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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.

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.

Impacts between passenger vehicles and heavy vehicles are uniquely severe due to the aggressivity of the heavy vehicles; this is a function of the difference in their geometry and mass. Side crashes with heavy vehicles are a particularly severe crash type due to the mismatch in bumper/structure height that often results in underride and extensive intrusion of the passenger compartment. Underride occurs when a portion of one vehicle, usually the smaller vehicle, moves under another, rendering many of the passenger vehicle safety systems ineffective. Heavy vehicles in the US, including single-unit trucks, truck tractors, semi-trailers, and full trailers, are currently not required to have side underride protection devices. The NTSB, among other groups, has recommended that side underride performance standards be developed and that heavy vehicles be equipped with side underride protection systems that meet those standards.

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.