چكيده به لاتين
Sheet metal forming simulation is an intense research area due to the sheet material evolutions imposed by environmental constraints. Among other ingredients, material behavior description is continuously enriched by new advanced models. Such models require significant skills and efforts to be implemented and characterized. There is a lack of experimental validation means to assess the effective improvements potentially brought by such advanced models.
This project aimed to develop specific sheet metal forming benchmark experiments. The objective of these experiments was to serve for discriminant material model validation. Indeed, when the influence of an advanced material model on the results of a forming experiment was similar to the measurement error, the experiment could not serve for model assessment. As an additional constraint, the experimental results should be relevant for industrial application. Consequently, geometrical measurements like Springback, draw-in or force evolution preferred. In the other words, the main task in this project was to do simulations of the Springback and Biaxial Pre-deformation of steel sheet in Stamping with different models of Hardening.
Two experimental devices are specifically studied. One experiment allows for relatively small holding forces to promote draw-in. Typically, Springback including cross-sectional Springback. The second experiment allows for uniform pre-straining of large samples in biaxial and/or uniaxial tension, in view of subsequent sample cutting and testing under different loading modes. We were using numerical simulation in order to optimize the sample and tooling geometries to maximize the sensitivity of the experimental results to the material model. In this respect, two extreme hardening models were compared (pure Isotropic and pure Kinematic). Once the optimum geometries and parameters were determined, the experimental devices have been designed in view of their installation on the 600-ton hydraulic press at ENSAM Metz.
