PSI - Issue 57

Gloria Hofmann et al. / Procedia Structural Integrity 57 (2024) 452–460 Hofmann, G.; Bartsch, H.; Kuhlmann, U.; Feldmann, M.

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however, did not meet this criterion. The distinctly worse test results of these test specimens show that the limitation to a misalignment of < 5% of the plate thickness is justified. Therefore, these test results were not considered in the evaluation. All specimens were run until complete failure. Although the cyclic loads were stopped before complete rupture, during the following static tension loading until complete fracture, the maximum load was no longer reached. As expected, the crack initiation appeared at the weld toe and propagated both through the plate and along the weld transition zone. A butt joint with a crack half way through the 80 mm thick plate and the test results combined with various other results are shown in Fig. 2.

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Collected experiments [6] Polezhayeva, Badger [8]

Kim et al. [7]

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Experiments University of Stuttgart [6]

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b) Fig. 2: a) Transversebutt joint,t = 80 mm with crack,b) Various test results of butt-welded joints as welded (Hofmann, in preparation). The test results of our experiments show the same tendency as can be seen with the other series (Kim, Lee, & Jung, 2009), (Polezhayeva & Badger, 2009), (Kang, 2016) focusing on the plate thickness influence. Even though the fatigue strength of the various series differs largely, resulting in a large scatter in the results, the fatigue strength for all plate thicknesses is found in the same range within the individual series. 3. Longitudinal attachments

3.1. State of the art

According to the Eurocode 3 Part 1-9 (EN 1993-1-9, 2005), the fatigue strength of longitudinal attachments is affected by various factors. One influencing factor is the length of the attachment. Both the Eurocode 1993-1-9 and various test results (Hirt & Crisinel, 1975), (Puthli, Herion, & Bergers, 2006), including our tests with attachment lengths of 100, 250 and 500 mm, show decreasing fatigue strengths with increasing lengths, as shown in Fig. 3.

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Fig. 3: Various test results of longitudinal attachments with different length (Feldmann, et al., exp. 2024)