Mechanical performance of through-thickness tufted sandwich structures

This paper presents a study about the influence of through-thickness tufted fibres on compression and bending properties of sandwich structures. The tufting process aims to avoid the delamination between the skin and core in order to improve the performance of sandwich structures, increase the interlaminar strength and damage tolerance of sandwich structures. To evaluate the effect of tufting in sandwich structures, an experimental study was developed which included edgewise compression and 3P bending tests of tufted and non-tufted sandwich panels made of carbon/epoxy and E-glass/epoxy face-sheets, PVC and polyurethane foam cores and E-glass through-thickness fibres with different tufting densities. A finite element model was formulated to evaluate the effects of tufting spacing on the sandwich performance under three-point bending. Conclusions about the efficiency of the insertion of through-thickness fibres on compression and bending properties are drawn.