John L. Turner

Measuring the complete surface strain field on rubber structures using an optical method.

A method for determining the complete surface strain field on rubber structures is described. The technique consists of photographically depositing a set of grid lines on the surface of a photoelastic birefringent coating. The coating is bonded to the surface of the object of interest. Photoelastic data together with grid photographs provide sufficient information for determining the complete surface strain state at all points on the coating. An experimental example demonstrating the technique is presented. The technique is especially well suited for strain measurements in the range from 1% to 10%-a range commonly encountered with pneumatic tires.