Development of Input Method for Driving Road Surface Excitation Force in Road Noise CAE

Satoshi Hoshika･Takuya Aogaki･Shigemitsu Takahashi･Shusaku Iba･Hisayoshi Matsuoka (Nissan Motor)･Tatsuya Suma･Hiromichi Ebisawa (Estech)

Full vehicle analysis uses road surface data to set the excitation force to the tires in detail, which requires a lot of calculation time and makes it difficult to analyze the mechanism of the analysis results. We report that high-speed and highly accurate full vehicle analysis and factor analysis are possible by extracting the 10-degree-of-freedom excitation force that greatly contributes to road noise using principal component analysis.

Prediction of Vehicle Traveling Noise by Tire Noise Source Modeling

Hiroshi Fujii (The Yokohama Rubber)･Noriki Iwanaga (Research Center of Computational Mechanics)

In order to meet the demand for tire noise reduction accompanied with strengthen pass-by noise regulations, it is important to understand the mechanism of pass-by noise itself.
We modeled tire noise sources as monopole and dipole sound sources, estimated their strengths and positions based on the observed pressure information around several specified tires. By moving the sources, we predicted the time and frequency characteristics of sound pressure at a pass-by noise measuring point. This paper reports the comparison of the predicted characteristics with the measured ones on pass-by noise test settings.

Vibration Propagation from Main Body Structural Members to Floor Panels
-Basics for Better Road Noise-

Masao Ishihama (Ishihamagiken Consulting)

A theoretical analysis was conducted on the process of vibration transmission through a car body load carrying members to its floor panels to improve structure-borne road noise. As a result, such knowledges were obtained. 1) dispersion of vibration propagation on a door sill determines the bending vibration propagation pattern on a floor panel. 2) center of rotation of a door sill affects the floor panel bending vibration modes. These knowledges will enable us to design better floor design for low road noise.

Development of Dual Compound Insulator Improving Vehicle R&H Trade off Performance

Seung Jae Oh･Jin Hee Lee (Hyundai Motor)

R&H and NVH are trade-off and vehicles that are suitable for target performance can be developed when they are allocated appropriately considering various design requirements. In this paper, we identified the impact of front insulator on the vehicle performance and made optimum design for target performance. To achieve goal, we developed dual compound type insulator.