Microstructure-dependent nonlinear viscoelasticity due to extracellular flow within cellular structures

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:47

Article

Moravec, F.¹  Holecek, M.^1,2 

[1] Univ W Bohemia, Dept Mech, Plzen 30614, Czech Republic

[2] Univ W Bohemia, New Technol Ctr, Plzen 30614, Czech Republic

关键词: Viscoelasticity;    Cellular structures;    Constitutive laws;    Internal variables;    Dissipation;   

DOI  :  10.1016/j.ijsolstr.2010.03.024

来源: Elsevier

【 摘 要 】

A constitutive model that highlights a special viscoelastic property of materials with cellular microstructures is developed. We model the microstructure as a regularly arranged system of the same elastic cells that are mutually interconnected by elastic linkages. The space between cells is filled by a fluid that may flow freely within this extracellular space. The macroscopic behavior of the whole structure is studied by means of continuum mechanics using a differential scheme with internal variables. Here, the internal variables are chosen as the distances that separate neighboring cells. The evolution equations are derived from the Clausius-Planck inequality, which considers the internal dissipation to be exclusively due to the extracellular fluid movement. Special attention is paid to incompressible materials in the context of uniaxial load. In this context, the importance of the fluid viscosity on material behavior is related to microstructural parameters like the cells' dimensions and the relative stiffness between the cells and matrix elastic reinforcement. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

Free