钢筋混凝土梁火灾损伤的多元信息融合模型

Multi-information fusion model for fire damage of reinforced concrete beam

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,提出钢筋混凝土梁(RC梁)火灾损伤综合评估的MTOPSIS-GRA模型。通过10根T形梁的火灾高温试验、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数值仿真计算结果对比;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、基频折减等组成的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,该方法评估结果与标准评估结果基本一致,但能够较全面准确地评估结构损伤状态。

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 reduction 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 Analytic Hierarchy Process 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 Grey Relational Analysis(GRA),one MTOPSIS-GRA model applicable to comprehensive assessment of RC-beam fire-damage state has been determined.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 standard method 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.