Comparison of local fatigue assessment methods for high-quality butt-welded joints made of high-strength steel

Fatigue strength of welded joints is typically independent of the parent material static strength; however, there are two exceptions from this rule—post-weld treated joints and high-quality joints. The reason for both is the absence of sharp weld transitions. Thus, fatigue life is not fully governed by fatigue crack propagation but also by fatigue crack initiation. This is intensified by the fact that crack initiation behaviour is proportional to static strength properties. Commonly, this effect is not accounted for by design guidelines and typical fatigue assessment methods for welded joints. This study hence investigates the applicability and accuracy of different local fatigue assessment methods for high-quality welded joints made of high-strength steel. For this purpose, fatigue test results of S500 structural steel joints with weld toe and weld root failure are assessed using a variety of local approaches and then compared to the nominal stress approach. Finally, the transferability of results to large-scale structures are discussed and recommendations are given for practical applications.

Subjects

4R method

Effective notch stress approach

Fatigue testing

Peak stress method

Stress averaging approach

Structural hot-spot stress approach

Theory of critical distances

DDC Class

600: Technik

Publication version

publishedVersion

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

1-s2.0-S2666359721000470-main.pdf

Size

3.18 MB

Format

Adobe PDF

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Comparison of local fatigue assessment methods for high-quality butt-welded joints made of high-strength steel