An Experimental–Numerical Approach for Modelling the Mechanical Behaviour of a Pneumatic Tyre for Agricultural Machines

settings Open AccessArticle An Experimental–Numerical Approach for Modelling the Mechanical Behaviour of a Pneumatic Tyre for Agricultural Machines by Alexandros Sotirios Anifantis 1OrcID,Maurizio Cutini 2OrcID andMarco Bietresato 3,*OrcID 1 Department of Agricultural and Environmental Science, University of Bari Aldo Moro, via Amendola 165/A, I-70126 Bari (BA), Italy 2 Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria (CREA)-Centro di ricerca Ingegneria e Trasformazioni agroalimentari (CREA-IT), via Milano 43, I-24047 Treviglio (BG), Italy 3 Faculty of Science and Technology, Free University of Bozen/Bolzano, Piazza Università 5, I-39100 Bolzano (BZ), Italy * Author to whom correspondence should be addressed. Appl. Sci. 2020, 10(10), 3481; https://doi.org/10.3390/app10103481 Received: 20 April 2020 / Revised: 11 May 2020 / Accepted: 14 May 2020 / Published: 18 May 2020 (This article belongs to the Section Mechanical Engineering) Download PDF Browse Figures Abstract The mechanical behaviour of an agricultural tyre is a matter of extreme interest as it is related to the comfort of operators, to the adherence of agricultural machines, and to the compaction of agricultural soil. Moreover, the deformability of the tyres plays a fundamental role in vehicle stability in terms of side rollover. The behaviour of a loaded tyre during its deformation is complex, due to the combined contributions of the carcass components, the tread rubber and the air contained within it. Therefore, this study proposes an experimental–numerical approach for the mechanical characterization of agricultural tyres based on real-scale experiments and matches these results with a finite-element (FE) model. The tyre flattening in the elastic field has been described using two coefficients (Young’s modulus “E”, Poisson’s ratio “ν”), whose values have been identified with an iterative FEM procedure. The proposed approach was applied to two different tyres (420/85 R24 and 460/85 R34), each one inflated at two different pressures (1.0 bar and 1.6 bar). Young’s modulus was appreciated to be highly variable with the inflation pressure “p” of the tyres. Furthermore, the response surface methodology was applied to find two mathematical regression models, useful for studying the variations of the tyre footprint dimensions according to the type of tyre. This simple approach can be applied in other simulations without suffering any loss of accuracy in the description of the phenomenon.