DIC analysis of gears in bending condition

Abstract

Thin rim gears present a complex strain and stress field due to its particular geometry, above all in bending problems. From this point of view, the position of the most stressed point and the corresponding equivalent stress value are useful for an accurate design of thin rim gears. More in detail, in case of bending failure, both crack initiation point and corresponding propagation path are strictly related to the gear’s geometry. In this work, an experimental analysis was performed to evaluate how light weight gears geometry may influence the strain field close to the tooth root. To this aim, an experimental activity was carried on by a dedicated equipment for bending tests and the gear deformation was monitored by using the 3D Digital Image Correlation (DIC) technique. The local strain field in both tooth and web portions was measured for two types of gears (standard gear and thin-rim gear) in order to identify the stress condition due to the bending loading. A particular attention was devoted to point out the most stressed point for both gears. Results were also compared with XFEM model available in literature.