We model SPPs as a concentrated suspension of elastic spheres. The particles are packed against one another and interact though strong elastohydrodynamic lubrication forces generated due to compression and relative motion between them. The 3D molecular dynamics-like simulations capture the particle dynamics and also its effect on bulk rheology. Constant stress and constant shear-rate simulations are used to define the complete stress tensor of these materials. The simulation results for the yield, shear and normal stresses are presented as function of concentration and the ratio of viscous to elastic forces. The macroscopic rheology of these materials is related to the microstructural changes that occur during and upon cessation of flow. The theoretical predictions of the bulk rheology are found to compare favorably to previous experimental observations.