Equalization of Natural Frequency Spacing in Panel Design

Rui Yamada (Gifu University)･Keizo Konishi･Kunito Iida (Honda R&D)･Yuichi Matsumura (Gifu University)

When designing structures such as automobiles, the natural frequencies of each subsystem are generally separated from one another to prevent significant changes in the natural frequencies after assembly. In this study, we investigated a method to equalize the intervals between the natural frequencies of a panel-like structure without making structural modifications, by optimizing the placement of spot welds.

A method for reducing blocked force by sparse structural modifications

Tatsuki Morishita (Gifu University)･Yuki Kato (Kochi University of Technology)･Yuichi Matsumura (Gifu University)

In this study, we developed a method to reduce Blocked force by modifying the structure of the excitation subsystem to reduce the response of the passive subsystem. By employing sparse modeling, we minimized the extent of the structural modifications and reduced their impact on the whole structure. This presentation reports the results of applying the proposed method to a finite element model.

Extension of a Tire/Road Noise Model Accounting for Two Peaks of Accelerated Pass by Noise Level

Naoki Suzuki･Yoshihiro Shirahashi･Toru Yamazaki･Yukari Iwaizumi (Kanagawa University)･Masayuki Wada･Daisuke Morie (Nissan Motor)

Conventional models of tire-road noise under acceleration have mainly focused on noise generated at the tire trailing edge. In this study, the model is extended to include noise generated at the leading edge, focusing on the bimodal characteristics observed in pass-by noise during acceleration. The applicability of the proposed model was verified using multiple tires. The results show that the leading edge noise can also be modeled based on elastic energy and that the extended model is effective for evaluating vehicle exterior noise.

Development of a Technology for Enhancing Effective Felt Mass and Transmission Loss via Low-Stiffness Region Control in Automotive Double-Felt Soundproofing Materials

Kanta Kasama･Ryoji Morisaki･Shinichiro Iwai (Hirotani)

A technique for improving transmission loss (TL) in automotive double-felt soundproofing materials was developed by controlling the low spring constant region between the sound-absorbing felt and the film. Furthermore, a prototype dash insulator incorporating this technique was fabricated, and its effectiveness was validated through in-vehicle evaluation

Experimental Characterization of Vibration Properties of an MG Stator Structure with a Laminated Core and Resin Fixation Using Simplified Test Specimens

Shingo Aoki･Hiroshi Hashimoto･Yusuke Sawamura (Toyota Motor)

To achieve lean development of motor NV performance, prototype-free approaches are being pursued; however, the prediction accuracy of vibration characteristics for MG stator structures with laminated cores and resin fixation materials remains a challenge. In this study, experimental verification using simplified test specimens was conducted, focusing on the deformation behavior of laminated cores. As a result, vibration characteristics and shape effects were clarified, and high-accuracy prediction of vibration characteristics was achieved by incorporating these findings into the model.