橋梁這類基礎(chǔ)設(shè)施在城市生活中起著重要的作用,并且在其運(yùn)營期內(nèi)會(huì)受到外部各種環(huán)境和荷載的作用及影響。結(jié)構(gòu)健康監(jiān)測(Structural Health Monitoring,簡稱:SHM)就是一種對(duì)結(jié)構(gòu)進(jìn)行各種物理參數(shù)和響應(yīng)的監(jiān)測分析、并給出預(yù)警控制及結(jié)構(gòu)安全性評(píng)估的工具。在結(jié)構(gòu)健康監(jiān)測中,有時(shí)要準(zhǔn)確檢測施加在橋上的荷載及時(shí)間歷程是不可能的,例如,有著高流量交通的高速公路橋梁。當(dāng)作用在結(jié)構(gòu)上完整的激勵(lì)不可知時(shí),可以使用基于純輸出的結(jié)構(gòu)振動(dòng)響應(yīng)信號(hào)進(jìn)行模態(tài)識(shí)別和損傷探測。本文提出了三種基于純輸出結(jié)構(gòu)振動(dòng)響應(yīng)信號(hào)進(jìn)行損傷檢測的方法,其原理是基于結(jié)構(gòu)的加速度數(shù)據(jù)或其他響應(yīng)進(jìn)行信號(hào)處理和分析來確定結(jié)構(gòu)的損傷及損傷定位。這些加速度數(shù)據(jù)可以從數(shù)值模型或?qū)嶋H橋梁測試工作中獲得。由于加速度計(jì)非常便宜且易于實(shí)施,故采用這三種方法進(jìn)行損傷識(shí)別可以大大降低結(jié)構(gòu)健康監(jiān)測的成本和時(shí)間。第一種方法為移動(dòng)平均濾波器法(MAF),它是一種基于純輸出振動(dòng)信號(hào)且無需初始完好狀態(tài)或基準(zhǔn)的損傷識(shí)別方法,可用于在移動(dòng)載荷下通過測定結(jié)構(gòu)的動(dòng)力響應(yīng)輸出從而定位鋼梁中的損傷。MAF是一種基于簡單濾波器內(nèi)核(矩形形狀)的卷積方法,其主要通...

【文章頁數(shù)】：156 頁

【學(xué)位級(jí)別】：博士

【文章目錄】：
致謝
摘要
Abstract
1 Introduction
    1.1 Background and motivation of research
    1.2 Outline of research
2 Literature reviews
    2.1 The concept of damage detection
    2.2 Different techniques used in damage detection
        2.2.1 Frequency based damage detection methods
        2.2.2 Mode shapes based and mode shape curvatures based damage detection methods
        2.2.3 Dynamic measured flexibility based damage detection method
        2.2.4 Model updating based damage detection method
        2.2.5 Signal processing based damage detection methods
    2.3 Operational modal analysis (Output-only analysis)
    2.4 Damage detection without using modal parameters
    2.5 Signal correction
    2.6 Conclusions
3 Theory and methodology of moving average filter based SHM
    3.1 introduction
    3.2 Moving average filters
    3.3 Primary FE models of simply supported beam
        3.3.1 General definitions required in ABAQUS software
        3.3.2 Defining damage at numerical model
    3.4 Validation of moving average filter based damage detection method
        3.4.1 Locating the damage
        3.4.2 Predicting the baseline
        3.4.3 Effect of velocity of moving load
        3.4.4 Multiple damage scenarios
    3.5 Why the MAF-based method is working?
    3.6 Conclusions
4 Damage detection in simply supported steel beam under moving load: Experimental test
    4.1 Introduction
    4.2 Experimental model
    4.3 Sensor assessment and signal correction methods
    4.4 Results and discussion
    4.5 Conclusions
5 Theory and methodology of RD technique based SHM
    5.1 Introduction
    5.2 Random Decrement techniques
    5.3 Laboratory model of simply supported beam
    5.4 Results and discussion
        5.4.1 Primary data of simply supported beam
        5.4.2 Normalizing the Arias intensity along the structure
        5.4.3 Locating damage in simply supported beam
    5.5 Conclusions
6 Damage detection in a tied-arch bridge under moving load: Experimental test
    6.1 Introduction
    6.2 Experimental model
    6.3 Sensor assessment and signal correction methods
    6.4 Results and discussion
        6.4.1 Primary data of the tied-arch bridge
        6.4.2 Normalizing the Arias intensity along the structure
        6.4.3 Locating the connection loss in the cables at the tied-arch bridge
        6.4.4 Detecting small damage ratios in laboratory models
    6.5 Conclusions
7 Damage detection of the tied-arch bridge under seismic load (numerical analysis)
    7.1 Introduction
    7.2 Selecting the seismic events
    7.3 Numerical simulation of the tied-arch bridge
        7.3.1 Preliminary numerical model
        7.3.2 Preliminary results of the tied-arch bridge under dead load
        7.3.3 Applying the seismic load
    7.4 Modal properties of tied-arch bridge using ARTeMIS
        7.4.1 Preliminary results of dynamic seismic analysis
        7.4.2 Determining the natural frequencies of the tied-arch bridge
    7.5 Damage detection of the tied-arch bridge
        7.5.1 Normalizing factor
        7.5.2 Locating the damage under seismic load
    7.6 Discussion
        7.6.1 Effect of damage on the natural frequencies
        7.6.2 Using band-pass filtering according to other natural frequencies
    7.7 Conclusions
8 Conclusions and Outlook
    8.1 Conclusions
    8.2 Innovation points
    8.3 Outlook
References
Appendix 1: MATLAB Codes for Random Decrement Technique
Appendix 2: Details of the experimental test procedure of the tied-arch bridge
Appendix 3: SeismoSignal Guidance with an example
Appendix 4: ARTeMIS Guidance with an example
作者簡歷及在學(xué)期間所取得的科研成果
    1. Resume of the author
    2. The Research Results and Published Papers



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