Riassunto analitico
This thesis presents a methodology for identifying tire characteristics through the parametric fitting of a modified Fiala model, known as the CP/SATP model. This model enhances the classical Fiala formulation by incorporating tread shear, in-plane belt deflection, and sidewall torsion, improving accuracy for modern radial tires.
The aim is to estimate key stiffness parameters (tread, belt and sidewall stiffness), using experimental data from flat-track tests conducted on various tire types under different loads and configurations. A two-step optimization was employed: a genetic algorithm for global exploration followed by refinement using the Levenberg-Marquardt-based lsqnonlin. The objective function minimized the normalized root-mean-square error between measured and modeled lateral force and aligning moment.
The analysis of fitted parameters under varying conditions (e.g., inflation pressure, compound stiffness, belt angle) revealed their sensitivity to tire structure and load. Deformation ratio analysis quantified the relative impact of each modeled mechanism, showing increased influence of belt and sidewall deformation with vertical load. Sensitivity and uniqueness studies validated the robustness of the solution.
A final load-dependent study of each parameter highlighted trends supporting the development of physically meaningful tire models. Although this work does not yet fully enable tire discrimination based on single construction differences, it lays the foundation for future applications.
Overall, the CP/SATP model, combined with the proposed identification framework, offers a reliable path toward bridging experimental tire behavior and structural interpretation, with promising applications in simulation, control, and design.
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