Comparison of fatigue strength of post-weld improved high strength steel joints and notched base material specimens. (30th April 2018)

• Record Type: Journal Article
• Authors: Braun, Moritz; Grimm, Jan-Hendrik; Hoffmeister, Hasso; Ehlers, Sören; Fricke, Wolfgang
• Is Part Of: Ships and offshore structures. Volume 13(2018)Supplement 1
• Page Start: 47
• Page End: 55
• Publication Date: 2018-04-30
• Subjects: Post-weld treatment -- high strength steel -- fatigue testing -- fatigue life improvement -- weld toe grinding; Ships -- Periodicals; Offshore structures -- Periodicals; Marine engineering -- Periodicals; Marine engineering -- Technological innovations -- Periodicals; Ocean engineering -- Periodicals; Ocean engineering -- Technological innovations -- Periodicals; 623.8
• DOI: 10.1080/17445302.2018.1425522
• Languages: English
• ISSNs: 1744-5302

Abstract

ABSTRACT: Keels of high-performance sailing yachts are highly stressed parts of the hull structure. Such keels are either milled or are welded hollow profiles. Recently a trend towards using high strength steel to manufacture keels is observed. While the fatigue strength of the parent material increases linearly with yield strength, it is independent of yield strength after welding. This problem can be overcome by post-weld improvement of the local weld geometry. Fatigue test results of the critical weld detail made from S900 steel are compared in welded state and after weld toe grinding. Additional tests of the same detail made from S355 steel, are performed. Moreover, tests of the notched parent material corresponding to a milled keel are presented. The fatigue strength of the grinded specimens was 2.2 times larger than in as-welded condition. The notched base material specimens act as an upper bound S-N curve for the post-weld improved specimens.