A Brief Note on the Nix-Gao Strain Gradient Plasticity Theory

作者：Borokinni, A. S.; Liu, Dabiao^*

来源：Metals, 2018, 8(9): 708.

DOI：10.3390/met8090708

• strain gradient plasticity
• principle of virtual power
• defect energy
• flow rule
• material length scale

The mathematical nature of the flow rule for the strain gradient plasticity theory proposed by Nix and Gao (W.D. Nix and H. Gao, J Mech Phys Solids 46(3), 411(1998)) is discussed based on the paradigm developed by Gurtin and Anand (M.E. Gurtin and L. Anand, J Mech Phys Solids 57 (3), 405 (2009)). It is shown that, when investigated on the basis of Gurtin-Anand theory, the Nix-Gao flow rule is a combination of constitutive equations for microstresses, balance law, and a constraint. As an accessory, we demonstrate that the strain gradient term introduced in the model is energetic. The results are obtained by combining a virtual-power principle of Fleck and Hutchinson, and the free-energy imbalance under isothermal conditions.

• 出版日期2018-9
• 单位华中科技大学; 西南交通大学