Session: Research Posters

Paper Number: 111270

111270 - On the Relationship Between the Vibration Characteristics of an Automobile Wheel and Generated Road Noise in the Vehicle Cabin and Resonance Noise 

The automotive industry is undergoing a major transition, and the requirements for vibration and noise performance, one of the key performance characteristics of automobiles, are changing. The relationship between tire and suspension characteristics and these noises has been the focus of attention, but the relationship with wheel vibration characteristics has not yet been studied in detail. Additionally, an automobile wheel is one of the vibration transmission paths caused by the input force from roads. Electric vehicles, which are expected to become increasingly popular, have no engine-induced vibration noise. Therefore, road noise in the vehicle cabin and resonance noise which are masked by the vibration noise caused by the engine, may become apparent and cause more discomfort to the driver and passengers than in a vehicle equipped with an ICE. Thus, the relationship between vibration characteristics of an automobile wheel and the generated these noises were investigated experimentally and numerically. Experiments were conducted using 15-inch wheels in two different vibration characteristics, and the results were discussed based on the measurements of the noise in the cabin and vibrational acceleration of the sub-frame of the vehicle when driving on smooth and rough roads at a speed of 30 km/h. Further, time response analysis using FEM was also performed using a tire–wheel assembly model. Input from the road surface is needed to perform the analysis. To determine the magnitude of the force applied from the road surface to the wheel/tire, the tire surface was vibrated with an impact hammer while the vehicle was stopped and the vibration of the lower arm was measured. The magnitude of the force applied to the wheel/tire from the road surface was estimated from the value when that value becomes the same as the vibration of the lower arm when driving at 30 km/h. In addition, particle velocity measurements were also performed on another two wheel types at 300 mm from the center of the wheel using the Voyager and a particle probe and sound pressure levels around these wheels were compared using harmonic acoustics analysis. Of the two types of wheels, one is identical to the wheel shape described above, and the other is based on that wheel with the same mass and a modified shape, which was prototyped with the aim of reducing vibration noise. The analyzed frequencies were 250 Hz, 500 Hz, 750 Hz, 1000 Hz, and 1250 Hz, which were peaked in the graphs obtained in the experiment. For the analysis, PML and acoustic regions were created, and they were connected and analyzed by multibodying. The results showed that large differences were observed in the generated noise of 49, 90, and 167 Hz in the case of the smooth road, and these differences were due to the difference in the magnitude of vibrational accelerations of the wheel at these frequencies. In addition, the analysis revealed that the loudness of the sound around the wheel confirmed qualitative consistency with experimental results. The results indicate that changing the wheel shape, specifically a shape with no curvature in the out-of-plane direction, may reduce vibration at 49 Hz, 90 Hz, and 167 Hz, as well as road noise and resonance noise at those frequencies. In addition, the number and thickness of spokes on the wheel may also affect these noises.

Presenting Author: Sho Kobayashi Toyama Prefectural University

Presenting Author Biography: Sho Kobayashi received the B.E. degree from Toyama Prefectural University Japan, in 2023. He is now in the graduate school of Mechanical Systems Engineering in Toyama Prefectural University. He specializes in noise and vibration. He is a member of the Society of Automotive Engineers of Japan and the Japan Society of Mechanical Engineers.

Authors:

Sho Kobayashi Toyama Prefectural University
Ryo Kiyotaki Toyama Prefectural University
Li Zhe Toyama Prefectural University
Osamu Terashima Toyama Prefectural University