Material model for modeling clay at high strain rates

Buchely, Mario F.; Maranon, A.; Silberschmidt, Vadim V.

doi:10.1016/j.ijimpeng.2015.11.005

“…The density of the pure plasticine was set to be 1868 kg/m 3 by experimental measurement. The Young's modulus was calculated to be 2.6 MPa based on the stress/strain curves, while the Poisson's ratio was set to be 0.4 by averaging the data in the literature [35,44,45]. The Coulomb friction model was applied to describe the friction behaviours between the soft plasticine and the rigid dies.…”

Section: Finite Element Modelmentioning

confidence: 99%

Investigation and prediction of central cracking in cross wedge rolling

Zhou

¹

,

Sun

²

,

Wang

³

et al. 2022

Int J Adv Manuf Technol

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Central cracking refers to the formation of internal cavities in cross wedge rolling (CWR) products. It occurs in various materials such as aluminium/titanium alloys, steels and plasticine at room or elevated temperatures, driven by different central cracking mechanisms. However, these mechanisms are still elusive, and a unified central cracking predictive model is absent due to the complex stress states within the workpiece, including triaxial stress states, cyclic loading and severe shear effects. In this study, the underlying fracture mechanisms were revealed, and a robust unified damage model with sound physical meanings was developed using a lab-scale CWR physical model and finite element models. The physical model with the plasticine billets was built, allowing the CWR dies with different geometries rapidly 3D printed and the billets with various ductility efficiently manufactured. The central cracking transiting from brittle to ductile fracture was experimentally observed for the first time using specifically designed plasticine/flour composite samples at varying ductility. The corresponding physics-based central cracking predictive model was proposed and validated quantitatively with 60 groups of CWR tests and compared with ten existing damage models/fracture criteria. This study effectively solves the long-lasting central cracking problem in the CWR industry and enhances the scientific understanding of fracture mechanics in complex engineering applications.

show abstract

“…The density of the pure plasticine was set to be 1868 kg/m 3 by experimental measurement. The Young's modulus was calculated to be 2.6 MPa based on the stress/strain curves, while the Poisson's ratio was set to be 0.4 by averaging the data in the literature [33,41,42].…”

Section: Finite Element Modelmentioning

confidence: 99%

Investigation and prediction of central cracking in cross wedge rolling

Zhou¹,

Sun²,

Wang³

et al. 2022

Preprint

0

View full text Add to dashboard Cite

Central cracking refers to the formation of internal cavities in cross wedge rolling (CWR) products. It occurs in various materials such as aluminium/titanium alloys, steels and plasticine at room or elevated temperatures, driven by different central cracking mechanisms. However, these mechanisms are still elusive, and a unified central cracking predictive model is absent due to the complex stress states within the workpiece, including triaxial stress states, cyclic loading and severe shear effects. In this study, the underlying fracture mechanisms were revealed, and a robust unified damage model with sound physical meanings was developed using a lab-scale CWR physical model and finite element models. The physical model with the plasticine billets was built, allowing the CWR dies with different geometries rapidly 3D printed and the billets with various ductility efficiently manufactured. The central cracking transiting from brittle to ductile fracture was experimentally observed for the first time using specifically designed plasticine/flour composite samples at varying ductility. The corresponding physics-based central cracking predictive model was proposed and validated quantitatively with 60 groups of CWR tests and compared with ten existing damage models/fracture criteria. This study effectively solves the long-lasting central cracking problem in the CWR industry and enhances the scientific understanding of fracture mechanics in complex engineering applications.

show abstract

“…The density of the material was calculated by the measured weight and volume of the manufactured samples. The Young's modulus was calculated from the stress/strain curves, while the value of the Poisson's ratio was averaged from data in previous investigations of plasticine materials in the literature [41,42].…”

Section: Cross Wedge Rolling Finite Element Modelmentioning

confidence: 99%