Comparing Two Different Approaches to the Identification of the Plastic Parameters of Metals in Post-necking Regime

Abstract

In the past 20 years the growing computation power availability encouraged experimental mechanics specialists to couple full field measurements with FE methods to raise the so called hybrid experimental-numerical methods. A typical example is the identification of the plastic parameters of metals starting from experimental data.

In this work a comparison of two different inverse approaches is presented. A global method, called Kali, identifies the parameters of a plastic law (e.g. Ramberg-Osgood, Hollomon,...) fitting the global experimental data (load, clip-gauge) with FE results obtained using the trial parameters. Instead a full field method, called PlastFemDIC, prescribes DIC measured displacement data of the specimen surface as well as the global ones.

To judge the best approach, the silhouette of a round axial-symmetric specimen is compared at various load levels with the FEM results obtained with the parameters identified by the global and local approaches.