Damage development around moulded-in holes in flat braided composites (CD-ROM)

Textile techniques like overbraiding offer the possibility to perform some function integration during the composite fabrication stage. As an example, it is possible to integrate axes or holes necessary to transfer loads to the composite structure. Moreover, this prevents drilling and therefore fracturing load-carrying fibres at a latter stage. However, this means a local reorientation of the fibre and therefore a change in properties. This paper proposes a model for the reorientation of the fibres around a moulded-in hole. A subsequent finite element analysis shows the influence of this reorientation on the stress situation around the hole. Validation on pressed glass-PPS specimens loaded under tension shows that the proposed model is able to predict damage initiation in the vicinity of the hole.