An evolving non-associated Hill48 plasticity model accounting for anisotropic hardening and r-value evolution and its application to forming limit prediction

Lian, Junhe; Shen, Fuhui; Jia, Xiaoyun; Ahn, Deok-Chan; Chae, Dongho; Münstermann, Sebastian; Bleck, Wolfgang

doi:10.1016/j.ijsolstr.2017.04.007

Cited by 91 publications

(40 citation statements)

References 46 publications

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“…The corresponding parameters are presented in Table 3. The two sets are different due to the limitations of the model and its inability to describe different degrees of anisotropy of the yield stress and deformation at the same time [60]. Importantly, the two sets differ only by the magnitude of σ Fig.…”

Section: Dogbone Testingmentioning

confidence: 99%

Experimental Validation of the Sensitivity-Based Virtual Fields for Identification of Anisotropic Plasticity Models

et al. 2020

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In this work, the sensitivity-based virtual fields have been applied to identify two anisotropic plasticity models (Hill48, Yld2000-2D) using a deep-notched tensile test performed on flat samples of cold-rolled sheet of DC04 steel. The material was characterised using the standard protocol to obtain the reference sets of parameters. Deformation data was obtained during deep-notched tests using stereo digital image correlation and the virtual fields method was employed to identify material parameters. It was found that the sensitivity-based virtual fields outperform the standard user-defined virtual fields in terms of accuracy.

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Section: Dogbone Testingmentioning

confidence: 99%

Experimental Validation of the Sensitivity-Based Virtual Fields for Identification of Anisotropic Plasticity Models

et al. 2020

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“…Uniaxial tension in the RD is used as the reference hardening curve. Then, the normalized flow stresses with respect to the reference one, i.e.,

, are calculated at the plastic work of

= 10 MJ/m 3 (equivalent to

= 0.13) based on the work equivalence, i.e.,

[ 10 ]. The value of 10 MJ/m 3 is chosen so that these normalized values become saturated with respect to further increase of the plastic work (see Appendix A ).…”

Section: Plastic Anisotropymentioning

confidence: 99%

“…Swift [ 6 ] associated the occurrence of diffuse necking with the maximum load so that it could be applicable for the right hand quadrant of the FLD. Hora et al [ 7 , 8 ] later developed the Modified Maximum Force Criterion (MMFC) on the basis of a zero extension [ 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Plasticity and Formability of Annealed, Commercially-Pure Aluminum: Experiments and Modeling

Fones

Kinsey

et al. 2020

Materials

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The plasticity and formability of a commercially-pure aluminum sheet (AA1100-O) is assessed by experiments and analyses. Plastic anisotropy of this material is characterized by uniaxial and plane-strain tension along with disk compression experiments, and is found to be non-negligible (e.g., the r-values vary between 0.445 and 1.18). On the other hand, the strain-rate sensitivity of the material is negligible at quasistatic rates. These results are used to calibrate constitutive models, i.e., the Yld2000-2d anisotropic yield criterion as the plastic potential and the Voce isotropic hardening law. Marciniak-type experiments on a fully-instrumented hydraulic press are performed to determine the Forming Limit Curve of this material. Stereo-type Digital Image Correlation is used, which confirms the proportional strain paths induced during stretching. From these experiments, limit strains, i.e., the onset of necking, are determined by the method proposed by ISO, as well as two methods based on the second derivative. To identify the exact instant of necking, a criterion based on a statistical analysis of the noise that the strain signals have during uniform deformation versus the systematic deviations that necking induces is proposed. Finite element simulation for the Marciniak-type experiment is conducted and the results show good agreement with the experiment.

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“…They showed that the model could successfully predict the evolution of r-values and yield stresses during plastic deformation. Lian et al [14] proposed non-associated Hill48 plasticity model depend on the anisotropy evolution and used this model to predict forming limit diagram (FLD) of ferritic stainless steel. They successfully validated the model with experimental results.…”

Section: Introductionmentioning

confidence: 99%

Modeling plastic anisotropy evolution of AISI 304 steel sheets by a polynomial yield function

2021

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In this study, a numerical model for the evolution of plastic anisotropy is investigated for the purpose of stamping method design by Finite Element (FE) analysis and proved experimentally via process simulations of a cold-rolled austenitic stainless steel (AISI 304) sheet. The plastic anisotropy of the sheets is described with a fourth-order homogenous polynomial yield function and this modelling approach is enhanced by plastic strain dependent material coefficients. Tensile tests of coupon specimens taken along the different directions from rolling direction, and flow strength and deformation anisotropies are described with the planar variations of yield stress and plastic strain ratio computed at four plastic strain levels (0.002, 0.02, 0.05 and 0.18). A new numerical approach is, then, applied to identify polynomial coefficients ensuring an orthotropic positive-definite, convex yield surface with a well-defined stress gradient at every loading point on plane stress subspace. The developed computational model is implemented into general purpose explicit FE analysis software Ls-Dyna by a user-defined material model subroutine (UMAT) and applied in the stamping simulation of AISI 304 steel rectangular cups for the house-hold applications. The computed thickness distributions and the flange geometries were compared with measurements and it was observed that the best predictions were done with material parameters at %5 plastic strain level.

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An evolving non-associated Hill48 plasticity model accounting for anisotropic hardening and r-value evolution and its application to forming limit prediction

Cited by 91 publications

References 46 publications

Experimental Validation of the Sensitivity-Based Virtual Fields for Identification of Anisotropic Plasticity Models

Experimental Validation of the Sensitivity-Based Virtual Fields for Identification of Anisotropic Plasticity Models

Plasticity and Formability of Annealed, Commercially-Pure Aluminum: Experiments and Modeling

Modeling plastic anisotropy evolution of AISI 304 steel sheets by a polynomial yield function

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