Methods, Models, and Assumptions Used in Finite Element Simulation of a Pilger Metal Forming Process

The pilger process is a cold-worked mechanical process that combines the elements of extrusion, rolling, and upsetting for the formation of thin-walled tubes. This complex manufacturing process relies on the results of trial and error testing programs, experimental parameter sensitivity studies, and prototypical applications to advance the technology. This finite element modelling effort describes the methods, models, and assumptions used to assess the process parameters used to manufacture thin-walled tubing. The modelling technique breaks down the manufacturing process into smaller computer generated models representing fundamental process functions. Each of these models is linked with the overall process simulation. Simplified assumptions are identified and supporting justifications provided. This work represents proof of principle modelling techniques, using large deformation, large strain, finite element software. These modelling techniques can be extended to more extensive parameter studies evaluating the effects of pilger process parameter changes on final tube stress and strain states and their relationship to defect formation/propagation. Sensitivity studies on input variables and the process parameters associated with one pass of the pilger process are also included. The modelling techniques have been extended to parameter studies evaluating the effects of pilger process parameter changes on tube stress and strain states and their relationship to defect formation. Eventually a complex qualified 3-D model will provide more accurate results for process evaluation purposes. However, the trends and results reported are judged adequate for examining process trends and parameter variability.