An analytical approach for modelling incremental disk rolling process

Abstract

Abstract. In the context of the current study, an analytical method is developed to determine the deformation field of the workpiece under the forming roller for an unconventional incremental radial disk rolling (IRDR) process. As the industrial forming machine is in the development phase, the machine and process design requires a preliminary assessment tool that is sensitive to process parameters and roller geometry. Establishing a parametric relationship between process parameters and induced deformation field enables designers to determine the parameters needed to obtain the target geometry and microstructure as well as the forming machine requirements. Instantaneous roller-workpiece interface, i.e. contact zone, and cross-sections that plastic flow occurs in between are calculated. The contact zone is spatially discretized to two-dimensional surface elements. The principle of volume conservation during plastic deformation is utilized to obtain velocity fields in three dimensions. Strain rate distributions are calculated by taking the gradient of the velocity fields in respective directions. Average values of strain at each cross-section are the accumulated plastic strain that is created by the multiple circumferential passes of the roller and computed numerically, accounting for different strain rates and contact times at each pass. Obtained contact zone geometries, deformation fields, and the effect of different process parameters are discussed. Results show that deformation occurs mainly in the circumferential direction and the tangential velocity of the roller in the circumferential direction has a more pronounced effect on the deformation than the radial advance of the roller per revolution.