scholarly journals Fatigue Reliability Assessment for Orthotropic Steel Bridge Decks Considering Load Sequence Effects

2021 ◽  
Vol 8 ◽  
Author(s):  
Jun-Hong Xu ◽  
Guang-Dong Zhou ◽  
Tai-Yong Zhu
Keyword(s):  
Bridge Decks ◽  
Fatigue Loading ◽  
Steel Bridge ◽  
Fatigue Reliability ◽  
Weld Joints ◽  
Initial Damage ◽  
Sequence Effects ◽  
Load Sequence ◽  
Orthotropic Steel Decks

Fatigue damage accumulations would dramatically reduce the reliability and service life of the orthotropic steel decks. Incorrect fatigue assessment results may be obtained when load sequence effects are omitted. In the present study, fatigue reliability assessments of rib-to-deck weld joints in orthotropic steel bridge decks are conducted with the consideration of load sequence effects. The method, which judiciously considers the fatigue loading history and is derived from the sequential law and the whole-range S-N curve, is first proposed for fatigue reliability calculation. And then, the whole-range S-N curve describing the fatigue propagating process of the rib-to-deck weld joint is introduced. Finally, the developed method is applied to evaluate the fatigue reliability of two rib-to-deck weld joints in an orthotropic steel deck based on long-term measured strain histories. The influence of traffic growth and initial damage on the fatigue reliability is discussed. The results indicate that it is advisable to consider load sequence effects when assessing the fatigue reliability of orthotropic steel decks equipped with long-term strain monitoring systems and the initial damage significantly reduces the fatigue reliability of orthotropic steel decks.

Floor-Beam Web Cutout Shape Analysis to Improve the Fatigue Resistance in Orthotropic Steel Bridge Decks

2010 ◽  
Vol 452-453 ◽  
pp. 161-164 ◽  
Author(s):  
Chun Sheng Wang ◽  
Qin Zhang ◽  
Tao Zhang ◽  
Ya Cheng Feng
Keyword(s):  
Bridge Deck ◽  
Fatigue Cracks ◽  
Bridge Decks ◽  
Steel Bridges ◽  
Steel Bridge ◽  
Analysis Model ◽  
Critical Question ◽  
Static Test ◽  
Orthotropic Steel Decks ◽  
Steel Orthotropic Deck

The modern steel orthotropic decks have been used in steel bridges for 60 years all over the world because of its super structural advantages. Recently, more bridge owners, engineers and researchers pay more attention to the fatigue problem of orthotropic steel decks for a large number of fatigue cracks found in steel bridges. For example, bridge engineers have detected hundreds of fatigue cracks in steel orthotropic deck on the 888-meter long box girder of Humen Bridge only ten years after opening to traffic. How to design or repair the fatigue details in orthotropic steel decks is the critical question to be solved at first step. In current paper, the elaborate numerical analysis model of the orthotropic steel bridge decks was developed using ANSYS software with different floor-beam web cutouts shapes, such as conventional ellipse, circular, trapezoid and Haibach web cutouts. The finite element models were calibrated by static test of one full size orthotropic steel bridge deck model. According to the analysis results, it should select the rational cutout shapes based on actual load and structural conditions in steel bridge deck design and strengthening.

scholarly journals Fatigue Reliability Assessment of Orthotropic Bridge Decks under Stochastic Truck Loading

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yang Liu ◽  
Xinhui Xiao ◽  
Naiwei Lu ◽  
Yang Deng
Keyword(s):  
Bridge Decks ◽  
Volume Growth ◽  
Reliability Assessment ◽  
Element Model ◽  
Traffic Volume ◽  
Traffic Load ◽  
Steel Bridge ◽  
Fatigue Reliability ◽  
Load Model ◽  
Gross Vehicle Weight

A steady traffic growth has posed a threat to the fatigue safety of existing bridges. Uncertainties in traffic flows add to the challenge of an accurate fatigue safety assessment. This article utilizes a stochastic traffic load model to evaluate the fatigue reliability of orthotropic steel bridge decks. The traffic load model is simulated by site-specific weigh-in-motion measurements. A response surface method is presented to solve the time-consuming problem caused by hotspot stress simulations in the finite element model. Applications of the stochastic traffic load model for probabilistic modeling and fatigue reliability assessment are demonstrated in the case study of a steel box-girder bridge. Numerical results indicate that the growth rate of the gross vehicle weight leads to a rapid decrease of the fatigue reliability in comparison to the traffic volume growth. Even though the traffic volume growth is rapid, the control of overloaded trucks in comparison to the traffic volume is an effective way to ensure the fatigue safety of the steel bridges.

Fatigue Tests of Overlapping Details for Orthotropic Steel Bridge Decks and Transverse Beams of Stay Cables

2012 ◽  
Vol 446-449 ◽  
pp. 3202-3206
Author(s):  
Guang Liang Bai ◽  
Guang Wu Tang
Keyword(s):  
Cyclic Loading ◽  
Moving Load ◽  
Bridge Decks ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Test Model ◽  
Steel Bridge ◽  
Loading Test ◽  
Stay Cables ◽  
Space Stress

Rail-cum-road cable-stayed bridge with single cable plane is eccentric under moving load, overlapping details for orthotropic steel bridge decks and transverse beams of stay cables are in typical complex space stress condition. A fatigue test is performed to evaluate anti-fatigue performance of overlapping details under the combination of highway and light railway loads. A 1:1 model is adopted for the overlapping details, where a fatigue loading test for 2×106 cycles is carried out. Its test results show: the structural stress level is low, no crack is found on the test model after cyclic loading for 2×106 cycles, then load amplitude is gradually increased and no crack is found after cyclic loading for 4.25×106 cycles, finally a result is obtained that no fatigue crack will be found on the overlapping details for orthotropic steel bridge decks and transverse beams of stay cables within design life, because fatigue strength requirements are satisfied.

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