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There is an increased use of elastomers in the automotive industry for sealing, noise isolation, load dampening, insulation, etc., because of their key properties of elasticity and resilience. Elastomers are used in supercharger application for dampening the torsional fluctuation from the engine, to reduce noise issues. Finite element modeling of elastomers is challenging because of its non-linear behavior in different loading directions. It also undergoes very large elemental deformation (~up to 200%), which results in additional complexities in getting numerical convergence. Finally, it also exhibits viscous and elastic behavior simultaneously (viscoelastic effect) and it undergoes softening with progressive cyclic loading (Mullins effect). The present study deals with the characterization of elastomers for its modeling in commercial finite element software packages and verification of some predicted design parameters with physical testing.

The demand for injection molded reinforced plastic products used in the automotive industry is growing due to the capability of the material for volume production, high strength to weight ratio, and its flexibility of geometry design. On the other hand, the application of fiber filled plastic composites has been challenging and subject of research during past decades due to the inability to accurately predict the mechanical strength and stiffness behavior owing to its anisotropic characteristics. This paper discusses a numerical simulation based technique using multiscale (2 scale Micro-Macro) modeling approach for short fiber reinforced plastic composites. Fiber orientation tensors and knit lines are predicted in microscale analysis using Autodesk Inc.’s Moldflow® software, and structural analysis is performed considering the homogenized structure in macroscale analysis using ANSYS® software tool.

Supercharger gear whine noise has been a NVH concern for many years, especially around idle rpm. The engine masking noise is very low at idle and the supercharger is sensitive to transmitted gear whine noise from the timing gears. The low loads and desire to use spur gears for ease in timing the rotors have caused the need to make very accurate profiles for minimizing gear whine noise. Over the past several years there has been an effort to better understand gear whine noise source and transmission path. Based on understanding the shaft bending mode frequencies and better gear design optimization tools, the gear design was modified to increase the number of teeth in order to move out of the frequency range of the shaft bending modes at idle speed and to lower the transmission error of the gear design through optimization using the RMC (Run Many Cases) software from the OSU gear laboratory.