The Use of Finite Element Method in Computing the Dynamic Pressure inside a Fuel Tank and Simulation of Fuel System Pipe Cut During Vehicle Crash to Predict Fuel Leakage

The dynamic behavior of the fuel inside a fuel tank and the fuel pressure caused by the acceleration of the vehicle during a rear crash will determine whether a damage of vehicle fuel system resulting in fuel leakage will occur. The dynamic behavior of the liquid and the gas in the fuel tank depends on the fuel tank capacity, shape, and the level which the fuel tank is filled. The mode and severity of the crash will also affect the pressure distribution inside the tank.

In order to predict fuel system leakage in early stage of vehicle design before any test vehicles are made, it is necessary for the crash analyst to have a tool that can predict this phenomena. The analyst should have the capabilities to compute not only the fuel tank pressure, but also possible fuel system pipe cut during the crash. Using recently developed finite element method for fluid-solid interaction treatment, it looks promissing for the analyst to predict dynamic fuel pressures and potential fuel leakage in the fuel system. Also using material model for rubber, prediction of fuel pipe cuts can be shown. This article describes the utilization of the new capabilities of RADIOSS, a non-linear Finite Element (FE) crash code, to a full vehicle crash model and the predictions of potential fuel system problems. The predictions helped steer the design of a new family of Ford vehicles to meet or exceed the federal and corporate requirements for fuel system integrity.