Session: SYMP 5-3: SHM for Extreme Load Applications

Paper Number: 140422

140422 - Sensitivity Analysis of Tire Modal Characteristics in Unloaded Conditions Relative to Inflation Pressure 

Tire/road interaction is a fundamental operative parameter for vehicle manufacturers, having a significant impact on riding comfort and noise levels in automobiles. The structural vibrations induced by road irregularities and variations in brake torque give rise to dynamic behaviors in tires, which significantly affect riding comfort and noise levels. This necessitates a thorough understanding of their modal characteristics to optimize overall tire performance. This study employs experimental modal analysis techniques to provide a comprehensive insight into the dynamic behavior of tires. The well-established experimental modal analysis techniques yield modal characteristics (natural frequencies, damping ratios, and mode shapes) of the system which play an important role in analyzing the system's dynamic behavior. The vector fitting algorithm has been used to estimate these modal characteristics from the response of the tire system.

The primary objective of this paper is to assess the sensitivity of tire modal characteristics in an unloaded condition relative to inflation pressure, with a specific focus on the first six fundamental flexible modes, typically occurring in the frequency band of 0-150 Hz. The study follows the SAE recommended practice, utilizing an unloaded spindle configuration for experimentation. A roving impact hammer test is performed by impacting the tire at multiple locations and the acceleration response is measured using strategically placed accelerometers generating Frequency Response Functions (FRFs) characterized by well-separated resonant peaks. The tire is subjected to various inflation pressures and the impact hammer test is repeated for each case. This enables a comprehensive examination of the tire's modal behavior under different conditions. Following the test, modal characteristics are estimated using the experimental data.

The outcomes of this tire modal analysis reveal significant variations in modal characteristics corresponding to variations in tire pressures. As the tire pressure transitions from 10 psi to 40 psi, noticeable changes appear in the modal characteristics owing to alterations in mass and stiffness properties of the tire. These findings underscore the critical role of tire pressure as an important parameter in understanding and optimizing the riding comfort and noise levels within vehicles.

Through rigorous testing, the tire testing methodology utilized in this study can be used to predict the dynamic behavior of tires under different loading conditions. A comprehensive understanding of the tire modal characteristics in response to inflation pressure facilitates informed decision-making for designing tires. Coupled with other tire performance test practices in the industry, the approach used in this study will prove to be effective in significantly improving tire performance.

Presenting Author: Hrishikesh Gosavi Michigan Technological University

Presenting Author Biography: I am a Ph.D. candidate at Michigan Technological University under the guidance of Dr. Sriram Malladi. I am from India and I completed my undergraduate studies there. I have been at Michigan Tech since Fall 2019. My research interests include metastructures, FRF-based substructuring, and experimental modal analysis.

Authors:

Hrishikesh Gosavi
Allen Basker
Ratnajeet Wadile
Vijaya v. N. Sriram Malladi