Fig. 18.

a The schematic above gives an explanation for the increase we find in the plateau stress when the samples are compressed in the x and y-directions. The response originates from columnar buckling [20] of the fibre layers in the xy planes. The higher number of support fibres/bundles between the layers increases the critical buckling force and shortens the plateau region as there is less open space between the layers. b The Plateau stress varies linearly with the orientation factor $P(80-90)/P(0-10)$, which is a measure of the number of fibres aligned towards the z-direction (see Fig. 13c, and which is controlled via the initial liquid fraction ${\varphi }_i$ of the precursor fibre-foam dispersion