Abstract
In order to obtain the degree of damage in reinforced concrete (RC) beams exposed to fire, using the equivalent fire exposure time as the damage index, a new method of damage identification based on the support vector machine technology was proposed. Firstly, the feasibility analysis was conducted based on finite element models of simply supported beams. Thereafter, four RC simply supported beams were designed for fire test and vibration test, which were used to amend the finite element model and the SVM-based identification method. Fire tests were carried out on 4 beams for 60, 90, 120, and 150 min, respectively. During and after the fire tests, structural modal information were recorded. The first two order modal information, as SVM input paraments, was used to predict the equivalent fire exposure time based on SVM. The predicted results were very close to the actual fire exposure time. The residual bearing capacities of the beams after fire were calculated according to the predicted fire exposure time, which were close to experimental results. It indicated that the equivalent fire exposure time as the output parameter for damage identification was reliable. Finally, on the basis of damage identification method for simply supported beams, a new three-step positioning method was established for identifing the degree of damage in continuous beams. The method was applied to a thress-span continuous beam. The numercial situlation results revealed that the three-step positioning method was accurate.
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Acknowledgements
The authors are grateful to editors and anonymous referees for their very valuable comments and suggestions, which have significantly helped improve the quality of this paper. This research work was supported by the National Natural Science Foundation of China (Grant No. 51608289), the China Postdoctoral Science Foundation (Grant No. 2018 M632640), the Qingdao Postdoctoral Applied Research Project (Grant No. 2018103), the Tianjin Transportation Science and Technology Development Project (No. 2016A-02) and the First-Class Discipline Project Funded by the Education Department of Shandong Province. The financial support is highly appreciated.
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Liu, C., Liu, C., Liu, C. et al. Fire Damage Identification in RC Beams based on Support Vector Machines considering Vibration Test. KSCE J Civ Eng 23, 4407–4416 (2019). https://doi.org/10.1007/s12205-019-2353-7
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DOI: https://doi.org/10.1007/s12205-019-2353-7