当前位置: X-MOL 学术J. Constr. Steel Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Fatigue strength of misaligned non-load-carrying cruciform joints made of ultra-high-strength steel
Journal of Constructional Steel Research ( IF 4.1 ) Pub Date : 2020-12-01 , DOI: 10.1016/j.jcsr.2020.106334
A. Ahola , T. Björk

Abstract Misalignments and distortions in welded plate components act as stress raisers and can significantly decrease the fatigue strength of welded connections. This paper investigates the effect of the plate misalignment of transverse attachments on the fatigue behavior of axially-loaded non-load-carrying cruciform (NLCX) joints. Experimental fatigue tests with and without the plate misalignment are carried out for fillet-welded NLCX joints. The test specimens were fabricated of S1100 ultra-high-strength steel grade, and the fatigue tests were conducted using an applied stress ratio of R = 0.1. Numerical finite element analyses were conducted to obtain the stress concentrations induced by the misalignment. In addition, varied geometry parameters were applied to investigate their effect on the magnitude of stress concentrations. Stress concentrations were obtained using the structural hot spot stress method applying linear surface extrapolation and 1 mm below depth methods, and the effective notch stress concept with the reference radius of 1 mm. Experimental fatigue tests showed a decrease of up to 12% in fatigue strength depending on the degree of misalignment. The highest stress concentration was induced when the misalignment to the joint width ratio was e/L = 0.2–0.4. Structural stresses cannot be estimated using the linear surface extrapolation. Instead, structural stress at the 1 mm depth and effective notch stress concept accurately evaluated the misalignment effect on the fatigue performance of NLCX joints, and provided a good correspondence between the theoretical and experimental fatigue strength estimations.

中文翻译:

超高强钢错位非承载十字接头的疲劳强度

摘要 焊接板部件中的错位和扭曲是应力集中器,会显着降低焊接连接的疲劳强度。本文研究了横向附件的板错位对轴向加载非承载十字形 (NLCX) 接头疲劳行为的影响。对角焊 NLCX 接头进行了带板错位和不带板错位的实验疲劳测试。试样由 S1100 超高强度钢制成,疲劳试验采用 R = 0.1 的外加应力比进行。进行数值有限元分析以获得由未对准引起的应力集中。此外,还应用了不同的几何参数来研究它们对应力集中大小的影响。应力集中是使用结构热点应力法应用线性表面外推法和 1 毫米以下深度方法以及参考半径为 1 毫米的有效缺口应力概念获得的。实验疲劳测试表明,根据错位程度,疲劳强度最多下降 12%。当与接头宽度比的偏差为 e/L = 0.2-0.4 时,会引起最高应力集中。不能使用线性表面外推法估计结构应力。相反,1 mm 深度处的结构应力和有效缺口应力概念准确地评估了不对中对 NLCX 接头疲劳性能的影响,并在理论和实验疲劳强度估计之间提供了良好的对应关系。
更新日期:2020-12-01
down
wechat
bug