|About this Abstract
||NUMIFORM 2019: The 13th International Conference on Numerical Methods in Industrial Forming Processes
||S-01: Modeling of the Anisotropic Behavior in Plasticity
||Modeling of the Differential Hardening of Pure Titanium Sheet and Application to Hole Expansion Forming Simulation
||Chiharu Nagano, Toshihiko Kuwabara, Ryoji Kawamura, Yuta Shimada
|On-Site Speaker (Planned)
Uniaxial and biaxial tensile tests of a JIS #1 pure titanium sheet are performed to determine an accurate material model to be used in sheet metal forming simulations of the material. Uniaxial tensile tests are performed at every 15ᵒ from the rolling direction (RD). Biaxial tensile tests with seven liner stress paths in the first quadrant of a principal stress space are performed using the multiaxial tube expansion testing method developed by Kuwabara and Sugawara (2013). Contours of plastic work (CPW) and the directions of the plastic strain rates are precisely measured at different levels of plastic work. The maximum plastic strain applied to the material under biaxial tension is 0.3. It is observed that the shapes of the CPW significantly change with plastic work; the material shows differential hardening (DH). The Yld2000-2d yield function (Barlat et al., 2003) is applied to reproduce the DH, in which the exponent and material parameters (alpha 1 to 8) of the Yld2000-2d yield function are changed as functions of plastic strain. Furthermore, the DH model is applied to a finite element analysis of a hole expansion forming of the test material. It is found that the DH model can predict the thickness distribution along the RD and the position of the minimum thickness.