在過去的十年中,智能材料(例如壓壓材料(PZT))的使用為結(jié)構(gòu)健康動(dòng)動(dòng)提供了新的可能性,并加速了結(jié)構(gòu)識(shí)別和結(jié)構(gòu)健康動(dòng)動(dòng)(SHM)的發(fā)展。使用自感應(yīng)壓壓阻抗傳感器的機(jī)壓阻抗(EMI)技術(shù)取得了長足的進(jìn)步。該技術(shù)使用PZT貼片,貼到要?jiǎng)右暤慕Y(jié)構(gòu)中,提取機(jī)壓阻抗信息用于損傷檢動(dòng)。本文主要研究使用壓壓傳感器實(shí)時(shí)動(dòng)動(dòng)螺栓連接的松動(dòng)。壓壓換能器和主體結(jié)構(gòu)之間的機(jī)壓耦合效應(yīng)對(duì)局部損傷的敏感性被用于基于機(jī)壓(EM)阻抗的損傷檢動(dòng)技術(shù)。然而,當(dāng)這種技術(shù)應(yīng)用于大型結(jié)構(gòu),存在阻抗失配的問題,這是由于主體結(jié)構(gòu)的阻抗與PZT相比變得過大。為了解決這個(gè)問題,最近的研究人員開發(fā)了雙PZT配置。本文采用雙重PZT阻抗動(dòng)量技術(shù)用于動(dòng)視螺栓松動(dòng),螺栓松動(dòng)由兩個(gè)獨(dú)立的鋯鈦酸鉛(PZT)陶瓷片組成。本論文概述了機(jī)壓阻抗技術(shù)的背景理論,及其在螺栓連接的健康動(dòng)動(dòng)中的實(shí)現(xiàn)。重點(diǎn)研究了智能材料與螺栓連接系統(tǒng)相結(jié)合的簡化的機(jī)壓阻抗(EM)的一維模型,獲得螺栓預(yù)緊下的EM阻抗的特性。并通過有限元建模,研究了雙PZT動(dòng)動(dòng)下的螺栓松動(dòng)問題。通過對(duì)螺栓預(yù)緊條件下施加不同的動(dòng)態(tài)載荷(振動(dòng))進(jìn)行模擬,從粘結(jié)在螺栓接頭上的PZT(鋯鈦酸鉛)貼片的信...

【文章頁數(shù)】：75 頁

【學(xué)位級(jí)別】：碩士

【文章目錄】：
摘要
Abstract
Chapter1 Introduction
    1.1 Research Background
    1.2 Problem Statement
    1.3 Research Objectives
    1.4 Organization of thesis
    1.5 Literature Review
        1.5.1 Bolted Joint
        1.5.2 Bolted joints clamping force
        1.5.3 Bolted joints preload
    1.6 Bolted joints self loosening
        1.6.1 Vibration on a bolted joint
        1.6.2 Mechanism of self loosening of a bolted joint
        1.6.3 The factors influencing self loosening of a bolted joint
    1.7 Structural Health Monitoring Techniques
        1.7.1 Visual inspection method
        1.7.2 Low frequency vibration techniques
        1.7.3 Static response-based techniques
        1.7.4 Localized NDE techniques
        1.7.5 Smart system based techniques
    1.8 Summary
Chapter2 Electromechanical Impedance Method
    2.1 Introduction
    2.2 Theoretical Model of the EMI Technique
        2.2.1 1D Electromechanical impedance model
    2.3 Statistical Index
    2.4 Advantages and Limitations of EMI Technique
    2.5 Limitations of the EMI Technique
    2.6 Piezoelectric Material
        2.6.1 Brief History of piezo-ceramic transducers
        2.6.2 Properties of piezo-ceramic materials
    2.7 Method of Application
    2.8 Selection of Frequency Range
    2.9 Summary
Chapter3 Finite Element Analysis of Single Bolt Joint
    3.1 FE modeling
        3.1.1 Bolted joint Model definition
        3.1.2 Geometry and meshing
        3.1.3 Contact
        3.1.4 Boundary condition
        3.1.5 Modeling of PZT actuator and sensor
    3.2 Analysis of Bolted joint loosening on single bolt joint
        3.2.1 Transient analysis
    3.3 Bolt Loosening detection using PZT impedance signatures
        3.3.1 Harmonic Analysis
    3.4 Damage detection capability of the Piezo-voltage signal
    3.5 Bolt loosening quantification
    3.6 Summary
Chapter4 Steel Beam-Column Connection FEM Analyzes
    4.1 Bolted joint Model definition
    4.2 Transient analysis
    4.3 Harmonic analysis
    4.4 Statistical Index
    4.5 Frequency effect
    4.6 Temperature effect on impedance response
    4.7 Summary
Chapter5 Conclusion
    5.1 Conclusion in English
    5.2 Conclusion in Chinese
    5.3 Future Works
References
Acknowledgement



本文編號(hào)：3878771