Issue 43

P. Zampieri et alii, Frattura ed Integrità Strutturale, 43 (2018) 191-204; DOI: 10.3221/IGF-ESIS.43.15 201 N UMERICAL - EXPERIMENTAL RESULTS n order to save the computational costs an artificial mass has been added to the model in a way that the whole model mass does not reach the 8÷9%, as shown in Fig. 18. Fig. 19 shows the energies balance. In particular, kinetic, hourglass, interface, internal and total energies are shown. According to Fig. 19, the kinetic and internal energies are characterized by two analogous picks. Such picks are due to the fluctuation of the tyre inflation. The hourglass energy is null for all the analysis. Figure 19 : Energies balance. Also the tyre inflation has been monitored by plotting the tyre tube pressure as a function of the analysis time (Fig. 20.a). It can be noticed that the pressure starts by a value of 0 and reaches instantly the reference value of 8.5 bar. Fig. 20.b shows the volume of the tyre tube during the drop test simulation. Figure 20 : a) Pressure and b) volume tyre tube vs. time. I