Comparing two different approaches to the identification of the plastic parameters of metals in post-necking regime

BALDI, ANTONIO;MEDDA, ANDREA;BERTOLINO, FILIPPO

2010-01-01

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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.