Issue 43

P. Zampieri et alii, Frattura ed Integrità Strutturale, 43 (2018) 191-204; DOI: 10.3221/IGF-ESIS.43.15 198 Figure 11 : Secondary actuation system. Another constraint type, shown in Fig. 12, has been defined in order to ensure the motion between the wheels and the axle. Figure 12 : Modelling of the joints between wheels and axle. Figure 13 : Modelling of the rigid wall. A rigid wall (Fig. 13), representing the ground, has been also modelled in order to simulate the drop test. Also here, “contact-automatic-surface-to-surface” algorithm has been defined between the rigid wall and the tyres. In order to simplify the drop test simulation, the landing gear has been fully constrained; whilst the rigid wall has been constrained in a way to enable its motion only along the drop test axis (z-axis). Concerning the modelling of the tyre, the same technique used to model the airbag in the automotive field, has been used. It is, in fact, and efficient method, usable to model the tyres. Such modelling started to the definition of a closed surface containing a control volume (Fig. 14). Such volume represents the tyre tube which has been numerically inflated by introducing a mass flow rate up to reach the desired pressure value (8.5 bar).