A review of cervical fractures and fracture-dislocations without head impacts sustained by restrained occupants

Crash injury reduction via lap-shoulder belt use has been well documented. Like any other interior car component, lap-shoulder belts may be related to injury in certain crashes. Relatively unknown is the fact that cervical fractures or fracture-dislocations to restrained front seat occupants occur where no head contact was evidenced by both medical records and car inspection. A review of the available literature on car crash injuries revealed more than 100 such cases. A review of the National Accident Severity Study (NASS) 80-88 file was also conducted, revealing more examples. Case capsule descriptions from the authors' files are also detailed along with examples of such injuries in infants and children in child restraints. However, cervical fractures or fracture dislocations are rare, as evidenced by the relatively few cases identified in the literature, in the author's files, and by an analysis of NASS 80-90 data that revealed a cervical spine injury frequency of only .4% at the AIS-3 level (Hueike, Morris, and Mackay 1992).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30429/1/0000050.pd

Investigation of flash-butt welded steel bars seam microstructure

Suvirinimas viena iš svarbiausių metalinių konstrukcijų neišardomų sujungimu technologijų. Elektrinis kontaktinis aplydomasis suvirinimas – vienas iš plačiai taikomų automatizuotų suvirinimo būdų. Procesas yra našus, patikimas, nereikalaujantis aptarnaujančio personalo ypatingos kvalifika-cijos. Virinant aplydomuoju būdu, ruošinių galai įkaitinami iki lydymosi temperatūros, paskui sus-legiami. Tarp spaustuvuose įtvirtintų ruošinių paliekamas tarpas, o įjungus įtampą, jie tolygiai suar-tinami. Iš pradžių susiglaudžia atskiri nedideli ruošinių ploteliai, per kuriuos praleidžiama didelio tankio elektros srovė. Kai visas sandūrinis paviršius tolygiai apsilydo, išjungiama srovė ir veikiant nedidelei jėgai, ruošiniai susodinamiOne of most important all-in-one joints of metallic construction is welding. Flash butt welding - process widely used as automotive welding process. The beam welded steam microstructure view shows that in the center of a steam the bright area is visible, which smoothly moves into the darker structures containing metal. According on the microstructure and microhardness research results suggest that the bright zone has a ferritic structure latter smoothly getting into recrystallized pearlite and then into the base of rolled metal structure. Ruptured samples (after bending tests) microstructu-re show that the strength of seam center is low - crack spread by white zoneVytauto Didžiojo universitetasŽemės ūkio akademij

Frontal corner impacts - Crash tests and real-world experience

In North America, frontal crash tests in both the regulatory environment and consumer-based safety rating schemes have historically been based on full-width and moderate-overlap (40%) vehicle to barrier impacts. The combination of improved seat-belt technologies, notably belt tensioning and load limiting systems, together with advanced airbags, has proven very effective in providing occupant protection in these crash modes. Recently, however, concern has been raised over the contribution of narrower frontal impacts, involving primarily the vehicle corners, to the incidence of fatality and serious injury as a result of the potential for increased occupant compartment intrusion and performance limitations of current restraint systems. Drawing on data documented in the National Automotive Sampling System (NASS)/ Crashworthiness Data System (CDS) for calendar years 1999 to 2012, the present study examines the characteristics of existing and proposed corner crash test configurations, and the nature of real-world collisions that approximate the test environments. In this analysis, particular emphasis is placed on crash pulse information extracted from vehicle-based event data recorders (EDR's)

Assessing the field relevance of testing protocols and injury risk functions employed in new car assessment programs

Over the past two decades the popularity of consumer crash test programs, commonly referred to as New Car Assessment Programs (NCAP), has grown across the world. They are popular among government regulators as they afford a means of promoting safety innovations and levels of vehicle performance beyond those dictated by national standards. They also fulfill the demand for information regarding the safety ranking of vehicles among consumers contemplating the purchase of a new vehicle. There is no question that consumer crash test programs greatly influence vehicle design changes as well as accelerate the fitment of new safety features. The extent to which these changes can be expected to reduce serious and potentially fatal injuries will be influenced by how well the testing protocols and associated rating schemes correctly reflect the nature of the residual safety problem they seek to address. Drawing on data contained primarily in the US National Automotive Sampling System (NASS), the field relevance of current and proposed testing and rating protocols addressing frontal crash test protection is examined. Emphasis is placed on examining how accurately injury rates computed from the dummy responses measured in consumer crash tests correspond to actual injury rates observed in the field. Additional data from Canadian field investigations and US databases such as the National Motor Vehicle Crash Causation Survey (NMVCCS) are examined to see how well frontal airbag firing times, crush pulse durations and other determinants of injury are replicated in consumer testing protocols. This portion of the analysis draws on data obtained from Event Data Recorders (EDR) in both field collisions and staged tests of the same vehicle model. Vehicle rankings and overall frontal crash test ratings were found to be particularly sensitive to the choice of injury risk functions employed in the test. This was particularly true in the case of injury risk functions used to assess neck injury potential. Neck injury risk derived from Nij was found to show the least agreement with the field. Agreement between field chest injury rates and those derived from crash tests was improved considerably when chest injury risk functions for "older" occupants were employed. The paper concludes with a discussion of how different current testing protocols could be improved to enhance their field relevance