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2016
Conference Paper
Titel
Reducing rear axle gear whine noise inside a car by influencing the structure-borne sound transfer path using structurally integrated piezo-actuators
Alternative
Reduktion des Hinterachsheulens im Fahrzeug mit Hilfe von strukturintegrierten Piezoaktoren zur Maunipulation von Körperschalltransferpfaden
Abstract
The gear whine noise of rear axles is a well-known acoustic phenomenon especially for rear-wheel and four-wheel drive vehicles. The acoustical optimization of this problem leads to the major goal conflict: improvement of the vibrational isolation of the rear axle versus excellent driving dynamics of the vehicle. A possible solution for this issue is in focus of a research project at Fraunhofer Institute for Machine Tools and Forming Technology IWU in cooperation with Mercedes AMG GmbH. The aim is to reduce the noise contributions of the rear axle inside the car using an active vibration control system on the transfer path from the axle into the vehicle based on structurally integrated piezo-actuators. This paper describes the development process of the active vibration control system. At first, a FEM-simulation model has been created which is able to represent the operational deflection shapes of the rear axle assembly in critical operating points. In a next step, two simulation approaches have been applied in order to identify promising excitation points for an actuator application: the structural intensity analysis and a sensitivity analysis of transfer functions of the rear axle structure. Furthermore, the geometry and material properties of the piezoactuator have been implemented in the simulation to calculate the force reduction on the coupling points to the vehicle body. In addition, a rear axle test bench has been set up in order to reproduce the operational deflection shapes and validate the simulation results.