The Influence of the Load Variation on Fatigue Strength of the Spot Welded Joint using the High Strength Steel
The Influence of the Load Variation on Fatigue Strength of the Spot Welded Joint using the High Strength Steel
复制标题
载荷变化对高强钢点焊接头疲劳强度的影响
DOI：
10.1016/j.proeng.2011.04.561
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
A.Sugeta
中科院分区：
文献类型：
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作者：
R.Tanegashima;H.Akebono;M.Kato;A.Sugeta
在这项研究中，我们进行了三维观察的疲劳裂纹扩展的点焊接头使用高强度钢，以考虑其疲劳特性。结果表明，尽管应力水平不同，但它们的疲劳裂纹表现出几乎相同的行为。而且，在寿命的大部分时间内，需要多次循环载荷才能引发疲劳裂纹。因此，我们建议，它是能够使用相同的标准，在任何应力水平下，恒定的应力幅下的疲劳特性进行评估。此外，我们进行了变幅载荷条件下的疲劳试验，以研究载荷变化对点焊接头的疲劳性能的影响，因为实际的汽车已采取变载荷。然后，点焊接头的疲劳极限在变载荷条件下消失。此外，我们明确了点焊接头的疲劳寿命可以使用修改的Miner定律进行评估。
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.