Modelling the compression of three-dimensional fibre networks using dynamic finite-element analysis

A numerical approach was developed to study the transverse compressibility of a three-dimensional fibre network, representing paper, tinder dynamic compression and to examine the relationship between this mechanical property and fibre characteristics using the commercial sofhware ANSYS/LSDYNA. A nonlinear stress-strain relationship was obtained for the compression of the fibre network in the thickness direction. These results were comparable to those achieved experimentally for kraft handsheets using a high-speed micro-compression analyzer. The degree of compression greatly affected the permanent strain of the network. Furthermore, the change in surface roughness of this network due to compression was found to be proportional to the change it? bulk of the network, regardless of the fibre mechanical properties. However, the proportionality constant between the change in roughness and bulk was found to be affected by fibre morphology: for the same degree of change in bulk, coarser fibres led to a greater change in network roughness upon compression.