Numerical analysis of the effect of tire characteristics, soil response and suspensions tuning on the comfort of an agricultural vehicle

• A model for the interaction between tire and soil has been set up.
• The soil has been modeled by a spring layer, reacting to the tire sinkage.
• The contact surface has been computed according to the tread pattern geometry.
• The comfort performances of tractor-tire system over different soils have been evaluated.
• Effect of suspensions on comfort is analyzed.

The paper focuses on the numerical investigation of riding comfort of an agricultural vehicle. The analysis is carried out combining a multi-body model of a tractor with a tire–soil interaction model. The multi-body model schematizes the tractor through several rigid bodies representing the chassis, the cabin, the seat and the tires. Model parameters (masses, suspension parameters) were identified by means of full scale tests on a four-post test-rig. Tire–soil interaction model allows computation of the forces exchanged at the contact interface considering soil deformability and the 3D tread design. Several simulations were performed considering the vehicle running at constant speed over a deformable soil; different combinations of suspensions parameters were analyzed to determine their effect on driver comfort evaluated in terms of vertical acceleration on the seat. In addition, the analysis was completed with four different scenarios coupling two different tires with two different soils.