Identification and validation of Brass material parameters using single point incremental forming

The identification of material parameters of a Brass alloy using single point incremental forming (SPIF) is presented. The determination of accurate law parameters for metal sheets in the whole range of their plastic deformation field is a challenge in order to reach efficient forming simulations of manufacturing processes. The identification is performed using a home-made optimization code based on Levenberg-Marquardt algorithm.
To validate the previously identified material data, an identifiability method is developed. This method consists in measuring the influence of a material parameter on the SPIF test by analyzing the sensitivity matrix. Such information permits to assess the capacity of a SPIF test to be used to identify the material parameters. A consisting scalar (the identifiability index), concluded from the highest and the lowest eigenvalues of the Fisher’s matrix, gives an indication about the most appropriate SPIF tests to identify the material data.