Date of Award

12-2009

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Mechanical Engineering

Advisor

Thompson, Lonny L

Committee Member

Ziegert , John C

Committee Member

Joseph , Paul F

Abstract

During rolling of a non-pneumatic tire, vibration may be produced by the interaction of collapsible spokes with a shear deformable ring as they enter the contact region, buckle and then snap back into a state of tension. Other potential sources of vibration include the interaction of tire tread with the ground and ring vibration. In the present work, a systematic study of the effects of key geometric design parameters is presented using Taguchi's Robust Parameter Design Method and Orthogonal Arrays.
In the present work, a 2D planar finite element model with geometric non-linearity and explicit time-stepping is used to simulate rolling of the non-pneumatic tire. Vibration characteristics are measured from the FFT frequency spectrum of the time-signals of perpendicular distance of marker nodes from the virtual plane of the spoke, ground reaction forces, and ring vibration. Both maximum peak amplitudes and RMS measures are considered resulting in a total of five output measures which are to be reduced for evaluated optimal design combinations.
In the initial study, two different L8 orthogonal arrays are considered, one with both spoke and ring parameters, and the other, which focuses on only ring variables and interactions between them. Based on the results from the initial study, an L27 orthogonal array, which combines all key geometric variables and includes the effects of uncontrollable noise factors of rolling speed and ground push up, is analyzed for robust parametric design. Since there are more than one set of noise factor combinations, Signal-to-Noise (S/N) ratios with Analysis of Variance (ANOVA) methods are used to determine percent contributions and predict the optimal combination level for each control factor, for all vibration measures.

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