The purpose of this analysis has been the evaluation of the crashworthiness of the so called "CNG Fuel Storage Chassis" design. This chassis design integrates compressed natural gas (CNG) fuel cylinders within the modified frame rail structure of a Dodge B-3500 van for the purpose of attaining a vehicle range of about 640 km (400 miles) compared to a range of 240 km (150 miles) for the CNG production version of the Dodge B-3500 van with the same chassis design as the gasoline production model. Thus, the "CNG Fuel Storage Chassis" allows for a total storage of more than 110 liters (30 gallons) of gasoline equivalent fuel. The analytical crashworthiness model of the fuel storage chassis makes use of the DYNA-3D code, which is a finite element program specifically designed to analyse high-speed impact problems exhibiting a high degree of geometric and material non-linearity. The model development and analysis have been performed on a fast personal computer (PC) utilising a 133 MHz Intel Pentium processor. Two different types of CNG tank technologies have been considered in this analysis: a fully wrapped fiberglass on aluminium technology and an all carbon technology. Three impact cases have been analysed in accordance with the appropriate US federal standards: a frontal impact at 48 km/h (30 mph); a lateral impact at 32 km/h (20 mph); and a rear impact at 48 km/hr (30 mph). The DYNA-3D finite element model developed for the "CNG Fuel Storage Chassis" consists of 1676 nodes and 1730 shell elements - one-half of the chassis and body due to symmetry. The results of the analysis indicate that the "CNG Fuel Storage Chassis" displays a sound engineering prototype level design. A few improvements have also been recommended to enhance further the soundness of the design. For the covering abstract see ITRD E116488.
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