Analyses of interaction mechanisms during forming of multilayer carbon woven fabrics for composite applications

The use of textile reinforcing structures provides enormous possibilities in the design of lightweight composites. However, the physical mechanisms during fabric forming are complex and far from being fully understood especially in multilayer draping. The aims of this study are the analyses of interaction mechanisms of individual textile layers during the forming operation and of defects arising from interactions. In basic experiments of the carbon woven fabric, friction properties and the fabric integrity were investigated. In single and multilayer draping experiments the findings were transferred to the composite preforming process. Interaction defects are characterised as interdependency between the acting inter-ply shear forces and the structural integrity of the fabric. The defects resulting from the interactions depend on the configuration of the fabric (e. g. shearing) and the acting normal forces. The reduction of friction is crucial for the preform quality but is opposite to an actively force-controlled material manipulation.