters became the primary mode of transportation in Vietnam. Pilots were receiving spinal injuries in otherwise survivable crashes due to decelerative forces on the spine and fires. Work began to develop energy absorbing seats to reduce the chance of spinal injuries.[1] during training and combat in Vietnam. Heavy research was conducted into human tolerance, energy attenuation and structural designs that would protect the occupants of military helicopters.[2][3] The primary reason is that ejection or exiting a helicopter is impractical given the rotor system and typical altitude at which Army helicopters fly. In the late 1960s the Army published the Aircraft Crash Survival Design Guide.[4] The guide was revised several times and became a muli-volume set divided by aircraft systems. The intent of this guide is to assist engineers in understanding the design considerations important to crash-resistant military aircraft. Consequently, the Army establish a military standard (MIL-STD-1290A) for light fixed and rotary-wing aircraft.[5] The standard establishes minimum requrements for crash safety for human occupants based on the need to maintain a livable volume or space and the reduction of decelerative loads upon the occupant.[6]

Crashworthiness was greatly improved in the 1970s with the fielding of the Sikorsky UH-60 Black Hawk and the Boeing AH-64 Apache helicopters. Primary crash injuries were reduced, but secondary injuries within the cockpit continued to occur. This led to the consideration of additional protective devices such as airbags. Airbags were considered a viable solution to reducing the incidents of head strikes in the cockpit, and were incorporated in Army helicopters.

Current stakeholders

The Federal Aviation Administration has been the proponent for general aviation safety in the United States. It has developed its own authoritative safety requirements in the Code of Federal Regulations.[7]

At the time NASA has conducted similar work study the effects of space launch for human space flight. They also conducted crash testing beginningin the 1950s.[8]

The US Department of Transportation has developed standards for private and commercial forms of transportation.

See also

References

External links


Wikimedia Foundation. 2010.

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Look at other dictionaries:

  • crashworthiness — noun see crashworthy …   New Collegiate Dictionary

  • crashworthiness — crashworthy, adj. /krash werr dhee nis/, n. the ability of a car or other vehicle to withstand a collision or crash with minimal bodily injury to its occupants. [1945 50; CRASH1 + WORTHY + NESS] * * * …   Universalium

  • crashworthiness — noun The state or quality of being crashworthy …   Wiktionary

  • crashworthiness — n. resistant to the effects of a car collision, extent to which a car or other vehicle will protect its occupants from the outcomes of an accident or collision …   English contemporary dictionary

  • crashworthiness — The ability of an aircraft structure and components to withstand damage caused in a crash without severely injuring occupants or preventing their escape from a wreckage …   Aviation dictionary

  • crashworthiness — noun the degree to which a vehicle will protect its occupants from the effects of an accident. Derivatives crashworthy adjective …   English new terms dictionary

  • crashworthiness — crash•wor•thi•ness [[t]ˈkræʃˌwɜr ði nɪs[/t]] n. cvb aum the ability of a car or other vehicle to withstand a crash with minimal bodily injury to its occupants • Etymology: 1945–50 crash′wor thy, adj …   From formal English to slang

  • crashworthiness — Doctrine which imposes liability upon a manufacturer in a vehicular collision case for design defects which do not cause the initial accident but which cause additional or more severe injuries when the driver or passenger subsequently impacts… …   Black's law dictionary

  • crashworthiness — Doctrine which imposes liability upon a manufacturer in a vehicular collision case for design defects which do not cause the initial accident but which cause additional or more severe injuries when the driver or passenger subsequently impacts… …   Black's law dictionary

  • crashworthiness — noun see crashworthy …   Useful english dictionary

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