Search Results

Structural and vibro-acoustic transfer functions still form an essential part of NVH data in vehicle development programs. Excitation in the three DOFs at all body interface connection locations to target responses gives information on local dynamics stiffness and the body sensitivity for that specific path in an efficient manner. However, vehicles become more compact for fuel efficiency, production costs and to meet the market demand for urban vehicles. Alternative driveline concepts increase the electronic content and new mount locations. To achieve the optimum on road noise NVH, handling performance while conserving interior space and trunk volume requires a complex suspension layout. On top of that, customers put weight on safety and comfort systems which result to a higher packaging density. These trends imply ever limiting accessibility of the interface connections on the body structure.

The need for more durable mobility has led to a rapid introduction of new electric systems on vehicles. The result of the application of electrified drivelines is a shift in noise energy from the low mid frequencies towards the upper end of the audible range. Following this, the need for higher frequency noise control and accurate measurement has grown. The measurement of the acoustic transfer or vehicle body isolation at higher frequencies poses a challenge for the diffraction, source level and omni-directionality. This paper shows an improved method that increases the accuracy of acoustic transfer function measurements from the components to the ear at high frequencies. A simulation model based on the Boundary Element Methods(BEM) has been made to analyze higher frequency behavior of noise sources during reciprocal measurements up to 12 kHz. Some dedicated hardware was developed in combination with a new process.