Finite element modeling of soil compaction by liquid manure spreaders.

A three-dimensional (3-D) finite element model was developed to predict the soil compaction caused by heavy liquid manure spreaders. The model includes both material and geometric nonlinearities. The updated Lagrangian method was applied to solve the geometric nonlinearity caused by large displacements. The finite element analysis was conducted with two types of tires, two different loads, and various inflation pressures. The finite element model was verified with the field test data. The results showed that the finite element model is adequate for predicting soil compaction. In agreement with observed data, the finite element results indicated that reused airplane tires with high inflation pressure resulted in the worst soil compaction, while an agricultural high floatation tire with a smaller load and lower inflation pressure caused the least soil compaction. The finite element results also demonstrated that soil compaction can be reduced by using lower tire inflation pressure.