A 3-DIMENSIONAL UPPER BOUND ELEMENTAL TECHNIQUE FOR FORGING ANALYSIS

In this paper, two kinematically admissible velocity fields are derive d for the proposed three-dimensional arbitrarily triangular and trapez oidal prismatic upper bound elemental technique (UBET) elements. These elements are applied to the portions between the circular shaped part and the straight rod part with three-dimensional metal flow in connec ting rod forging, and then the capability of the proposed elements are shown. From the derived velocity fields, the upper bound loads on the upper die and the velocity field are determined by minimizing the tot al energy consumption with respect to some chosen parameters. Experime nts with connecting rod forging were carried out with commercial pure lead billets at ambient temperature. The theoretical predictions of th e forming load is in good agreement with the experimental results. It is shown that the proposed UBET elements in this work can effectively be used for the prediction of the forming load and velocity field in c onnecting rod forging.