Experimental-numerical comfort analysis of a heavy-duty vehicle.

The Master Thesis work has been conducted in the Iveco headquarter in Turin (Italy) with the supervision of the Polytechnic of Turin. It has the aim to develop a reliable multibody model of a heavy-duty vehicle (Iveco Stralis), capable to faithfully reproduce on-road tests. In automotive market, today more than in the past, it is very important to reduce time to market and, mostly, developing costs. So, it is essential to have very accurate models, able to forecast on road behaviors. The multibody environment used is Adams/Car, produced by MSC Software, while Matlab is chosen for the post-processing environment. Furthermore, a complete 3D model was available in CATIA, and Altair Hypermesh, MSC Nastran and MSC Adams/View are used to create flexible bodies. After the introduction, where an overview of the company and of the truck is given, the work is mainly divided in four parts. The first one is aimed at the tuning of the existing multibody model, in order to obtain a complete and updated model, as close as possible to the real one, from the geometrical and the mechanical point of view. Subsequently, the preparation of the multibody model for simulations is presented. In this chapter FTire model, OpenCRG track format and Adams/Solver settings are discussed. The third part concerns the simulation data and experimental data investigation, in time and in frequency domain, using level crossing method and PSD analysis. The final part regards some considerations on the obtained results and the future perspectives of this project that surely will not stop here and now.