Incremental Grooving of Thin-Walled Tubes Filled with Discrete Media

To control the undesired deformations like section-distortion and springback during incremental tube wall grooving, we examined the effect of discrete fillers on the deformation of thin-walled tubes during forming. Al6061 tubes with outer diameter of 38 mm and thickness of 1 mm were used in the studies, with silica sands as the fillers. Generalized plastic mechanics was employed to analyze the coupled deformation of the composite structures of discrete media filled tubes; the aggregation of sands was assumed to be compressible continuous body, of which yield behavior was described by the Drucker–Prager criterion. The results proved that compared with hollow tubes, the forming accuracy of incremental tube grooving can be improved under the support of fillers. Specifically, the maximum springback was reduced by more than 3.9%, and the section-distortion also decreased. Moreover, a special deformation mode, the prism-shape distortion, was found to occur when the tool feeding step was large.