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When a vehicle with a partially filled fuel tank undergoes sudden acceleration, braking, turning or pitching motion, fuel sloshing is experienced. It is important to establish a CAE methodology to accurately predict slosh phenomenon. Fuel slosh can lead to many failure modes such as noise, erroneous fuel indication, irregular fuel supply at low fuel level and durability issues caused by high impact forces on tank surface and internal parts. This paper summarizes activities carried out by the fuel system team at Ford Motor Company to develop and validate such CAE methodology. In particular two methods are discussed here. The first method is Volume Of Fluid (VOF) based incompressible multiphase Eulerian transient CAE method. The CFD solvers used here are Star CD and Star CCM+. The second method incorporates Fluid-Structure interaction (FSI) using Arbitrary Lagrangian-Eulerian (ALE) formulation.

With years of experience in applying CAE (Computer-Aided Engineering) tools in different automotive plastics component design analyses, authors try to define the accuracy of CAE simulations through three carefully selected case studies: natural frequency prediction, vibration stress calculation, and fatigue analysis. The first case study demonstrates that CAE is able to achieve great accuracy in predicting structural global properties such as natural frequency. The second case shows that CAE results do not correlate so well for the predictions of local properties such as vibration induced stress or strain response, while the third one indicates that CAE predictions on A to B comparison is always accurate even in the case of fatigue life prediction, that is known as a difficult task. Therefore, the CAE global property predictions should weigh heavier in plastic component design evaluation than on the local ones.

Plastics injection molds are typically subjected to a combination of loadings such as injection pressure, temperature changes, clamping force, and potential interference at seal-off surfaces during manufacturing process. The loadings on the molds are as cyclic as the injection molding cycles. As a result, the molds could fail either in material overstraining or fatigue. In this paper, several failure cases will be presented, along with the FEA stress and fatigue analysis results, to demonstrate the effect of the above mentioned loadings on the mold structural integrity. This paper will also show how the FEA stress and fatigue analyses were effectively employed to determine the mold failure root cause and assist the design modification in a usually constrained time frame.

Leakage and permeability through fuel systems is an ongoing problem that both environmentalists and automakers face, but with the application of multi-layer plastic material technology and new manufacturing processes of internalizing components, partial zero emissions vehicles (PZEV) can be achieved. The legislative requirements that must be met for the future fuel systems regarding their permeation and leakage performance are discussed. Recent efforts on how the automotive industry is responding to meet those challenges are also presented.

In this paper, a CAE (Computer-Aided Engineering) methodology to simulate the vibration test and predict fatigue life of head lamp bulb shield is presented. A modal analysis is performed first to determine the critical elements from the strain energy density distribution patterns. A random vibration frequency response analysis is then performed to monitor the stress response power spectral densities (PSDs) for critical elements due to the g-load input PSDs, measured at the mounting point in all three directions. Fatigue life can be estimated based on the stress response PSDs and material S-N curve by using Dirlik's method. The fundamentals for frequency domain fatigue analysis are reviewed and a case study with test correlation is then presented.