An explanation of damage and failure in cellulose aerogels: modeling approach

Abstract

AbstractCellulose aerogels can be considered as foam‐like materials and have recently been modeled using micro‐mechanical approaches. The proposed microcell based models describe the constitutive response of these aerogels based primarily on the bending of the cell wall fibrils, and show good agreement with experimental data. Under compression, the cell walls are considered to undergo nonlinear bending. On the other hand, under tension the deformation in the cell walls is attributed to both, bending and stretching. Accordingly, the total aerogel network energy is divided into a bending one and a tension one. The cell walls undergoing such combined loading fail after reaching a critical normal stress value, and are then considered to no longer contribute to the total network energy. Material constants in these models are obtained from experimental observations, like for example, the pore‐size data analysis, thus resulting into physically motivated models. Finally, the models are also shown to be effective in predicting the constitutive response of other polysaccharidic aerogels. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)