During lift operations cylindrical or spherical payloads may roll against objects in the surrounding environment. Additionally, if multiple payloads are lifted simultaneously, they may roll against each other as seen below.
During this rolling contact some energy is dissipated as a result of local deformation of the bodies at the contacting surfaces. An exaggerated example of this local deformation for rolling contact between two circular bodies is seen below.
A model for rolling contact between two bodies has been developed that yields solutions for the tangential and normal components of the contact forces. The behavior of the model has been investigated under conditions of planar rolling with forced acceleration, forced deceleration, forced constant velocity rolling, and unforced deceleration (free rolling). The observed behavior of the rolling disk in these simulations appears to show realistic rolling behavior for these scenarios. Additionally, the simulated results for rolling contact between two pinned, identical disks under unforced deceleration match expected behavior.
Additional work is underway to evaluate the conditions under which slip will occur and investigate the appropriateness of the derived model when a rolling body has multiple contact points.