Loosening phenomenon on thin plates bolted joint due to offset load

IF 3.8 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY
Naoki Yamamoto , Takehiro Ohno , Shinji Hashimura
{"title":"Loosening phenomenon on thin plates bolted joint due to offset load","authors":"Naoki Yamamoto ,&nbsp;Takehiro Ohno ,&nbsp;Shinji Hashimura","doi":"10.1016/j.jajp.2024.100247","DOIUrl":null,"url":null,"abstract":"<div><p>In this study, the new loosening behavior was discovered and investigated when offset loads were repeatedly applied to both ends of a bolted joint initially tightened to a thin plate made of high-tensile steel. In the experiments, the impact of offset distance on reduction of clamp force was investigated through multiple applications of symmetric offset axial load to the bolted joint assembly. The experimental results showed that even a slight offset load reduced the clamp force, and the larger the offset distance, the greater the reduction of the clamp force. It was also found that the decrease in clamp force depends not on the number of times the offset load is applied but on the magnitude of the offset load. Until now even if the thin plate bolted joint was subjected to an offset load, as long the plates do not deform significantly due to plastic deformation, it has been generally recognized that the clamp force is not reduced. This loosening phenomenon is new and its mechanism has not been elucidated yet. In order to clarify the mechanism that may lower the clamp force, this study conducted FE analysis using a simplified model of a bolted joint. In the FE model, the bolt and nut are considered as a single unit and the effect of slippage between the thread surfaces and the effect of plastic deformation is ignored by using elastic analysis. The results of the FE analysis showed that the main factor causing the reduction in clamp force was slippage between the thin plates to be joined, which was caused by offset load, and that the slippage didn't return to the original position resulting in the reduction in clamp force.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100247"},"PeriodicalIF":3.8000,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000633/pdfft?md5=003ec95187e4c76c2e1311bb8b75939d&pid=1-s2.0-S2666330924000633-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Advanced Joining Processes","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666330924000633","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0

Abstract

In this study, the new loosening behavior was discovered and investigated when offset loads were repeatedly applied to both ends of a bolted joint initially tightened to a thin plate made of high-tensile steel. In the experiments, the impact of offset distance on reduction of clamp force was investigated through multiple applications of symmetric offset axial load to the bolted joint assembly. The experimental results showed that even a slight offset load reduced the clamp force, and the larger the offset distance, the greater the reduction of the clamp force. It was also found that the decrease in clamp force depends not on the number of times the offset load is applied but on the magnitude of the offset load. Until now even if the thin plate bolted joint was subjected to an offset load, as long the plates do not deform significantly due to plastic deformation, it has been generally recognized that the clamp force is not reduced. This loosening phenomenon is new and its mechanism has not been elucidated yet. In order to clarify the mechanism that may lower the clamp force, this study conducted FE analysis using a simplified model of a bolted joint. In the FE model, the bolt and nut are considered as a single unit and the effect of slippage between the thread surfaces and the effect of plastic deformation is ignored by using elastic analysis. The results of the FE analysis showed that the main factor causing the reduction in clamp force was slippage between the thin plates to be joined, which was caused by offset load, and that the slippage didn't return to the original position resulting in the reduction in clamp force.

偏载导致薄板螺栓连接处出现松动现象
在本研究中,我们发现并研究了一种新的松动行为,即在最初拧紧在高强度钢薄板上的螺栓连接两端反复施加偏置载荷。在实验中,通过对螺栓连接组件多次施加对称偏置轴向载荷,研究了偏置距离对夹紧力降低的影响。实验结果表明,即使是轻微的偏移载荷也会降低夹紧力,而且偏移距离越大,夹紧力的降低幅度越大。实验还发现,夹紧力的减小并不取决于施加偏置载荷的次数,而是取决于偏置载荷的大小。迄今为止,即使薄板螺栓连接承受了偏置载荷,只要薄板没有因塑性变形而发生显著变形,夹紧力就不会降低,这一点已得到普遍认可。这种松动现象是一种新现象,其机理尚未阐明。为了阐明可能降低夹紧力的机理,本研究使用螺栓连接的简化模型进行了有限元分析。在有限元模型中,螺栓和螺母被视为一个整体,通过弹性分析,忽略了螺纹表面之间的滑动效应和塑性变形效应。有限元分析的结果表明,导致夹紧力降低的主要因素是由偏移载荷引起的待连接薄板之间的滑动,而这种滑动不会恢复到原来的位置,从而导致夹紧力降低。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
7.10
自引率
9.80%
发文量
58
审稿时长
44 days
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信