SUMMARY

An apparatus is designed to investigate contact mechanics of elastomeric rollers interfacing with a rigid substrate, and digital image correlation is applied to extract novel multi-plane quasistatic strain fields of a roller under progressive normal and tangential loads. The apparatus allows multiple loading configurations ranging from static normal and tangential loading of the roller to free rolling and rolling with a propulsive or a braking torque. The instrument can be used to gain insight into local and global roller mechanics since it has the ability to simultaneously obtain force and displacement data from sensors as well as optical measurements and local deformation fields across two different planes through the use of digital image correlation. Apparatus functions, elements, and design are presented in detail, and its capabilities are demonstrated by obtaining measurements such as width of the contact interface under normal loading, the roller’s resistance to motion for free and forced rolling, and strain fields of the roller sidewall and contact interface. The evolution of strain in the two planes is tracked as normal load on the roller increases, followed by an increasing tangential load. Strain fields referenced to an undeformed roller and to a roller under the maximum normal load are presented and discussed.