文献类型：期刊文献

英文题名：Fifth-degree elastic potential for predictive stress-strain relations and elastic instabilities under large strain and complex loading in Si

作者：Chen, Hao[1,2]; Zarkevich, Nikolai A.[3]; Levitas, Valery I.[2,3,4]; Johnson, Duane D.[3,5]; Zhang, Xiancheng[1]

机构：[1] Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] Department of Aerospace Engineering, Iowa State University, Ames, IA, 50011, United States; [3] Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, IA, 50011-3020, United States; [4] Department of Mechanical Engineering, Iowa State University, Ames, IA, 50011, United States; [5] Department of Materials Science & Engineering, Iowa State University, Ames, IA, 50011, United States

年份：2020

外文期刊名：arXiv

收录：EI(收录号：20200247516)

语种：英文

外文关键词：Lagrange multipliers - Loading - Silicon compounds - Strain - Stress-strain curves - Twinning

摘要：Materials under complex loading develop large strains and often transition via an elastic instability, as observed in both simple and complex systems. Here, we represent Si I under large strain in terms of Lagrangian strains by an 5th-order elastic potential found by minimizing error relative to density functional theory (DFT) results. The Cauchy stress - Lagrangian strain curves for arbitrary complex loadings are in excellent correspondence with DFT results, including the elastic instability driving the Si I→II phase transformation (PT) and the shear instabilities. PT conditions for Si I→II under action of cubic axial stresses are linear in Cauchy stresses in agreement with DFT predictions. Such elastic potential permits study of elastic instabilities and orientational dependence leading to different PTs, slip, twinning, or fracture, providing a fundamental basis for continuum simulations of crystal behavior under extreme loading. Copyright ? 2020, The Authors. All rights reserved.