Plastic microstress for a defect energy dependent on Burgers tensor

• Autorzy: Borokinni Adebowale S.

Identyfikatory

DOI

10.15632/jtam-pl/104596

• Języki publikacji: EN

Abstrakty

EN

This work presents an extended form of the Aifantis strain-gradient plasticity theory through dependence of the plastic free energy on the Burgers tensor. The constraints of codirectionality for the deviatoric stress and irrotationality of the plastic distortion are assumed. These provide the basis for expressing the work done by the microstress conjugate to the Burgers tensor as the sum of the work done by the microscopic hyperstress vector and scalar. The principle of virtual power is used to establish the microforce balance, which provides the relationship between the resolved shears, plastic microstress and the microscopic hyperstresses. The microforce balance, when augmented with relevant constitutive relations that are consistent with the free-energy imbalance, results in a non-local flow rule depicted as a nonlinear second order partial differential equation in terms of the accumulated plastic strain with concomitant boundary conditions. It is shown in this work that the plastic microstress is purely dissipative and cannot account for backstress whenever the defect energy is dependent on the Burgers tensor.

Słowa kluczowe

EN

Burgers tensor; codirectionality hypothesis; strain-gradient plasticity; isotropic body; polycrystalline solid

• Wydawca: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
• Czasopismo: Journal of Theoretical and Applied Mechanics
• Rocznik: 2019
• Tom: Vol. 57 nr 2
• Strony: 343--351
• Opis fizyczny: Bibliogr. 13 poz.

Twórcy

autor

Borokinni Adebowale S.

• Mathematics Unit, Distance Learning Institute, University of Lagos, Akoka, Nigeria

Bibliografia

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• 10. Mualhaus H.B., Aifantis E.C., 1991, A variational principle for gradient plasticity, International Journal of Solids and Structures, 28, 845-857
• 11. Poh L.H., Peerlings R.H.J., 2016, The plastic rotation effect in an isotropic gradient plasticity model for applications at the meso scale, International Journal of Solids and Structures, 78-79, 75-69
• 12. Stelmashenko N.A., Wallis M.G., Brown L.M., Milman Y.V., 1993. Microidentations on W and Mo oriented single crystals: An STM study, Acta Metallurgica et Materialia, 41, 2855-2865
• 13. Stolken J.S., Evans A.G., 1998, A microbend test method for measuring the plasticity length scale, Acta Materialia, 46, 5109-5115

Uwagi

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).