基于压电陶瓷传感器宽频响应的结构损伤识别

发布时间：2018-04-09 00:32

  本文选题：土木工程　切入点：结构健康监测　出处：《大连理工大学》2015年博士论文

【摘要】：压电陶瓷(如锆钛酸铅,Pb-based Lanthanumdoped Zirconate Titanates,简称PZT)材料,因其造价低廉,以及频率响应范围宽等优点,在土木工程结构健康监测领域应用前景广泛。然而,尽管压电陶瓷传感器具有很宽的频率响应范围,应用压电陶瓷传感器的结构损伤识别研究,往往只应用到某一部分频率范围的传感器信号以达到单一的监测目的。压电陶瓷传感器在宽频响应下的动态特性及多功能监测等方面的研究,有待进一步发展。本文进行了基于压电陶瓷传感器在300kHz内宽频响应的结构损伤识别技术研究,主要内容如下：(1)针对粘贴式压电陶瓷传感器与结构的耦合体系,提出了一种“压电陶瓷—粘结层—被测结构”考虑层状介质剪切应变传递的动态力学模型。分析了驱动频率对压电陶瓷传感器应变传递特性的影响。并利用该模型,分别分析了压电陶瓷片的厚度、粘结层材料、粘结层厚度对传感器动态特性的影响,所提模型的有效性用ANSYS有限元分析和试验加以验证。(2)分析了宽频激励下,嵌入式压电陶瓷传感器的动态性能,提出了一种“保护层—防水层—压电陶瓷”结构的动态力学模型。分析了驱动频率对压电陶瓷极化方向动态应力传递特性的影响,并分析了保护层、防水层的材料和厚度、压电陶瓷片的厚度对传感器动态性能的影响。利用ANSYS有限元分析和试验验证了分析的正确性。(3)分析了压电陶瓷传感器低频响应“拍”信号的形成机理,通过旋转矢量法分析了结构的阻尼效应、荷载冲击方向、传感器位置对“拍”信号的影响。根据压电陶瓷传感器“拍”信号,提出了一种荷载冲击方向的识别方法,并通过悬臂钢柱的冲击试验验证了方法的有效性。(4)提出了一种应用压电陶瓷传感器低频应力响应的结构损伤识别方法,即基于互相关函数幅值和支持向量机的损伤识别方法,该方法仅需要压电陶瓷传感器测得的结构应力响应信号,且适用于任意荷载激励。利用IASC-ASCE Benchmark模型的数值验证和桁架结构模型的损伤识别试验,验证了方法的有效性。(5)基于压电陶瓷传感器宽频响应特性,提出了一种应用压电陶瓷传感器低频的结构振动响应信号和高频声发射信号的多功能监测方法。以钢筋混凝土梁动态弯曲破坏试验为例,分析了压电陶瓷传感器在混凝土构件中的多功能监测；进行了钢筋混凝土框剪结构模型的地震破坏监测试验,利用压电陶瓷传感器的多功能性,同时分析了结构的动态特性和局部损伤情况。
[Abstract]:Piezoelectric ceramics (such as lead zirconate titanate Pb-based Lanthanumdoped Zirconate Titanatesfor short) are widely used in the field of civil engineering structural health monitoring due to their low cost and wide range of frequency response.However, although piezoelectric ceramic sensors have a wide frequency response range, the structural damage identification of piezoelectric ceramic sensors is often applied to a certain frequency range of sensor signals to achieve a single monitoring purpose.The dynamic characteristics and multifunctional monitoring of piezoelectric ceramic sensors in broadband response need further development.In this paper, the structure damage identification technology based on the broadband response of piezoelectric ceramic sensor in 300kHz is studied. The main contents are as follows: 1) the coupling system between the sticker piezoelectric ceramic sensor and the structure.A dynamic mechanical model considering shear strain transfer in layered media is proposed.The effect of driving frequency on the strain transfer characteristics of piezoelectric ceramic sensor is analyzed.Using this model, the effects of the thickness of piezoelectric ceramic plate, the bonding layer material and the thickness of bonding layer on the dynamic characteristics of the sensor are analyzed, respectively. The validity of the proposed model is verified by ANSYS finite element analysis and experiments.In this paper, a dynamic mechanical model of "protective layer-waterproof layer-piezoelectric ceramic" structure is proposed for the dynamic performance of embedded piezoelectric ceramic sensor.The effect of driving frequency on the dynamic stress transfer characteristics in polarization direction of piezoelectric ceramics is analyzed. The influence of the material and thickness of the protective layer, the waterproof layer and the thickness of the piezoelectric ceramic plate on the dynamic performance of the sensor is analyzed.The correctness of the analysis is verified by ANSYS finite element analysis and test. The forming mechanism of the "beat" signal of piezoelectric ceramic sensor is analyzed. The damping effect and the direction of load impact of the structure are analyzed by rotating vector method.The effect of sensor position on the "beat" signal.According to the "beat" signal of piezoelectric ceramic sensor, a method for identifying the direction of load impact is proposed.The effectiveness of the method is verified by the impact test of cantilever steel columns. (4) A structural damage identification method based on the amplitude of cross-correlation function and support vector machine is proposed, which applies the low-frequency stress response of piezoelectric ceramic sensor.This method only needs the structural stress response signal measured by piezoelectric ceramic sensor and is suitable for arbitrary load excitation.The validity of the method is verified by the numerical verification of the IASC-ASCE Benchmark model and the damage identification test of the truss structure model. The method is based on the broadband response characteristics of the piezoelectric ceramic sensor.A multifunctional monitoring method for structural vibration response signals and high frequency acoustic emission signals using piezoelectric ceramic sensors at low frequency is presented.Taking the dynamic bending failure test of reinforced concrete beam as an example, the multi-function monitoring of piezoelectric ceramic sensor in concrete member is analyzed, and the seismic failure monitoring test of reinforced concrete frame-shear structure model is carried out.The multifunctional piezoelectric ceramic sensor is used to analyze the dynamic characteristics and local damage of the structure.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU317
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本文编号：1724077