Springback prediction for a mechanical micro connector using CPFEM based numerical simulations

The bending process of an industrial connector is considered and investigated via numerical simulation using a crystal plasticity finite element model (CPFEM). The process consists of sequentially bending a 0.1 mm thick copper-based alloy (CuBe2) with progressive tools into a miniature cylindrical connector of around 1 mm in diameter. The paper focuses on the prediction of springback through the influence of several key-parameters of the numerical simulations. The finite element characteristics, single crystal plasticity model features and the number of grains in the sheet thickness are investigated in order to highlight relevant and influential parameters in CPFEM based microforming process simulations. The influence of the elastic properties is analyzed and a modification of the Peirce-Asaro-Needleman single crystal hardening law is taken into account in order to improve the description of reverse strain path changes. Finally, the numerical results are discussed and compared to the springback measured during the industrial process of the cylindrical connector. It is demonstrated, through the very good agreement with the experimental results, that such approach can be useful to simulate industrial processes.