Publications Details

Experimentally Enhanced Computation (ExEC): Traditional Calibration of Anisotropic Yield Functions

Corona, Edmundo C.; Kramer, Sharlotte L.

This memo addresses the calibration of anisotropic yield functions based on data obtained from a series of uniaxial tension specimens extracted from a tubular Al 7079 circular cylindrical extrusion. Achieving the calibrations completed an important step in the Experimentally Enhanced Computations (ExEC) project. The focus of the project is on novel calibration approaches that will be based on advanced diagnostics and numerical simulations with the intention of reducing the overall calibration effort. The test data used here resulted from traditional tensile tests on specimens cut at 12 orientations within the extrusion. Two anisotropic yield surfaces — Hill’s (1948) and Barlat’s (2005) — were calibrated based on the test data. The methods used to conduct the calibrations are described, and the results show that the material exhibited significant yield anisotropy. The larger number of parameters in Barlat’s yield function allowed it to fit the test data more accurately than Hill’s. Although work remains to assess the sensitivity of the calibrated model parameters to various factors, the methods implemented and the results obtained here provide bases for further work and useful benchmarks for future calibrations to be conducted using the novel approach.