1.青岛理工大学 土木工程学院;2.河北工业大学 土木与交通学院
1.College of Civil Engineering,Qingdao University of Technology;2.School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin
National Natural Science Foundation of China (51608289) ; China Postdoctoral Research Foundation (2018M632640) ; Shandong Postdoctoral Innovation Program (2019057) ; Qingdao Postdoctoral Applied Research Program (2018103)
为全面准确地评估钢筋混凝土梁的火灾损伤状态,结合火灾试验和数值仿真多元信息,提出了钢筋混凝土梁(RC梁)火灾损伤综合评估的MTOPSIS-GRA模型。首先,通过10根T型梁的火灾高温试验、振动测试和静载试验,获取其热力学特性衰变等信息,并与ANSYS数值仿真计算对比分析；其次,构建一套由灾后表观特征、表面最高温度、持续受火时间、承载力折减、刚度折减、基频衰减等组成的RC梁火灾损伤评估指标体系,初步确定评估指标体系的量化分级标准,以组合形式优化层次分析法和熵权法确定的指标权重,引入改进的接近理想解法(modified technique for order preference by similarity to ideal solution, MTOPSIS)与灰色关联度分析(grey relational analysis, GRA),建立RC梁火灾损伤综合评估的MTOPSIS-GRA模型；最后,将该方法应用于火灾后RC梁损伤评估,并与火灾后建筑结构鉴定标准方法、试验实际情况进行对比分析。结果表明,本文方法评估结果与标准评估结果基本一致,但其能够较全面准确的评估结构损伤状态,为后续损伤评估及加固修复提供可靠依据。
In order to comprehensively and accurately evaluate reinforced-concrete-beam fire-damage state, with combination of various information from fire hazard tests and numerical simulations, MTOPSIS-GRA model for comprehensive assessment of RC-beam fire-damage state was successfully proposed. Firstly, through a series of fire high-temperature tests, vibration tests and static-load tests upon totally 10 T-shape beams, corresponding key data, such as thermodynamic-decay characteristics, was further achieved. And based on that, the above information was better compared with the results achieved by ANSYS numerical simulations and calculations. Secondly, one set of assessment-index systems for RC-beam fire-damage state, composed of post-disaster apparent characteristics, maximum surface temperature, fire duration, bearing capacity reduction, stiffness reduction and fundamental frequency attenuation and other indexes, was constructed. Besides that, a comprehensive quantitative-classification standard targeting to the said assessment-index system was preliminarily determined. And by means of further optimizing assessment-index weights achieved by AnalyticSHierarchySProcess and Entropy-weight Method with combination forms, as well as introducing and improving Modified Technique for Order Preference by Similarity to Ideal Solution (MTOPSIS) and GreySRelationalSAnalysis (GRA), one MTOPSIS model applicable to comprehensive assessment of RC-beam. fire-damage state was established. Finally, by applying this way into practical post-disaster RC-beam fire-damage assessments and conducting necessary comparative analyses between the current post-disaster building-structure appraisal standards ways and actual results achieved by a large number of experiments, it turns out that the assessment results achieved therein are basically consistent with the standardized assessment ones. However, the former can more comprehensively and accurately assess whole-structure fire-damage state for offering reliable base for subsequent damage assessments, reinforcements and repairs.