基于压电陶瓷的钢管混凝土组合结构界面损伤监测研究

发布时间：2018-04-01 01:16

本文选题：钢管混凝土组合结构　切入点：界面剥离损伤　出处：《湖南大学》2015年硕士论文

【摘要】：钢管混凝土组合结构以其承载力高、抗震性能优越、延性好等诸多优良的性能,在高层及超高层建筑结构、桥梁结构及工业厂房中被广泛地采用。在实际工程施工过程中,由于钢管内部横隔板、水化热、混凝土的收缩徐变等各方面的影响,都可能使钢管内壁与混凝土粘结界面出现界面剥离损伤,从而影响钢管与混凝土共同协作能力,进而降低钢管混凝土组合结构的承载力与变形能力等性能,对其粘结状况进行监测十分具有实际意义。然而,钢管混凝土组合结构界面剥离损伤不易察觉,传统无损检测手段无法有效适用,使得检测十分棘手。本文在前人对基于压电智能材料结构健康监测与研究的背景下,进一步研究基于波动分析法的钢管混凝土组合结构界面剥离损伤监测的方法,在实验室设计一组分离式界面剥离损伤构件,并对其损伤进行识别,最后将实验室比例模型试验研究成果的基础上,开展了工程应用。具体工作如下:(1)详细地介绍了用于钢管混凝土构件界面剥离缺陷检测的压电功能元的制作与封装流程,对压电监测系统进行了动态和静态性能测试,并对压电功能元进行了标定。结果表明:该健康监测系统具有良好的动态与静态性能,标定后的压电功能元为后续的试验研究奠定了基础。(2)在实验室设计并制作了一组分离式界面剥离损伤钢管混凝土组合结构,将嵌入式压电功能元与外贴式压电陶瓷片安装在设计位置,共同组成健康监测系统的换能器对,利用波动分析法对预设的不同厚度与不同大的界面剥离类型损伤进行了识别。对输出信号进行了基于正弦信号的频域幅值、基于稳态正弦扫频信号的小波包能量及其能量谱、基于脉冲信号的传递函数研究,并提出了基于特征参量的损伤指标。结果表明:所采用的方法可以有效地识别出两种类型的损伤,证明了基于压电陶瓷的波动分析法对钢管混凝土构件界面剥离损伤识别方法可行而且有效。(3)基于稳态正弦扫频信号的小波包能量及其能量谱损伤判定方法,利用波动分析法对一实际超高层建筑进行了现场足尺比例的钢管混凝土框架柱界面性能监测。结果表明:该柱的小波包能量稳定,其能量离差系数在规定的范围内;其小波包能量谱差异值也较小,表明该钢管混凝土框架柱未出现明显的剥离损伤。
[Abstract]:Concrete-filled steel tube (CFST) composite structures are widely used in high-rise and super-high-rise building structures, bridge structures and industrial buildings because of their high bearing capacity, excellent seismic performance, good ductility and so on. Due to the influence of internal transverse partition, heat of hydration and shrinkage and creep of concrete, the interface between the inner wall of steel tube and the bond between concrete and steel tube may be stripped, thus affecting the cooperative ability of steel tube and concrete. So it is very meaningful to monitor the bond condition of CFST composite structure, but it is not easy to detect the damage at the interface of CFST composite structure. Traditional nondestructive testing methods can not be used effectively, which makes the detection very difficult. In this paper, based on piezoelectric smart material structure health monitoring and research background, This paper further studies the damage monitoring method of CFST composite structure interface based on wave analysis, designs a set of separated interface peeling damage components in laboratory, and identifies the damage of CFST composite structure. Finally, based on the experimental results of laboratory proportional model test, the engineering application is carried out. The specific work is as follows: 1) the fabrication and encapsulation process of piezoelectric functional units used for the inspection of interface stripping defects of concrete filled steel tube members are introduced in detail. The dynamic and static performance of the piezoelectric monitoring system is tested, and the piezoelectric functional unit is calibrated. The results show that the health monitoring system has good dynamic and static performance. The calibrated piezoelectric functional element lays the foundation for further experimental research. A set of separated interface debonded steel tubular concrete filled steel tube composite structures are designed and fabricated in laboratory. The embedded piezoelectric functional unit and the externally mounted piezoelectric ceramic chip are installed in the design position to form the transducer pair of the health monitoring system. The damage of different thickness and large interface is identified by wave analysis. The output signal is based on the frequency domain amplitude of sinusoidal signal, the wavelet packet energy and its energy spectrum of steady-state sinusoidal sweep frequency signal. Based on the transfer function of pulse signal, the damage index based on characteristic parameters is proposed. The results show that the proposed method can effectively identify two types of damage. It is proved that the wave analysis method based on piezoelectric ceramics is feasible and effective to identify the damage of concrete filled steel tube (CFST) interface. The wavelet packet energy and energy spectrum damage determination method based on steady-state sinusoidal sweep signal is proved. The interface performance of concrete filled steel tube (CFST) frame column in a practical super high-rise building is monitored by wave analysis method. The results show that the wavelet packet energy of the column is stable and the energy deviation coefficient is within the prescribed range. The difference of wavelet packet energy spectrum is also small, which indicates that there is no obvious delamination damage in the CFST frame column.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9;TU317

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