1. Post Doc., Dept. of Marine Structures, Norwegian Univ. of Science and Technology, N-7491 Trondheim, Norway; Mailing address: R&D Materials Technology, Hydro Aluminum as, N-4265 Havik, Norway.
2. Professor, Dept. of Marine Structures, Norwegian Univ. of Science and Technology, N-7491 Trondheim, Norway.