Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints
The division of the total fatigue life into different stages such as crack initiation and propagation is an important issue in regard to an improved fatigue assessment especially for high-strength welded joints. The transition between these stages is fluent, whereas the threshold between the two pha...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-10-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/9/21/4590 |
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| author | Markus J. Ottersböck Martin Leitner Michael Stoschka Wilhelm Maurer |
| author_facet | Markus J. Ottersböck Martin Leitner Michael Stoschka Wilhelm Maurer |
| author_sort | Markus J. Ottersböck |
| collection | DOAJ |
| description | The division of the total fatigue life into different stages such as crack initiation and propagation is an important issue in regard to an improved fatigue assessment especially for high-strength welded joints. The transition between these stages is fluent, whereas the threshold between the two phases is referred to as technical crack initiation. This work presents a procedure to track crack initiation and propagation during fatigue tests of ultra high-strength steel welded joints. The method utilizes digital image correlation to calculate a distortion field of the specimens’ surface enabling the identification and measurement of cracks along the weld toe arising during the fatigue test. Hence, technical crack initiation of each specimen can be derived. An evaluation for ten ultra high-strength steel butt joints reveals, that for this superior strength steel grade more than 50% of fatigue life is spent up to a crack depth of 0.5 mm, which can be defined as initial crack. Furthermore, a notch-stress based fatigue assessment of these specimens considering the actual weld topography and crack initiation and propagation phase is performed. The results point out that two phase models considering both phases enable an increased accuracy of service life assessment. |
| first_indexed | 2024-12-13T05:02:44Z |
| format | Article |
| id | doaj.art-8c08212d506a41b094814eda3319d740 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-13T05:02:44Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-8c08212d506a41b094814eda3319d7402022-12-21T23:58:44ZengMDPI AGApplied Sciences2076-34172019-10-01921459010.3390/app9214590app9214590Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt JointsMarkus J. Ottersböck0Martin Leitner1Michael Stoschka2Wilhelm Maurer3Chair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, AustriaChair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, AustriaChair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austriavoestalpine Stahl GmbH, voestalpine-Straße 3, 4020 Linz, AustriaThe division of the total fatigue life into different stages such as crack initiation and propagation is an important issue in regard to an improved fatigue assessment especially for high-strength welded joints. The transition between these stages is fluent, whereas the threshold between the two phases is referred to as technical crack initiation. This work presents a procedure to track crack initiation and propagation during fatigue tests of ultra high-strength steel welded joints. The method utilizes digital image correlation to calculate a distortion field of the specimens’ surface enabling the identification and measurement of cracks along the weld toe arising during the fatigue test. Hence, technical crack initiation of each specimen can be derived. An evaluation for ten ultra high-strength steel butt joints reveals, that for this superior strength steel grade more than 50% of fatigue life is spent up to a crack depth of 0.5 mm, which can be defined as initial crack. Furthermore, a notch-stress based fatigue assessment of these specimens considering the actual weld topography and crack initiation and propagation phase is performed. The results point out that two phase models considering both phases enable an increased accuracy of service life assessment.https://www.mdpi.com/2076-3417/9/21/4590fatigue strengthultra high-strength steelbutt jointsweld topographycrack detection and trackingcrack propagation |
| spellingShingle | Markus J. Ottersböck Martin Leitner Michael Stoschka Wilhelm Maurer Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints Applied Sciences fatigue strength ultra high-strength steel butt joints weld topography crack detection and tracking crack propagation |
| title | Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints |
| title_full | Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints |
| title_fullStr | Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints |
| title_full_unstemmed | Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints |
| title_short | Crack Initiation and Propagation Fatigue Life of Ultra High-Strength Steel Butt Joints |
| title_sort | crack initiation and propagation fatigue life of ultra high strength steel butt joints |
| topic | fatigue strength ultra high-strength steel butt joints weld topography crack detection and tracking crack propagation |
| url | https://www.mdpi.com/2076-3417/9/21/4590 |
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