Roadnoise Reduction through Component-TPA with Test and Simulation Convergence Using Blocked Force

Abstract

While conventional methods like classical Transfer Path Analysis (TPA), Multiple Coherence Analysis (MCA), Operational Deflection Shape (ODS), and Modal Analysis have been widely used for road noise reduction, component-TPA from Model Based System Engineering (MBSE) is gaining attention for its ability to efficiently develop complex mobility systems.In this research, we propose a method to achieve road noise targets in the early stage of vehicle development using component-level TPA based on the blocked force method. An important point is to ensure convergence of measured test results (e.g. sound pressure at driver ear) and simulation results from component TPA.To conduct component-TPA, it is essential to have an independent tire model consisting of wheel-tire blocked force and tire Frequency Response Function (FRF), as well as full vehicle FRF and vehicle hub FRF. In this study, the FRF of the full vehicle and wheel-tire blocked force are obtained using an in-situ method with a precedent vehicle. The tire FRF is then obtained using the FBS (Frequency Based Substructuring) decomposition method after measuring the vehicle’s hub FRF. The consistency of the measured interior noise with the interior noise calculated through the component-level TPA is verified.Furthermore, in virtual development for future vehicle models, the interior noise of the virtual vehicle can be predicted by converging the early-stage vehicle CAE model, such as the architecture or Preliminary Design Stage, with the independent tire model from internal database or provided by tire suppliers. The spindle load (wheel input load) of the vehicle, that is calculated using the equation derived from the component-level TPA, is used as excitation. Based on this interior noise prediction, technical measures to reduce the interior noise and vibration level can be considered through alternative designs that reduce the wheel input load, the sound transmission or avoid the sensitive frequency bands.