Experimental verification results of real and equivalent drawbeads numerical simulations

Zbigniew Zimniak, Dawid Rutkowski

Institute of Production Engineering and Automation, Wroclaw University of Technology,ul. Łukasiewicza 5, 50-371 Wroclaw, Poland.

DOI:

https://doi.org/10.7494/cmms.2010.1.0277

Abstract:

In sheet metal forming, drawbeads play an important role in material flow control. In this paper the results of simulations of drawbeads and equivalent drawbeads are experimentally verified. Strain and thickness variations were measured for a rectangular drawpiece. FEM modelling was done with commercial software LS-DYNA using explicit and implicit FEA codes. Three-dimensional numerical simulations were run using Hill’s 1948 anisotropic yield function and the Barlat-Lian (1989) constitutive model. Calculations relating to the gravitational force loading and the drawing process were done using the explicit method and the spring back simulation was carried out using the implicit method. The numerical simulation results were verified through the measurement of principal strains in selected cross sections of the drawpiece. As regards the principal strain distributions and the final drawpiece dimensions, good agreement between the experimental measurements and the FEM calculations was obtained. The best agreement for real drawbeads results occurred under the Barlat-Lian criterion. In the model an equivalent drawbead is represented by a line on the surface of the tools, along which the prescribed drawbead restraint force (DBRF) were exerted. This means that calculating the drawbead restrain force from formula and describing the sheet material by means of the Barlat-Lian criterion one can successfully use equivalent drawbeads.

Cite as:

Zimniak, Z., & Rutkowski, D. (2010). Experimental verification results of real and equivalent drawbeads numerical simulations. Computer Methods in Materials Science, 10(1), 52 – 57. https://doi.org/10.7494/cmms.2010.1.0277

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