Numerical Simulation of Tire-Ground System Considering Soft Ground Characteristics

Abstract

The dynamic characteristics and behavior of soft ground are greatly affected by the constituent soil grain shape. For multipass calculations of the action of tires on soft ground, it is important to take into consideration the elastic-plastic properties of the soil. We previously developed an efficient interactive model of a tire and soft ground that comprises a distributed lumped mass-spring model for the tire, a discrete element model for the upper ground section, and a mass-spring model for the lower ground section. In the present study, we have improved the previous soft ground model by considering the soil grain shape and the elastic-plastic properties of soft ground, and have analyzed the effect on the behavior of the tire and soft ground using numerical simulations. The results showed that soft ground composed of non-round soil grains exhibits higher shear strength and stability than is the case for round grains. In addition, it was found that the reversal of sinkage following the passage of a tire and the compaction due to multiple tire passes could be expressed qualitatively by modeling the elastic-plastic properties of the lower soft ground section.