Scaling behaviour of strength of 3D-, semi-flexible-, cross-linked fibre network

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:166

Article

Bergstrom, Per¹  Hossain, Shakhawath² 

[1] Mid Sweden Univ, Dept Chem Engn, Holmgatan 10, SE-85170 Sundsvall, Sweden

[2] Uppsala Univ, Dept Pharm, BMC, SE-75123 Uppsala, Sweden

关键词: Network strength;    Uniaxial tension;    Fibre network;    Cellulose;    Polymer;    Discrete element method;   

DOI  :  10.1016/j.ijsolstr.2019.02.003

来源: Elsevier

【 摘 要 】

Anisotropic, semi-flexible, cross-linked, random fibre networks are ubiquitous both in nature and in a wide variety of industrial materials. Modelling mechanical properties of such networks have been done extensively in terms of criticality, mechanical stability, and scaling of network stiffnesses with structural parameters, such as density. However, strength of the network has received much less attention. In this work we have constructed 3D-planar fibre networks where fibres are, more or less, oriented in the inplane direction, and we have investigated the scaling of network strength with density. Instead of modelling fibres as 1D element (e.g., a beam element with stretching, bending and/or shear stiffnesses), we have treated fibres as a 3D-entity by considering the features like twisting stiffness, transverse stiffness, and finite cross-link (or bond) strength in different deformation modes. We have reconfirmed the previous results of elastic modulus in the literature that, with increasing density, the network modulus indeed undergoes a transition from bending-dominated deformation to stretching-dominated with continuously varying scaling exponent. Network strength, on the other hand, scales with density with a constant exponent, i.e., showing no obvious transition phenomena. Using material parameters for wood fibres, we have found that the predicted results for stiffness and strength agree very well with experimental data of fibre networks of varying densities reported in the literature. (C) 2019 Published by Elsevier Ltd.

【 授权许可】

Free