Abstract
Continuous fiber reinforced thermoplastic laminates, in comparison with monolithic metallic sheets, are effectively inextensible in the direction of their reinforcements and therefore severely limited in the range of possible deformations they can undergo during forming. Inter-ply and intra-ply shearing plays a major role in the determination of the degree of formability of such laminates. The present study focuses on the shear behavior of CFRT sheets in inter-ply and intra-ply modes aiming to assess their significance in matched-die and double diaphragm forming processes. In order to gain a better understanding of the minimum stress levels necessary to induce the two different shear modes, basic shearing experiments on single plies and unidirectional reinforced laminates were conducted prior to forming spherical shaped dome parts. By forming down-scaled yacht hulls it was intended to apply the findings obtained with the spherical dome parts to other 3-D shapes and to demonstrate the versatility and limitations of both processes.