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With the advent of the electrification era, rolling noise is set to become a dominant source of noise for electric vehicles due to the phasing out of the internal combustion engine. The vibrations generated by tire-road interaction are transferred through the wheel center to the knuckle and subsequently through the vehicle cabin. With the advance of the simulation techniques, the description of tire operational phenomena has improved. However, some limitations are present. These include low computational efficiency in a full-vehicle simulation and absence of direct validation with the real tire in the same operational conditions. Siemens Digital Industries Software currently offers a lightweight combined test and model-based solution for tire NVH for the assessment of structure-borne noise. The aim of this paper is to demonstrate the potential of a pragmatic approach able to capture the static tire dynamic behavior up to 300 Hz.

Target setting at Body-In-White (BIW) level is typically done for natural frequencies of global modes. Target values are commonly set based on experience or from benchmark studies with competitor vehicles. A link between these targets at BIW level and the vibro-acoustic targets at Trimmed Body (TB) level is not yet well established. Therefore, it is not always guaranteed that the TB targets will be met when the targets at BIW level are reached. Also, the other way around, not reaching a frequency target for a certain BIW mode does not necessarily imply that TB targets will not be met. Hence, there is a clear need for getting more insights in the relation between BIW dynamic properties and TB vibration behavior. In this paper techniques will be presented that establish the link between BIW and TB dynamic behavior. In addition, a large DOE campaign has been carried out to further link these dynamic properties to specific areas in the body design.

This paper reports on test-analysis correlation and model updating activities carried out in the context of the European research project “HPC-VAO” (ESPRIT Project nr 20074, High Performance Computational environment for Vibro-Acoustic Optimisation). The central aim of the project is the implementation of a state-of-the-art CAE environment to support design optimisation in the field of NVH engineering. A specific objective covers the validation of the simulation models that are used in the vibro-acoustic optimisation framework. The validity and reliability of these models can be drastically improved by application of ‘model updating’ techniques. Whilst much research has been done in this field in the last decade, the number of cases where the technique has been used on industrial applications are slowly but steadily growing.

This paper presents a model updating method based on experimental receptances. The presented method minimises the so called ‘indirect receptance difference’. First, the reduced analytical dynamic stiffness matrix is expressed as an approximate, linearised function of the updating parameters. In a numerically stable, iterative procedure, this reduced analytical dynamic stiffness matrix is changed in such a way that the analytical receptances match the experimental receptances at the updating frequencies. The updating frequencies are a set of selected frequency points in the frequency range of interest. Some considerations about an optimal selection of the updating frequencies are given. Finally, a mixed static-dynamic reduction scheme is discussed. Dynamic reduction of the analytical dynamic stiffness matrix at each updating frequency is physically exact, but it involves a great computational effort.

This paper presents two applications of the RADSER model updating technique (ref. 1). The RADSER technique updates finite element model parameters by solution of a linearised set of equations that optimise the Reduced Analytical Dynamic Stiffness matrix based on Experimental Receptances. The first application deals with the identification of the dynamice characteristics of rubber mounts. The second application validates a coarse finite element model of a subframe of a Volvo 480.

The prediction of the acoustic radiation of vibrating structures is traditionally based on the acoustic boundary element method. This approach leads to good predictions, provided that the dynamic behavior of the system is well known. This paper presents the integration of experimental vibration analysis with numerical acoustic radiation prediction. The developed methodology involves several steps: (i) measure the accelerations on the surface of a vibrating body, (ii) expand these experimental data onto a numerical model, using the modal information of a finite element model, and (iii) run a boundary element analysis to determine the acoustic radiated field. This procedure presents the advantages that the dynamic behavior is as accurately as possible defined and that the boundary element approach opens wide results interpretation (contribution and sensitivity analysis…). A real-life application example (car engine) is shown to illustrate and validate the developed methodology.