A MIXED FINITE ELEMENT FORMULATION OF TRIPHASIC MECHANO-ELECTROCHEMICAL THEORY FOR CHARGED, HYDRATED BIOLOGICAL SOFT TISSUES

摘要: An equivalent new expression of the triphasic mechano-electrochemical theory [9] is presented and a mixed finite element formulation developed using standard Galerkin weighted residual method. Solid displacement us, modified electrochemical/chemical potentials ϵw, ϵ+and ϵ− (with dimensions concentration) for water, cation anion are chosen as four primary degrees freedom (DOFs) independently interpolated. The Newton–Raphson iterative procedure employed to handle non-linear terms. resulting first-order Ordinary Differential Equations (ODEs) with respect time solved implicit Euler backward scheme which unconditionally stable. One-dimensional (1-D) linear isoparametric developed. final algebraic equations form non-symmetric but sparse matrix system. With current choice DOFs, has advantage small amount storage, jump conditions between elements across interface boundary satisfied automatically. been used investigate 1-D stress relaxation problem in confined compression configuration free swelling problem. accuracy convergence cases examined independent difference methods. FEM results excellent agreement those obtained from other Copyright © 1999 John Wiley & Sons, Ltd.