Identification of hardening parameters using FEMU and DIC-levelled FEA data
Creators: name: Henriques, João
name: Conde, Mariana
name: Andrade-Campos, António
name: Xavier, José
Publisher: name: Zenodo
Year: 2022

description: Computer-aided engineering systems play a key role in the simulation of manufacturing processes, to reduce costs and time waste in the development of high[1]quality products. The material constitutive model and its parameters influence the reliability and accuracy of metal forming simulations. Although finite element analysis (FEA) is widely used to simulate processes, the accuracy of the simulation highly depends on the calibration of the model that describes the material behaviour. Classical approaches use simplified geometry and loading conditions, however, only a limited number of parameters can be identified per test configuration. There has been an increase in the use of novel optical, which are contact-free and provide full-field data, such as digital image correlation (DIC) [1]. This full-field measurement data when coupled with inverse identification techniques such as the finite element method updating technique (FEMU) has the potential to reduce the number of experimental tests required to accurately identify all material properties, assuming that the test configuration is rich enough that all material properties play a role in mechanical behaviour. Classically, experimental DIC measurements and FEA results were compared directly in the FEMU approach. However, numerous inconsistencies must be addressed before doing this comparison, including different coordinate systems, data locations, strain formulation, spatial resolutions, and data filtering. To address these issues, recent studies used an approach based on deforming the reference image of a DIC speckle pattern synthetically, using the FEA mesh and displacements [2,3,4]. This work aims to identify the Swift hardening law parameters of a DP600 steel using a virtual tensile test on a dogbone specimen with a non-constant section under uniaxial and quasi-static loading conditions using the FEMU technique. To simulate a real experiment, the numerical results were used to generate synthetic images, which were then processed by DIC and used as the reference in the identification procedure. Two identification approaches are used: first, by using the direct comparison between the DIC measurements and FEA results, and second, a comparison using DIC-leveled FEA data. The identification results of both approaches are compared.
description: J. Henriques is grateful to the FCT for the PhD grant 2021.05692.BD. This project has received funding from the Research Fund for Coal and Steel under grant agreement No 888153. The authors also gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under the projects CENTRO-01-0145-FEDER-029713, POCI-01-0145 FEDER[1]031243 and POCI-01-0145-FEDER-030592 by UE/FEDER through the programs CENTRO 2020 and COMPETE 2020, and UIDB/00481/2020 and UIDP/00481/2020-FCT under CENTRO-01-0145-FEDER-022083. Authors also acknowledge FCT - MCTES for its financial support via the projects UIDB/00667/2020 (UNIDEMI).