Professor Vadim V. Silberschmidt, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University

Fibrous Networks: Deformation and Damage
When Mar 10, 2014
from 02:00 PM to 03:00 PM
Where LR8, IEB Building, Engineering Science
Contact Name
Contact Phone 01865-283302
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A mechanical behaviour of random fibrous networks is predominantly governed by their discontinuous and non-uniform microstructure. This study examines the effect of microstructure on macroscopic deformation and failure behaviour of random fibrous networks – a low-density thermally bonded non-woven material being used as an example – using a combination of experimental studies, microstructural analysis and advanced finite-element simulations. The network’s microstructure was characterised in terms of orientation distribution function obtained based on SEM and microCT images. The mechanical tests were performed at two levels – for single fibres and fabric samples. Single-fibre properties were obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that bond points were attached at both ends of each fibre to account for the effect of manufacturing process.

A parametric finite-element modelling approach – a tool to develop and characterise random fibrous networks – is also presented. It was used to incorporate microstructure of the network into the model by direct introduction of fibres (and their individual mechanical properties) according to their orientation distribution in the fabric together with a specific pattern of bond points. The model reproduced main deformation and damage mechanisms experimentally observed and provided the meso- and macro-level responses of the fabric. The suggested microstructure-based approach identified and quantified a spread of stresses and strains in fibres of the network for different levels of stretching as well as its structural evolution during deformation and damage. The simulations also predicted changes in distributions of stresses and strains due to structural evolution and progressive failure of fibres.