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A typical production transit bus with vertical pillars of small section size, low gauge and low strength steel, exhibits extensive lateral pillar side-sway collapse (matchboxing) in rollover impacts. This matchboxing allows rollover of the bus onto its roof. LS-DYNA simulations demonstrate that roof pillars of high strength steel or inexpensive E-glass fiber reinforced polymer (FRP) pultrusions can prevent matchboxing and arrest the rollover of the bus. However, for the same space envelope, pultruded FRP pillars can be at least 41% lighter than high strength steel square tubes exhibiting the same bending moment capacity.

More than 900,000 long-haul sleeper cabs are projected to be on the road by 2030. About half of heavy truck occupant fatalities occur in rollovers. This paper discusses the current status of rollover protection systems for occupants in sleeper cabs and describes the outcomes from example crashes with sleeper cab occupants. A virtual testing methodology for evaluation of current designs under rollover conditions and restraint tests utilizing dummies and humans also are described. The paper includes discussion of finite element models used and their validation. Examples of results associated with various restraint system configurations are presented. The results show that incorporating effective lateral restraint is important in providing protection to sleeper cab occupants under rollover conditions.

The objective of this study was to demonstrate the ability to reproduce the impact environment occurring in rollover crash tests. There are over 26,000 fatalities and serious injuries annually occurring in rollover accidents in the United States [1]. Many of these are to restrained occupants and their head and spinal injuries have been associated with contact with the roof structure. Finite element models of the Hybrid III dummy and vehicles were used to model the rollover crash tests conducted for Ford. The rollover crash tests involved a production vehicle in a baseline form and one with a roll cage added to it. The impact conditions were incorporated and the results compared with the published test results. The results show that finite element modeling can reproduce the results from rollover crash tests.

Rollover test equipment is of interest in the development of rollover protection system designs. The Controlled Rollover Impact System (CRIS) by Exponent and the Jordan Rollover System (JRS) from the original founder of VIA Systems represent two such systems available. The two systems represent significantly different approaches to the same problem; the CRIS utilizes a structure moving over the ground, while the JRS utilizes a rotating vehicle over a moving ground. Finite Element (FE) modeling of CRIS impacts has been presented previously. In this paper, the ability to model the JRS system is demonstrated. A Finite Element model of the JRS was created and compared with an over-the-ground rollover under the same conditions. An analysis using Finite Element models of a production and roll-caged vehicles and Hybrid III dummies with the CRIS and JRS devices under the same impact conditions then was conducted. The results of the analysis are provided and discussed.

The Federal Motor Vehicle Safety Standard 226 (FMVSS 226) ejection mitigation standard proposes to measure the performance of ejection mitigation countermeasures (like side curtain airbags) in side impacts and rollovers. An ejection impactor, consisting of a head form attached to a shaft, is propelled at the airbag system at different locations, and the ability of the system to prevent complete or partial ejection out of the side window portals is documented. The friction between the head form and airbag can affect the performance of the airbag to retain the impactor, particularly when the impactor strikes at the bottom of the airbag near the windowsill level. In this study, friction tests were conducted to measure the friction coefficients between a head form scalp material and airbag fabric, human hair and airbag fabric, and human skin and airbag fabric.

Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. In this study, the effect of incorporating the fuel storage system within advanced technology tapered frame rails was evaluated using virtual testing under impact conditions. The impact performance was evaluated under a range of horizontal impacts conditions. The performance observed was quantified and then compared with previous testing of baseline diesel tank systems. Fuel storage system impact performance metrics over the range of crash conditions considered were quantified using virtual testing methods. The results obtained from the application of the impact performance evaluation methodology were then described.

The incidence of fire in heavy trucks has been shown to be about ten times higher under crash conditions than occurs in passenger vehicles. Fuel tank protection testing defined in SAE standard J703 was originally issued in 1954 and presently echoes federal regulations codified in 49 CFR 393. These tests do not reflect dynamic impact conditions representative of those that can be expected by heavy trucks on the road today. Advanced virtual testing of current and alternative fuel tank designs and locations under example impact conditions is reported. Virtual testing methods can model vehicle to vehicle and vehicle to fixed object impacts. These results can then be utilized to evaluate and refine fuel tank protection system design approaches.