Fatigue behaviour of welded joints assembled by longitudinal corrugated plates
来源期刊：中南大学学报(英文版)2015年第7期
论文作者：WANG Zhi-yu WANG Qing-yuan Liu Yong-jie Sun Mei
文章页码：2752 - 2760
Key words：corrugated web; fatigue behaviour; S-N relation; stiffness degradation; fracture mechanics
Abstract: Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.
WANG Zhi-yu(王志宇)1, 2, WANG Qing-yuan(王清远)1, 2, Liu Yong-jie(刘永杰)1, 2, Sun Mei(孙美)3
(1. Department of Civil Engineering & Mechanics, Institute of Architecture and Environment,
Sichuan University, Chengdu 610065, China;
2. Sichuan Provincial Key Laboratory of Failure Mechanics and Engineering Disaster Prevention & Mitigation,
(Sichuan University), Chengdu 610065, China;
3. Department of Accounting and Corporate Finance, Business School, Sichuan University, Chengdu 610065, China)
Abstract:Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints.
Key words:corrugated web; fatigue behaviour; S-N relation; stiffness degradation; fracture mechanics
