Finite element method applied to 2D and 3D forging design optimization

In the forging process of complex 21) and 3D parts, multiple intermediate shapes must be used to control metal flow and/or material distribution to ensure proper filling of the finisher die. A systematic method to design an intermediate shape (known as a blocker or a preform) is especially critical for a successful outcome in the forging process. The quality of the blocker/preform design has been highly dependent upon the designer's experience. In order to minimize and ultimately remove the "experience" dependency from the design process, the objective of the current work is to investigate and develop a reliable and practical procedure to systematically carry out the blocker/preform design task. This paper summarizes the overall methodology used for both 2D and 3D preform design problems. Examples are given to demonstrate the capability of the methodology. Sensitivity analysis is used in 2D to achieve the optimal design. The objective function minimizes the variation of strain distribution within the forged component and under-filing and folding are not allowed. A procedure to couple both the filtering technique by using Fourier transform and the FEM was developed for 3D. A blocker/preform. design for a complex rib-web type model was achieved by iterating through the filtering method and the FEM simulation. In this example, an under-filing problem was eliminated.