The Influence of the Load Variation on Fatigue Strength of the Spot Welded Joint using the High Strength Steel

✍ Scribed by Ryota Tanegashima; Hiroyuki Akebono; Masahiko Kato; Atsushi Sugeta

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 571 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.561

✦ Synopsis

In this study, we conducted three dimensional observation of the fatigue crack propagation in the spot welded joints using the high strength steel in order to consider their fatigue characteristics. As this result, their fatigue crack indicated almost the same behaviour nevertheless the stress level. And, many cyclic loading were required to initiate the fatigue crack in large part of the life. Therefore, we suggested it is enabled to evaluate fatigue characteristics using the same criterion in any stress level under the constant stress amplitude. Moreover, we carried out fatigue tests under variable amplitude loading conditions to investigate the influence of load variation on fatigue properties of the spot welded joints since actual automobiles have been taken varying loading. Then, the fatigue limit of the spot welded joints was vanished under variable loading conditions. Furthermore, we cleared that the fatigue life of the spot welded joints could be evaluated using a modified Miner's law.