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Advisory Committee Chair

Vladimir V Vantsevich

Advisory Committee Members

Roy P Koomullil

David L Littlefield

Mukul K Verma

Document Type

Thesis

Date of Award

2014

Degree Name by School

Master of Science in Mechanical Engineering (MSME) School of Engineering

Abstract

In vehicles with stiff or no suspension systems, the pneumatic tires play a greater role in vibration control. The challenge is to find an approach that enhances vibratory damping in the tires without increasing the power losses due to rolling resistance effects. The goal of this thesis is to experimentally prove a novel concept of active damping within the tire while maintaining the rolling resistance found in a typical pneumatic tire. The pneumatic structure containing two chambers connected by orifices can enhance vibration damping using the force induced when air flows through the orifices. Passive damping is produced when a road disturbance and tire defection causes a pressure increase in the main chamber of the structure. This pressure increase causes airflow between the chambers and the passive damping force. Active damping in the tire can be produced by varying the pressure gradient between the chambers to change the damping force in response to the road conditions. Both passive and active damping modes will produce vibration damping without increasing the rolling resistance of the tire. The damping enhancement was evaluated by testing the pneumatic structure that simulates a pneumatic tire. The experiment was initially configured to measure the damping ratio of the conventional tire design using a calibrated external excitation and analyzing the decay of the vibration. The passive and active damping enhancement modes were then subjected to the same test and analysis procedure. Results of the analysis show that the damping enhancement measurably decreased the time of the vibratory oscillation. The damping ratio of the active damping enhancement showed an improvement of 9.4% over the baseline damping ratio.

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