Fatigue behaviour of welded joints in offshore steel structures - Part 1 : Thick plates
Earlier fatigue research up to a plate thickness of 76 mm showed that an increase of the plate thickness has a decreasing effect on the fatigue performance. Since the plate thickness applied in offshore structures tends to increase with the dimensions of those structures, fatigue research has been carried out on thick plates in this project. Plate specimens in the as-welded condition with thicknesses of 70 and 160 mm were tested in air with constant amplitude loading (R = 0.1) under four point bending. Three types of specimens were investigated (butt welds, transverse attachments and longitudinal attachments). The experiments show that the thickness effect is not limited at 70 mm, but that up to a thickness of 160 mm of the main plate the thicknesses of both the main plate and the attachments have a significant influence on the fatigue strength. The influences of the main plate and the attachments are of the same order. Analysis of the results of this programme and previous programmes on the fatigue behaviour of as-welded specimens by multiple regression analysis results in the following relation between stress range S(r), fatigue life N, thickness T of main plate and thickness t of attachment: log(S(r)) = C - 0.33log(N) - 0.15log(T) - 0.15log(t). From this analysis the influence of the thickness of the main plate is apparently equal to the influence of the thickness of the attachment.
Bibliographic Reference: EUR 13395 EN (1992) Vol. 1, 212 pp., FS, ECU 17.50
ISBN: ISBN 92-826-3623-2
Record Number: 199210349 / Last updated on: 1994-12-02
Original language: en
Available languages: en