Structural safety assessment of continuous girder bridge with fatigue crack in web plate

2015 ◽  
Vol 8 (1) ◽  
pp. 15-20
Author(s):  
Kunitaro Hashimoto ◽  
Makio Kayano ◽  
Yasuo Suzuki ◽  
Kunitomo Sugiura ◽  
Eiichi Watanabe
2006 ◽  
Vol 321-323 ◽  
pp. 603-606
Author(s):  
Jung Seok Kim ◽  
Nam Po Kim ◽  
Seong Ho Han

This study has performed the experimental study to assess the structural safety of a bolster frame that is applied to the bogie system of Korean tilting train. In order to achieve this goal, firstly, loading conditions imposed on the bolster frame were investigated. Based on the international standard and dynamic analysis, the loading conditions were derived. In this study, the dynamic load cases that consider the carbody tilting effect were established. The structural safety of the bolster frame was evaluated by static test under these static loads and the fatigue strength was assessed using Goodman diagram. From the assessment, the bolster frame has satisfied the structural safety. In addition, fatigue test was carried out up to 1x107cycles under tilting load condition established in this study. The inspection of fatigue crack using NDT method was conducted at 6x106 and 1x107 cycles.


Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1758
Author(s):  
Koji Tsuchimoto ◽  
Yasutaka Narazaki ◽  
Billie F. Spencer

After a major seismic event, structural safety inspections by qualified experts are required prior to reoccupying a building and resuming operation. Such manual inspections are generally performed by teams of two or more experts and are time consuming, labor intensive, subjective in nature, and potentially put the lives of the inspectors in danger. The authors reported previously on the system for a rapid post-earthquake safety assessment of buildings using sparse acceleration data. The proposed framework was demonstrated using simulation of a five-story steel building modeled with three-dimensional nonlinear analysis subjected to historical earthquakes. The results confirmed the potential of the proposed approach for rapid safety evaluation of buildings after seismic events. However, experimental validation on large-scale structures is required prior to field implementation. Moreover, an extension to the assessment of high-rise buildings, such as those commonly used for residences and offices in modern cities, is needed. To this end, a 1/3-scale 18-story experimental steel building tested on the shaking table at E-Defense in Japan is considered. The importance of online model updating of the linear building model used to calculate the Damage Sensitive Features (DSFs) during the operation is also discussed. Experimental results confirm the efficacy of the proposed approach for rapid post-earthquake safety evaluation for high-rise buildings. Finally, a cost-benefit analysis with respect to the number of sensors used is presented.


Author(s):  
Qiwen Jin ◽  
Zheng Liu

In-service bridges, under long-term service operational environment, are usually accompanied by different damage types. Traditional method for the measure point arrangement of in-service bridge SHM is usually based on engineering experience. A large number of SHM sensors are usually arranged on the structure, followed by a high engineering cost and a heavy maintenance task. These sensors will also produce large amounts of data, creating a challenge for operators requiring to deal with data processing in an effective manner. This study serves as a part of the series of studies on the measure point arrangement strategy of in-service bridge SHM. In this study, the SHM sensor measure point arrangement of in-service continuous girder bridge (a common structural style of high way bridge in China) is proposed. Two-span continuous beam, three-span continuous beam, and four-span continuous beam are taken as examples. Detailed comparison and verification are also performed with consideration of numerical simulation and previous studies. Different traffic speeds and different bridge spans are considered. The effect of different damage locations and different damage degrees are analyzed in detail. This study shows that a general similar trend can be observed for the structural robustness of in-service continuous girder bridge. The elements with smaller structural robustness of this kind of bridge are basically located around the middle cross section of side spans (first span and last span), followed by the middle span. Moreover, the numerical value of structural robustness of different elements in a continuous girder bridge is significantly different from each other, due to the complexity of the joint effect of different traffic speeds and damage locations. Therefore, the measure point should be generally arranged at the side span firstly, followed by the middle span. With consideration of the specific traffic speed and damage location in engineering application, a detailed analysis is also proposed for the further optimization of SHM sensor measure point arrangement. Once the elements are arranged in order of the numerical value of structural robustness, the SHM sensor measure point arrangement of this kind of bridge can be more targeted, and the number of sensors can also be greatly reduced.


2014 ◽  
Vol 1036 ◽  
pp. 935-940
Author(s):  
Leonard Domnisoru ◽  
Ionica Rubanenco ◽  
Mihaela Amoraritei

This paper is focused on an enhanced integrated method for structural safety assessment of maritime ships under extreme random wave loads. In this study is considered an 1100 TEU container test ship, with speed range 0 to 18 knots. The most comprehensive criteria for ships structural safety evaluation over the whole exploitation life is based on the long term ship structures analysis, that includes: stress hot-spots evaluation by 3D/1D-FEM hull models, computation of short term ship dynamic response induced by irregular waves, long term fatigue structure assessment. The analysis is enhanced by taking into account the ships speed influence on hydroelastic response. The study includes a comparative analysis on two scenarios for the correlation between the ships speed and waves intensity. The standard constant ship speed scenario and CENTEC scenario, with total speed loss at extreme waves condition, are considered. Instead of 20 years ship exploitation life estimated by classification societies rules from the long term structural safety criteria, the enhanced method has predicted more restrictive values of 14.4-15.7 years. The numerical analyses are based on own software and user subroutines. The study made possible to have a more realistic approach of ships structural strength assessment, for elastic and faster ships as container carriers, in compare to the standard one based only on naval rules, delivering a method with higher confidence in the designed structural safety.


2017 ◽  
Vol 31 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Zhi-qiang Hu ◽  
Dong-wei Zhang ◽  
Dong-ya Zhao ◽  
Gang Chen

2011 ◽  
Vol 280 ◽  
pp. 186-190
Author(s):  
Shou Tan Song ◽  
Ji Wen Zhang ◽  
Xin Yuan

The dynamic performance of continuous girder under the train in a series of speed is studied through examples, and the main conclusions are given in the following. The resonance mechanism of continuous girder is similar to simply supported beam. The vehicle wheel load forms regular moving load series, which induces periodical action and resonance of the bridge. The damping ratio of bridge itself has less effect on the amplitude at the loading stage, but significant effects appear when the load departs from the bridge. The count of continuous spans also has less impact on the dynamic coefficients, so three continuous spans can be adopted for calculation and analysis. Span and fundamental frequency have significant influence on dynamic coefficients of bridge structures. To extend the span of the bridge structure can reduce the dynamic coefficient while keeping its frequency invariant. The fundamental frequencies of different bridges are corresponding to certain resonant speeds, which calls for the attention in the design.


2013 ◽  
Vol 23 (2) ◽  
pp. 198-203 ◽  
Author(s):  
Akira Igarashi ◽  
Hiroyuki Ouchi ◽  
Tetsuo Matsuda ◽  
Hiroshige Uno ◽  
Hiroshi Matsuda ◽  
...  

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