Experimental determination of the Hosford yield function exponential parameter for metal plates

Abstract

The Hosford yield function can be used to describe both the plastic yield and plastic deformation of metal plates very well when the value of its exponential parameter $$\eta$$ is known. The values of $$\eta$$ for BCC and FCC metals have been determined to be 6 and 8, respectively, based on the Taylor crystal plasticity model. However, an effective experimental method has not been developed to determine the value of $$\eta$$ for metal plates. This work addresses the above issue by developing an experimental method for determining the value of $$\eta$$ for metal plates based on a theoretical model. Deep drawing experiments are conducted with 0.8 mm thick 5052 aluminum alloy plates, and the experimental value of $$\eta$$ is determined according to the theoretical model based on the experimentally measured thickness anisotropy coefficient, the known drawing coefficient, and the radial elongation ratio of the drawing cup obtained during the deep drawing experiments. The experiments yield an $$\eta$$ value of 8.02 for the aluminum alloy plates. The experimental value is verified by applying it within deep drawing simulations using Dynaform software based on the finite element method. The simulated cup height is in good agreement with the experimentally derived cup height. The value of $$\eta$$ can be determined for metal plates through deep drawing experiments based on the proposed methodology.