1. Muehlhan AG, Schlinckstraße 3, Hamburg 21107, Germany e-mail:
2. Fraunhofer Application Center for Large Structures in Production Engineering (AGP), Albert-Einstein-Straße 30, Rostock D-18059, Germany e-mail:
3. Fraunhofer Institute for Manufacturing and Advanced Materials Research (IFAM), Wiener Straße 12, Bremen D-28359, Germany e-mail: