Fatigue crack propagation behaviors of two weathering steels and the compatible welding material

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics Pub Date : 2025-08-24 DOI:10.1016/j.tafmec.2025.105192

Xiaoqing Xu , Kaixiang Miao , Yuqing Liu , Rui Hao

{"title":"Fatigue crack propagation behaviors of two weathering steels and the compatible welding material","authors":"Xiaoqing Xu , Kaixiang Miao , Yuqing Liu , Rui Hao","doi":"10.1016/j.tafmec.2025.105192","DOIUrl":null,"url":null,"abstract":"<div><div>Weathering steel has been increasingly applied in bridge engineering, meriting its strong atmospheric corrosion resistance, low life-cycle cost, and environmental friendliness. However, the fatigue performance and crack propagation evaluation of weathering steel welded connections are yet well understood. To investigate the widely used two weathering steel grades (Q345qDNH and Q420qDNH) in China and their corresponding compatible welding material THQ500-NQ-II, this paper performed fatigue tests on 33 compact tension (CT) specimens. The fatigue tests include three load ratios (R = 0.1, 0.3, and 0.5), and specimens made of Q345qDNH and THQ500-NQ-II are milled from the original thickness to different thickness (8, 14, 16, and 20 mm), in order to study the effects of load ratio and thickness on fatigue crack propagation. In addition, to study the effect of elastic compressive loading history, two intact specimens are extracted from a full-scale fatigue specimen that has been subjected to millions of loading cycles. The collected data includes fatigue crack length a, fatigue life N, fatigue crack propagation rate da/dN and stress intensity factor range ΔK. The calibration of Paris parameter C and m is achieved by linear fitting algorithm. The results show that compared to Q420qDNH, Q345qDNH yields a slightly lower da/dN under the same ΔK, and the welding material has better fatigue crack propagation resistance than base metal. Greater thickness for base material contributes to a better fatigue crack propagation resistance when ΔK is high but has limited effect when ΔK is low. The increase of load ratio R can accelerate the fatigue crack propagation, and it also raises the Paris parameter m linearly for Q345qDNH and decreases the logC linearly for both Q345qDNH and Q420qDNH. A consistent compressive loading history can contribute to retard the fatigue crack propagation under the same ΔK.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"140 ","pages":"Article 105192"},"PeriodicalIF":5.6000,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Theoretical and Applied Fracture Mechanics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167844225003507","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Weathering steel has been increasingly applied in bridge engineering, meriting its strong atmospheric corrosion resistance, low life-cycle cost, and environmental friendliness. However, the fatigue performance and crack propagation evaluation of weathering steel welded connections are yet well understood. To investigate the widely used two weathering steel grades (Q345qDNH and Q420qDNH) in China and their corresponding compatible welding material THQ500-NQ-II, this paper performed fatigue tests on 33 compact tension (CT) specimens. The fatigue tests include three load ratios (R = 0.1, 0.3, and 0.5), and specimens made of Q345qDNH and THQ500-NQ-II are milled from the original thickness to different thickness (8, 14, 16, and 20 mm), in order to study the effects of load ratio and thickness on fatigue crack propagation. In addition, to study the effect of elastic compressive loading history, two intact specimens are extracted from a full-scale fatigue specimen that has been subjected to millions of loading cycles. The collected data includes fatigue crack length a, fatigue life N, fatigue crack propagation rate da/dN and stress intensity factor range ΔK. The calibration of Paris parameter C and m is achieved by linear fitting algorithm. The results show that compared to Q420qDNH, Q345qDNH yields a slightly lower da/dN under the same ΔK, and the welding material has better fatigue crack propagation resistance than base metal. Greater thickness for base material contributes to a better fatigue crack propagation resistance when ΔK is high but has limited effect when ΔK is low. The increase of load ratio R can accelerate the fatigue crack propagation, and it also raises the Paris parameter m linearly for Q345qDNH and decreases the logC linearly for both Q345qDNH and Q420qDNH. A consistent compressive loading history can contribute to retard the fatigue crack propagation under the same ΔK.

查看原文本刊更多论文

两种耐候钢及其兼容焊接材料的疲劳裂纹扩展行为

耐候钢以其抗大气腐蚀能力强、寿命周期成本低、环境友好等优点在桥梁工程中得到越来越多的应用。然而，对耐候钢焊接接头的疲劳性能和裂纹扩展评价还没有很好的认识。为研究国内广泛使用的两种耐候钢牌号（Q345qDNH和Q420qDNH）及其配套焊接材料THQ500-NQ-II，对33个致密拉伸试件进行了疲劳试验。疲劳试验采用三种载荷比（R = 0.1、0.3、0.5），将Q345qDNH和THQ500-NQ-II试样从原始厚度铣削至不同厚度（8、14、16、20 mm），研究载荷比和厚度对疲劳裂纹扩展的影响。此外，为了研究弹性压缩加载历史的影响，从经历了数百万次加载循环的全尺寸疲劳试件中提取了两个完整的试件。收集的数据包括疲劳裂纹长度a、疲劳寿命N、疲劳裂纹扩展速率da/dN和应力强度因子范围ΔK。采用线性拟合算法对Paris参数C和m进行标定。结果表明：在相同ΔK温度下，与Q420qDNH相比，Q345qDNH的da/dN略低，且焊接材料的抗疲劳裂纹扩展性能优于母材；当ΔK为高时，基材厚度越大，抗疲劳裂纹扩展性能越好；当ΔK为低时，基材厚度越小，抗疲劳裂纹扩展性能越好。载荷比R的增大可以加速疲劳裂纹扩展，同时使Q345qDNH的Paris参数m线性升高，并使Q345qDNH和Q420qDNH的logC线性降低。一致的压缩加载历史有助于延缓相同ΔK下的疲劳裂纹扩展。

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

Theoretical and Applied Fracture Mechanics 工程技术-工程：机械

CiteScore

8.40

自引率

18.90%

发文量

435

审稿时长

37 days

期刊介绍： Theoretical and Applied Fracture Mechanics'' aims & scopes have been re-designed to cover both the theoretical, applied, and numerical aspects associated with those cracking related phenomena taking place, at a micro-, meso-, and macroscopic level, in materials/components/structures of any kind. The journal aims to cover the cracking/mechanical behaviour of materials/components/structures in those situations involving both time-independent and time-dependent system of external forces/moments (such as, for instance, quasi-static, impulsive, impact, blasting, creep, contact, and fatigue loading). Since, under the above circumstances, the mechanical behaviour of cracked materials/components/structures is also affected by the environmental conditions, the journal would consider also those theoretical/experimental research works investigating the effect of external variables such as, for instance, the effect of corrosive environments as well as of high/low-temperature.