Simulation and Experimental Studies of the Draping Behaviour of NCF on a Double-Curved Mould

Kurzfassung

The high drapability of dry textile fabrics being used together with resin infusion processes is both a major advantage and a major challenge for the quality and mechanical performance of a FRP-structure. In this paper the draping of a Non Crimped Fabric (NCF) over the surface of a double-curved structure and the infiltration using the VARI-Process will be presented. The draping process mainly benefits from a high shear deformation of the NCF, which may lead to wrinkles in the fabric, once certain limits have been exceeded. Furthermore, the fiber orientation between the single layers inside the NCF is affected and as a consequence of that the outer contour of the fabric changes. At the joints between two fabrics a discontinuity of the fiber orientation occurs, which is an important input for calculating the mechanical stresses. A commercial software was used to calculate the contours of the cut-outs and the fiber orientations in several plies to ensure an exact fit. The presentation will describe the experience gained and the conclusions drawn out of this study. This includes a study showing the differences between the calculated results and the occurring fiber lay-up.