Vibroacoustic Response of Flexible Car Components
J. Herrmann;  M. Junge;  L. Gaul

Source CMES: Computer Modeling in Engineering & Sciences, Vol. 86, No. 6, pp. 487-504, 2012
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Keywords acoustic fluid-structure interaction, FEM, substructuring, model reduction, dynamic measurements.
Abstract The influence of an acoustic field on the dynamic behavior of a flexible structure is a common issue in automotive applications. An example is the pressure-induced structure-borne sound of piping and exhaust systems. Efficient model order reduction and substructuring techniques accelerate the finite element analysis and enable the vibroacoustic optimization of such complex systems with acoustic fluid-structure interaction. This research reviews the application of the Craig-Bampton and the Rubin method to fluid-structure coupled systems and presents two automotive applications. First, a fluid-filled piping system is assembled by substructures or superelements according to the Craig-Bampton method. Fluid and structural partitions are fully coupled in order to capture the interaction between the pipe shell and the heavy fluid inside the pipe. Moreover, a fluid-filled corrugated pipe is efficiently modeled and analyzed. Second, a rear muffler with an air-borne excitation is investigated. Here, the Rubin and the Craig-Bampton method are used to separately compute the uncoupled component modes of both the acoustic and the structural domain. These modes are then used to compute a reduced model that incorporates full acoustic-structure coupling. For both applications, transfer functions are computed and compared to the results of dynamic measurements.
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