An innovative procedure for characterising a coupled elastoplastic damage model of behaviour using the Virtual Fields Method

Numerical simulations have become essential in engineering and manufacturing processes involving plasticity. The reliability and effectiveness of the simulations depend strongly on the accuracy of the adopted constitutive model. Accordingly, in recent years, an increasing interest is pointed towards experimental procedures and characterization methods that can be used to identify the constitutive parameters of advanced plasticity models, which allow to simulate properly the plastic behaviour of complex materials like, for instance, high strength steel. This paper provides a thorough review of the current stateof-the-art, looking at both academia and industry. The available methodologies can be subdivided in two main areas: quasi-homogeneous material tests with analytical or numerical post-treatment of the experimental data and heterogeneous tests coupled with inverse methods for parameter identification. For each method, a brief description and references to norms and articles is provided, illustrating the advantages and the disadvantages.

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“…The virtual displacement fields must be chosen in order to be constant along the boundary

{normalΓ}_{f}

and collinear with

\overset{boldf}{true}

to eliminate the components of the resultant force that are unknown. [ 128,135 ] Apart from that, the virtual fields must have to assure a

C^{0}

continuity.…”

Section: Heterogeneous Tests Coupled With Inverse Methodsmentioning

confidence: 99%

Testing methodologies for the calibration of advanced plasticity models for sheet metals: A review

Rossi

Lattanzi

Morichelli

et al. 2022

Strain

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“…In the general case, the identification of non-linear material constitutive models with the VFM relies on the minimization of a cost function, Φ, describing a distance to equilibrium based on the PVW (Eqn. 2) [7,[29][30][31]. This cost function Φ may be defined by Eqn.…”

Section: The Virtual Fields Methods (Vfm)mentioning

confidence: 99%

A computational approach to design new tests for viscoplasticity characterization at high strain-rates

et al. 2019

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Rate-dependent behaviour characterization of metals at high strain rate remains challenging mainly because of the strong hypotheses when tests are processed with statically determinate approaches. As a non-standard methodology, Image-Based Inertial Impact (IBII) test has been proposed to take advantage of the dynamic Virtual Fields Method (VFM) which enables the identification of constitutive parameters with strain and acceleration fields. However, most of the test parameters (e.g. projectile velocity, specimen geometry) are not constrained. Therefore, an FE-based approach is addressed to optimize the identification over a wide range of strain and strain-rate, according to two design criteria: (1)-the characterized viscoplastic spectra (2)-the identifiability of the parameters. Whereas the first criterion is assessed by processing the FEA simulations, the second is rated extracting material parameters using synthetic images to input the VFM. Finally, uncertainties regarding the identification of material constants are quantified for each IBII test configuration and different camera performances.

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“…In the general case, the identification of non-linear material constitutive models with the VFM relies on the minimisation of a cost function, Φ, describing a distance to equilibrium based on the PVW (Eqn. 1) [9,[18][19][20]. This cost function Φ may be defined by Eqn.…”

Section: The Virtual Fields Methods (Vfm)mentioning

confidence: 99%

Image-Based Inertial Impact Test for Characterisation of Strain Rate Dependency of Ti6Al4V Titanium Alloy

et al. 2019

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In the present work Image-Based Inertial Impact (IBII) tests are performed on Ti6Al4V material. The IBII test uses an impact on the edge of the specimen to generate a short pulse that loads the specimen. Three specimen geometries have been tested: a classic rectangular specimen, and two specimen geometries with stress concentrating geometries (i.e. a hole and notches) to enhance high levels of plastic strain. Full-field measurement of the acceleration and strain are successfully used in combination with the Virtual Fields Method (VFM) to identify the strain rate sensitivity parameter of the Johnson-Cook model. The strain/strain rate spectra covered by each specimen are analysed. Finally, the influence of the virtual field used in the identification process is discussed as well as the simultaneous identification of the Johnson-Cook model strain rate sensitivity parameter and the strain rate threshold parameter.

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An innovative procedure for characterising a coupled elastoplastic damage model of behaviour using the Virtual Fields Method

Cited by 15 publications

References 36 publications

Testing methodologies for the calibration of advanced plasticity models for sheet metals: A review

Testing methodologies for the calibration of advanced plasticity models for sheet metals: A review

A computational approach to design new tests for viscoplasticity characterization at high strain-rates

Image-Based Inertial Impact Test for Characterisation of Strain Rate Dependency of Ti6Al4V Titanium Alloy

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