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In the design of an automobile, an important consideration is to minimize the amount of “boom” noise that the vehicle occupant could experience. Vehicles equipped with four cylinder engines can experience powertrain boom noise in the 40 to 200 Hz frequency range. Boom noise can also be generated by road input, and it is just as annoying. In this paper, a CAE methodology for predicting boom noise is demonstrated for a vehicle in the early design stage in which only 3-D CAD geometry exists. From the CAD geometry, a detailed finite element (FE) model is constructed. This FE model is then coupled with an acoustic model of the interior cavity. The coupled structural-acoustic model is used to predict acoustic response due to powertrain inputs. As a part of the detailed design process, various design modifications were considered and implemented in the vehicle system model. Many of these modifications proved successful at reducing the boom levels in the vehicle.

In order to obtain an automatically designed shape of engine mount, an optimum shape design process of engine mounting rubber is introduced. After the primary stiffness values of an engine mount system are determined, the secondary stiffness values and the shapes are designed. By using nonlinear spring analysis, the design of the secondary stiffness and the gap size of engine mount can be carried out. In this work, the finite element program including the optimization code is developed and used. The optimum shape design process of engine mounting rubber using a parametric approach is suggested. The optimization code is used with the commercial nonlinear finite element program to determine the shape to satisfy the stiffness requirements of engine mounts. An engine mount system used in a passenger car is chosen for an application model. Three engine mounts are designed by the procedure mentioned above.

The aim of this study is to prepare polypropylene (PP) / nickel coated carbon fiber (NiCF) or stainless steel (SUS) fiber composites possessing electromagnetic interference (EMI) shielding effectiveness (SE). A series of conductive composites were prepared by the melt blending method. The EMI SE of conductive composites is 45 dB over a wide frequency range up to 100 MHz, which is higher than that of PP/talc composite used automotive interior parts, viz. 0 dB.

This paper describes a study that was conducted to determine sensitivity of several design factors for reducing injury values of occupants upon side impact using Taguchi method. The full mid-sized vehicle finite element model is used for the analysis under two different side impact standards~SINCAP and ECE-R 95. The design factors that may have major effect on side impacts were selected and L8 orthogonal array was set up for analysis. Analysis results show that strengthening the passenger compartment improves occupant protection, especially adding a pusher foam is significantly lowering the injury values in SINCAP. No single factor has major effects on rib deflection which is considered as critical occupant injury criterion in ECE- R 95. Taguchi method was found to be a useful tool, although its usage may be limited in crash analysis, for predicting the effect of various design factors on structure.