Flow Behavior of Automotive Aluminum Sheets During In-Plane Uniaxial and Biaxial Compression Loading

Zillmann, B.; Härtel, M.; Halle, T.; Lampke, T.; Wagner, M.F.-X.

Flow Behavior of Automotive Aluminum Sheets During In-Plane Uniaxial and Biaxial Compression Loading (bibtex)

by B. Zillmann, M. Härtel, T. Halle, T. Lampke, M.F.-X. Wagner

Abstract:

The most widely used yield criteria that describe the initial yield surface are based on the assumption of tension-compression symmetry. A couple testing techniques exist that document the anisotropic material behavior under biaxial, tensile loading, and the corresponding data are already included in several yield criteria for sheet metal forming simulations. But, because of a lack of experimental data, biaxial compressive load cases are typically not considered in these models. In this paper, we study the flow behavior of textured automotive aluminum sheets in a wide range of biaxial, compressive stress states, using a newly designed test rig. The initial flow behavior during uniaxial and biaxial compression loading is investigated for two aluminum alloys and compared to uniaxial tensile flow stresses and also to data from equi-biaxial tensile testing. A distinct tension-compression asymmetry is observed for an AA5182 alloy at low plastic strains; no significant differences in tension and compression loading can be measured on an AA6016 alloy. The experimental data are complemented by the results of shear tests, so that yield stresses from all quadrants can be used to determine the initial yield surface. Our results demonstrate how important the consideration of the third quadrant (i.e., biaxial compression) is for a more accurate description of yield surfaces.

Reference:

Zillmann, B., Härtel, M., Halle, T., Lampke, T., Wagner, M.F.-X.: Flow Behavior of Automotive Aluminum Sheets During In-Plane Uniaxial and Biaxial Compression Loading, Proc. of the 10th International Conference on Technology of Plasticity, 691-695, 2011.

Bibtex Entry:

@Article{Zillmann2011a,
  Title                    = {{Flow Behavior of Automotive Aluminum Sheets During In-Plane Uniaxial and Biaxial Compression Loading}},
  Author                   = {Zillmann, B. and H\"{a}rtel, M. and Halle, T. and Lampke, T. and Wagner, M.F.-X.},
  Journal                  = {Proc. of the 10th International Conference on Technology of Plasticity},
  Year                     = {2011},
  Pages                    = {691--695},

  Abstract                 = {The most widely used yield criteria that describe the initial yield surface are based on the assumption of tension-compression symmetry. A couple testing techniques exist that document the anisotropic material behavior under biaxial, tensile loading, and the corresponding data are already included in several yield criteria for sheet metal forming simulations. But, because of a lack of experimental data, biaxial compressive load cases are typically not considered in these models. In this paper, we study the flow behavior of textured automotive aluminum sheets in a wide range of biaxial, compressive stress states, using a newly designed test rig. The initial flow behavior during uniaxial and biaxial compression loading is investigated for two aluminum alloys and compared to uniaxial tensile flow stresses and also to data from equi-biaxial tensile testing. A distinct tension-compression asymmetry is observed for an AA5182 alloy at low plastic strains; no significant differences in tension and compression loading can be measured on an AA6016 alloy. The experimental data are complemented by the results of shear tests, so that yield stresses from all quadrants can be used to determine the initial yield surface. Our results demonstrate how important the consideration of the third quadrant (i.e., biaxial compression) is for a more accurate description of yield surfaces.},
  Address                  = {Aachen},
  Editor                   = {Hirt, G and Tekkaya, A E},
  ISBN                     = {978-3-514-00784-0},
  ISSN                     = {1611-3683}
}