scholarly journals Analysis on Stop-hole Parameters for Fatigue Cracks at Arc Notch in Steel Bridge Deck

2022 ◽  
Vol 2148 (1) ◽  
pp. 012036
Author(s):  
Liangping Feng ◽  
Lipeng Ling ◽  
Cheng Meng ◽  
Bohai Ji

Abstract Two types of fatigue cracks at arc notch in steel bridge deck were repaired by drilling stop-holes. The effect of stop-holes with different diameters and positions was considered. Based on finite element models, the variation laws of stress distribution and the effects of stress concentration were compared for different stop-hole diameters and positions. Analysis results indicated that stop-hole can effectively improve the stress concentration at crack tip and the fatigue life of components can be considerably increased. The crack-stopping performance enhances with the increase of stop-hole diameter, but large stop-hole cannot effectively retard crack growth. The stop-hole performs well with the location at -0.5D∼0.5D. The maximum stress point still appears at crack tip when the stop-hole is outside or inside the crack. The stop-hole diameter has no effect on the stop-hole location.

2010 ◽  
Vol 452-453 ◽  
pp. 161-164 ◽  
Author(s):  
Chun Sheng Wang ◽  
Qin Zhang ◽  
Tao Zhang ◽  
Ya Cheng Feng

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.


2013 ◽  
Vol 639-640 ◽  
pp. 239-242
Author(s):  
Jian Hua Cheng ◽  
Jian Min Xiong ◽  
Jin Zhi Zhou

Orthotropic plate participates in bridge structure as a part of steel box girder, while in Balinghe Bridge it is used as bridge deck directly to endure the wheel load [1]. In this paper it’s studied systematically the mechanical behavior of orthotropic steel bridge deck in combination with the deck model of Balinghe Bridge, and shows the positions emerging fatigue cracks to provide the basis for future health monitoring and put forward some suggestions.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 417
Author(s):  
Xunqian Xu ◽  
Yuwen Gu ◽  
Wei Huang ◽  
Dakai Chen ◽  
Chen Zhang ◽  
...  

Fatigue cracks often occur in the deck asphalt pavement of steel bridges at the top of the longitudinal stiffening rib. To prevent this issue, the traditional design strategy of the steel bridge deck asphalt pavement structure was optimized, and a new approach is presented. This optimization technique exploits the strength simulation of the steel—epoxy asphalt pavement structure, and the stress concentration location is subsequently determined. A solid model of stress concentration including sensitive areas is then established. We examined the stress maximum point of the asphalt pavement layer at the top of the longitudinal stiffeners and the stress variation of the asphalt pavement layer at the top of the longitudinal stiffeners. To reduce the stress of the top pavement layer of the longitudinal stiffeners, an optimization method that combines orthogonal experimental design, neural network (BP), and genetic algorithm (GA) is presented. A design strategy for the steel—epoxy asphalt pavement structure and GA—BP optimization method was utilized to optimize the structure of the steel—epoxy asphalt pavement for Sutong Yangzi River Bridge. We confirmed that the presented approach improved fatigue reliability and established the efficacy of the design strategy and optimization method.


2010 ◽  
Vol 163-167 ◽  
pp. 3511-3516 ◽  
Author(s):  
Yan Ling Zhang ◽  
Yun Gang Zhang ◽  
Yun Sheng Li

In this paper, the stress distribution of the orthotropic steel bridge deck in a suspend bridge under local wheel load is analyzed. Some retrofitted methods are introduced, two of which are studied. One is using the concrete paving layer (CPL), and the other is using the sandwich plate system (SPS) to strengthen the orthotropic steel bridge deck. Local finite element models are established by ANSYS; stress distribution of bridge deck is calculated under the designed vehicle load before and after the deck retrofitted by the CPL or the SPS, and the results are compared with each other. The analysis results indicate that, under wheel pressure load, the orthotropic steel deck appears stress concentration; after the deck was retrofitted no matter by the CPL or the SPS, all the stress peaks decrease obviously, and the fatigue resistance of the orthotropic steel deck increases, which indicate that the two methods are effective to retrofit the orthotropic steel bridge deck. Using the CPL method can lead to lower stress concentration than that of using the SPS method, but the concrete paving layer is easy to crack, so, high performance concrete with high tension strength is needed.


Author(s):  
Ryo Nakata ◽  
Yukio Adachi

<p>Fatigue damage is a major topic in bridge maintenance. The fatigue damage to steel bridge deck has been dramatically increasing since the first fatigue damage was observed in Hanshin expressway in early 2000s. Insufficient knowledge of bridge fatigue design and unexpected increase of traffic demand and heavy vehicle could be the cause of the fatigue damage.</p><p>Replacement of base pavement course to steel fiber reinforced concrete (SFRC) has been generally used for strengthening of steel decks; however, the countermeasure from the topside of the bridge deck could make serious traffic disruption. Therefore, reactive and proactive maintenance for such steel decks has not been well progressed so far.</p><p>According to the background above, Hanshin expressway has been making an effort on developing new method by strengthening steel deck from the bottom side. The idea of the new method is to enhance fatigue resistance by improving the weld joint between deck plate and U-rib plate. Three potential methods were identified and the effectiveness of those methods was studied in field for making sure of not only fatigue resistance improvement but also field construction.</p><p>This paper will introduce the new retrofit methods for steel deck and describe the effectiveness of those methods.</p>


2011 ◽  
Vol 243-249 ◽  
pp. 1659-1663
Author(s):  
Yun Sheng Li ◽  
Yang Tian ◽  
Yan Ling Zhang

Orthotropic decks are commonly used in high-speed railway bridges. Finite-element model is established by ANSYS for orthotropic steel bridge deck in this paper. Taking the standard PDL ZK live load as the train load, the local stress of the rib-to-deck joint, the rib-to-crossbeam joint, and the cut-outs of the crossbeam are analyzed respectively. Analysis results show that the stress concentration of bridge deck mainly appears at the intersecting part of the U-shaped rib, crossbeam, and bridge deck. In the whole bridge deck, the local stress level of the cut-outs in crossbeam is almost the highest, and the cut-outs is distorted seriously; the maximum stress of crossbeam cut-outs is mainly concentrated at the lower arc of the cut-outs, which is one of the positions prone to fatigue failure.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 161 ◽  
Author(s):  
Datao Li ◽  
Chunguo Zhang ◽  
Pengmin Lu

By means of finite element modeling (FEM) and fatigue experiments, we study the fatigue performance of the rounded welding region between the diaphragm plate and closed rib of orthotropic steel bridge deck in this work. A local sub-model of the rounded welding region from the orthotropic steel bridge deck was developed to analyze the stress distributions. Based on the analysis results we designed the fatigue specimen for the fatigue test of this detailed structure. The fatigue experimental results revealed that the crack initiates from the weld toe of the rounded welding region and the stress concentration at the rounded welding region is the main mechanism of fatigue crack initiation. In addition, we propose three improvements to reduce the stress concentration of the rounded welding region, and the local structure optimization scheme of the diaphragm–rib weld can effectively improve the fatigue resistance of the detailed weld structure.


Author(s):  
Matthew Watkins ◽  
Mark Jakiela

This paper presents the use of a genetic algorithm in conjunction with geometric nonlinear finite element analysis to optimize the fastener pattern and lug location in an eccentrically loaded multi-fastener connection. No frictional resistance to shear was included in the model, as the connection transmitted shear loads into four dowel fasteners through bearing-type contact without fastener preload. With the goal of reducing the maximum von Mises stress in the connection to improve fatigue life, the location of the lug hole and four fastener holes were optimized to achieve 55% less maximum stress than a similar optimization using the traditional instantaneous center of rotation method. Since the maximum stress concentration was located at the edge of a fastener hole where fatigue cracks could be a concern, reduction of this quantity lowers the probability of crack growth for both bearing-type and slip-resistant connections. It was also found that the location of the maximum von Mises stress concentration jumped from the fastener region to the lug as the applied force angle was decreased below 45 degrees, thus the fastener pattern could not be optimized for lower angles.


2017 ◽  
Vol 31 (6) ◽  
pp. 04017094 ◽  
Author(s):  
Zhongqiu Fu ◽  
Qiudong Wang ◽  
Bohai Ji ◽  
Zhiyuan Yuanzhou

2021 ◽  
Vol 291 ◽  
pp. 123366
Author(s):  
Yang Liu ◽  
Zhendong Qian ◽  
Xijun Shi ◽  
Yuheng Zhang ◽  
Haisheng Ren

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