A 3D multibody model of an agricultural vehicle operating on a deformable soil: numerical investigation of the vertical dynamics

The paper presents an analysis of the vertical dynamics of an agricultural tractor focused on the influence of suspensions’ parameters on riding comfort and on contact forces. The analysis is performed by means of a 3D multi-body model whose parameters were identified by comparison with experimental data gained through a four-poster test bench. The model was interfaced with a contact model which allows to take into account the soil’s deformation and the tread pattern design. Numerical simulation were carried out considering tillage operations on a deformable soil with different tunings of suspensions’ damping and with two different commercial tires; in particular damping of seat, cabin and front suspensions were changed to determine the possible improvement of riding comfort and the effect on the variations of contact forces.