Pillinger, Ian (1984)
Ph.D. thesis, University of Birmingham.
 AbstractA knowledge of the flow occuring in metalforming processes is of great industrial importance, and the finiteelement technique is the only form of deformation analysis which can predict the flow of the material. The examination of forging operations requires a full elasticplastic treatment to be used. This thesis is concerned with an elasticplastic, finiteelement program which has been developed to investigate threedimensional examples of this process. The fundamental theory of the finiteelement method is first introduced, and then the finiteelement program is described in detail. The deformation, and distributions of hardness and dieinterface pressure, predicted by this technique for the unlubricated upsetting of a rectangular block are compared with experimental results, and found to be in broad agreement, the differences being attributed to the incorrect imposition of very high friction by the frictionlayer technique used in the analysis. With a corrected form of the friction technique, the finiteelement program predicts results for the axisymmetric frictionring test and a new threedimensional friction test which are in good agreement with experimental findings up to deformations of approximately 30%; the frictionlayer technique used successfully in previous axisymmetric treatments appears to be unsuitable for threedimensional formulations when large deformations are considered. The finiteelement program developed here is shown to be capable of modelling an example of a more complicated threedimensional forging, that of an automobile connnecting rod. The experimental measurements of cteformation and hardness for an aluminium con rod forged using graphite lubrication are found to be in good agreement with the finiteelement predictions obtained assuming sticking friction conditions but not with the results of a zerofriction idealisation. Finally, suggestions are made for the future development of this technique.

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