整体钢框架结构中连续板热振动特性试验  

Experiment of Thermal Vibration Characteristics of Continuous Panels in Whole Steel-framed Structure

作　　者：李兵[1] 董毓利[2] 王勇[3] 娄永杰 

机构地区：[1]海南大学土木建筑工程学院,海南海口570228 [2]华侨大学土木工程学院,福建厦门361000 [3]中国矿业大学力学与建筑工程学院,江苏徐州221116 [4]中信建筑设计研究总院有限公司,湖北武汉430014

出　　处：《建筑科学与工程学报》2016年第3期78-85,共8页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(51178143);海南省自然科学基金项目(20165189);海南大学科研启动基金项目(kyqd1566)

摘　　要：采用自制火灾试验炉对整体钢框架中4个钢筋混凝土连续板格和2个组合钢梁的热振动特性进行了试验研究。采集了构件受火时的加速度信号并尝试利用希尔伯特变换提取主频率,并对加速度信号进行时域分析和频域分析。时域分析结果表明:加速度信号强度与边界约束和裂缝开展密切相关,约束越强,振动信号越弱;主裂缝开展导致板格加速度信号发生突变,而组合钢梁的信号突变则受到应力重分布和主裂缝开展的影响;升温阶段加速度曲线可分为3个阶段,前期和后期振动幅值很小,中期振动幅值较大且伴随较多的信号突变。频域分析结果表明:受火时主频率变化显著并呈现下降的趋势,但频率改变只能反映裂缝开展程度,不能确定裂缝位置,且频率变化近似与挠度的变化过程相对应;通过振动特征分析可以有效监测楼板的变形、裂缝开展等受火行为。Thermal vibration characteristics of four continuous reinforced concrete panels and two composite beams in a whole steel-framed structure were tested by using the self-made fire furnace.The acceleration signals of the building components during the fire were collected and Hilbert transform（HT）was adopted to extract instantaneous principal frequencies.Time-domain analysis and frequency-domain analysis of acceleration signals were performed.Time-domain analysis shows that acceleration signal intensity has important relationship with boundary constraints and crack propagation.When the constraints are stronger,the signal intensity is weaker.Moreover,main crack propagation leads to mutations of acceleration signals of heated panels,but for composite beams,stress redistribution and main crack propagation stimulate mutations of acceleration signals.During the heat-up stage,acceleration curves can be dividedinto three stages.Acceleration signals are relatively low during the early and late stages but strong during the medium stage with more signal mutations are detected.Frequency-domain analysis shows that principal frequencies change dramatically and present a downward trend during the heat-up stage,but the changes only reflect the level of crack propagation and cannot identify damage locations.In addition,the frequency changes correspond approximately to deflection changes in sequence.Therefore through analysis of vibration characteristics,the fire behavior including deformation and cracks can be monitored.

关 键 词：整体钢框架 连续板 热振动特性 希尔伯特变换 主频率 

分 类 号：TU375.4[建筑科学—结构工程]