Multi-objective optimization of process parameters in cold forging minimizing risk of crack and forging energy

In this paper, a typical cold forging process using spring-held die is considered, in which the process parameters such as stiffness of spring, the initial loads and the punch speed are conventionally adjusted by the trial-and-error method for high product quality. The target product has the earing, around which the crack is often observed by the conventional process parameters. To avoid the crack around the earing, the process parameters optimization is performed through numerical simulation using DEFORM3D, in which two objective functions are considered. The risk of crack is numerically evaluated and is minimized, whereas the total forging energy using the load-stroke diagram is also minimized. Therefore, the multi-objective design optimization is performed. The numerical simulation is so intensive that sequential approximate optimization using radial basis function network is adopted to identify the pareto-frontier between the objectives with a small number of simulations. Compared with the product using the conventional process parameters, the optimal process parameters can reduce both the risk of crack and the total forging energy. In addition, the flow lines along the product shape can be obtained by using the optimal process parameters. Based on the numerical result, the experiment using the mechanical press (IST100W, ITO) is carried out. No crack is observed in the experiment, and then the validity of the proposed approach is confirmed.

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Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023)