Full Vehicle Virtual Acoustic Prototyping using Test-Based models and Blocked Force descriptions 2023-01-1085
Vehicle Acoustic Prototyping in the mid to high frequency range is challenging with numerical models only. To overcome this challenge, over the past decade, experimental techniques were developed that allow the engineer to incorporate Test-Based models in their (numerical) simulation as well. Using Virtual Point Technology these Test-Based models serve well to describe, for example, the complex dynamics of the vehicle body Noise Transfer Functions. Here the high modal density and damping characteristics are simply measured on a mule or prototype vehicle and coupled to numerical models of the drivetrain using Dynamic Substructuring. As such accurate predictions and/or risk assessments can be made much earlier in the mid and high frequency range during the vehicle development stage.
While test-based models serve well to describe the coupled vehicle dynamics, loads to compute actual vehicle responses are needed as well. Here, so-called Equivalent or Blocked Forces are ideal as they are found to be independent of the vehicle dynamics. This means they will remain the same while entering virtual Dynamic Substructuring optimization of the vehicle components with respect to their effect on the noise at the driver’s ears.
This paper introduces the technical concepts mentioned with focus on the benefits and merits with an example case of an electric vehicle’s E-compressor.