基于压电陶瓷的钢管混凝土剖柱的损伤监测研究

发布时间：2018-06-18 09:39

本文选题：钢管混凝土剖柱 + 压电陶瓷　；参考：《湖南大学》2015年硕士论文

【摘要】：钢管混凝土结构凭借其力学性能优越、施工速度快,耗材少等优点在超高层及大跨度桥梁结构中应用日益广泛。钢管与其核心混凝土界面的有效约束是构件发挥其力学性能优势的关键,钢管内壁与核心混凝土的界面剥离将消弱约束效应进而对构件的承载力和延性等力学性能带来负面的影响。因此,对钢管内壁与核心混凝土的界面粘结状况进行损伤监测和评估显得尤为重要。但是,由于界面剥离损伤的不可见性,我国目前超声波检测混凝土质量缺陷规程中没有针对界面剥离提出相应的检测方法。为排除应力波的直接沿着钢管外壁传播的干扰,本文设计了钢管混凝土剖柱,并提出了一种基于压电陶瓷波动分析法的钢管混凝土剖柱的界面剥离损伤监测方法,并且将该方法应用于钢管混凝土圆柱构件的性能检测。其具体工作包括以下几个方面:(1)针对压电陶瓷的特性详细介绍了压电功能元的制作工艺,并对其进行静态和动态性能的试验研究及标定试验。结果表明该试验系统具有良好的静态和动态响应特性,动态线性度好。(2)设计了一根带界面剥离损伤的钢管凝土剖柱的构件模型,在模型中埋入嵌入式压电功能元作为驱动器和传感器。分析主动不同激励信号下的测量信号,针对正弦信号、扫频信号下的小波包能量等特征参量定义了相应的损伤指标。结果表明,提出基于压电测量信号的损伤指标有效地识别了钢管混凝土剖柱构件的界面剥离损伤。(3)提出了基于波动法的频响函数损伤判定方法,通过力锤激励产生脉冲信号,外贴的压电功能元作为传感器。通过对压电陶瓷监测的波动信号在合适的频段上的频响函数分析实现了钢管混凝土剖柱构件的界面剥离损伤监测。(4)在小波包分析和频响函数分析的界面剥离损伤判定方法的基础之上,利用波动法对带自然界面剥离缺陷和人工模拟界面剥离的钢管混凝土圆柱进行监测,进一步验证了基于压电材料测量的钢管混凝土结构界面剥离损伤的可行性和敏感性。
[Abstract]:Concrete-filled steel tube (CFST) structure has been widely used in super-tall and long-span bridge structures due to its advantages of superior mechanical properties, fast construction speed and less consumable materials. The effective constraint of the interface between the steel tube and its core concrete is the key to give full play to the advantages of the mechanical properties of the members. The interface exfoliation between the inner wall of steel tube and the core concrete will weaken the constraint effect and bring negative influence on the mechanical properties such as the bearing capacity and ductility of the members. Therefore, it is very important to monitor and evaluate the interfacial bond between the inner wall of steel tube and the core concrete. However, due to the invisibility of the interface debonding damage, there is no corresponding detection method for the interface stripping in the ultrasonic inspection rules for concrete quality defects in China. In order to eliminate the interference of the stress wave propagating directly along the outer wall of the steel tube, this paper designs a concrete filled steel tube column, and proposes a method to monitor the damage of the interface stripping of the steel tube concrete column based on the piezoelectric ceramic wave analysis method. The method is applied to test the performance of concrete-filled steel tubular members. The specific work includes the following aspects: 1) the fabrication process of piezoelectric functional unit is introduced in detail according to the characteristics of piezoelectric ceramics, and the static and dynamic properties of piezoelectric functional unit are tested and calibrated. The results show that the test system has good static and dynamic response characteristics, and the dynamic linearity is good. Embedded piezoelectric function elements are embedded in the model as actuators and sensors. The measurement signals under different active excitation signals are analyzed and the corresponding damage indexes are defined for the characteristic parameters such as wavelet packet energy under sinusoidal signals and sweep signals. The results show that the damage index based on piezoelectric measurement signal can effectively identify the interface debonding damage of concrete filled steel tube (CFST) members. A frequency response function damage determination method based on wave method is proposed. The pulse signal is generated by force hammer excitation. An external piezoelectric functional element is used as a sensor. By analyzing the frequency response function of the wave signal of piezoelectric ceramic monitoring in the appropriate frequency band, the interface stripping damage monitoring of concrete-filled steel tubular members is realized. 4) the interface stripping damage in wavelet packet analysis and frequency response function analysis is realized. Based on the decision method, The wave method is used to monitor the concrete filled steel tube (CFST) columns with natural interface debonding defects and artificial interface debonding, which further verifies the feasibility and sensitivity of the interface debonding damage of CFST structures based on piezoelectric material measurement.
【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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