Rail and bridge infrastructure assets are critical elements of Canada’s transportation network and their continued efficient and safe operation is necessary to ensure the nation’s economic livelihood. Monitoring technologies that can detect changes in performance as well as precursors to failure are an important element of ensuring this efficient and safe operation. Digital Image Correlation (DIC) is a monitoring technology that has the potential to provide critical data for infrastructure assessment and to replace various conventional sensors with one integrated monitoring solution. In this research, the accuracy of DIC is evaluated using numerical, laboratory and field-based experiments. The sources of error of particular relevance to dynamic measurement using DIC are identified as (i) bias error in the sub-pixel interpolation scheme, (ii) the ratio of sample rate to the frequency of the signal being monitoring and (iii) the signal to noise ratio. It is also shown that the chosen sub-pixel interpolation scheme can greatly affect the accuracy of dynamic measurements. The use of DIC was investigated for field monitoring of both horizontal and vertical railway displacements at sites with good and poor subgrade conditions under dynamic train loading. It is shown that there is a significant benefit to using an absolute displacement measurement system rather than a relative displacement measurement system as the former can capture irrecoverable rail displacements in both the vertical and horizontal directions. Finally, DIC was also used for field monitoring of a very stiff reinforced concrete bridge during static and dynamic load tests. It is shown that when using DIC for deflection monitoring, corrections may have to be made to compensate for errors such as camera jitter and drift to acquire the most accurate results. Two potential correction methods were the use of a fixed reference point and generating composite images using average pixel intensity values from multiple images. It was found that using a fixed reference point was the optimal choice in this bridge test. It is concluded that DIC can be used as an effective displacement measurement tool for bridge assessment because it shows excellent correlation with linear potentiometer results and it can allow measurements to be taken without having to close the bridge. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-09-26 15:40:16.744

The primary aim of this dissertation is to examine the hermeneutical foundation, the biblical basis, the historical principle, and then to formulate a four-bridge application paradigm based on four distinguished processes--exegetical, doctrinal, homiletical, and transformational--aiming at transforming the lives of listeners for the glory of God. Chapter 1 analyzes the indispensability of a well-balanced hermeneutical application paradigm by arguing the relationship between hermeneutics and application, by reexamining application paradigms and bridge-building models, and by refocusing the four bridge paradigm. Chapter 2 examines the sermons of biblical prototypes--Moses, Ezra, the Minor Prophets, and Paul--and their features of application paradigms by means of a paradigmatic analyses rather than an exhaustive one. This chapter thoroughly explores Paul's sermons in his epistles, his preaching in Acts, and his hermeneutical bridge-building paradigm. The essential characteristics of these biblical models lead to a four-bridge life-changing application paradigm. Chapter 3 investigates four exemplary historical models--John Chrysostom, John Calvin, Jonathan Edwards, and John Broadus--and examines their illustrative sermons to identify their indispensable principles of application paradigms and to apply these historical facets for formulating a contemporized application paradigm. Four models provide a historical validation to formulate a legitimate life-changing application paradigm. Chapter 4 proposes a four-bridge application paradigm rooted in hermeneutical, biblical prototypes and historical models. The chapter systemizes (1) an exegetical bridge for discerning the aim of author-intended signification and the criteria for transferring universal principles of application (2) a doctrinal bridge for examining seven master keys to unlock the universal principles of ethical application, (3) a homiletical bridge for identifying a variety of relevance categories, legitimate methodologies of audience exegesis and adaptation, and an appropriate degree of transfer, and (4) a Spirit-led transformational bridge that is legitimate to change the lives of listeners. Chapter 5 concludes that contemporary preachers, as bridge-builders, need to seek a life-transforming application paradigm by utilizing the exegetical bridge, the doctrinal bridge, the homiletical bridge and the Spirit-led transformational bridge.

Master of Science / Department of Civil Engineering / Robert J. Peterman / With aging and deterioration of bridges, evaluation of existing conditions of their structural elements becomes vital to engineers and public officials when deciding how to repair or replace the structures. The ability to obtain necessary information on these conditions is often expensive and time consuming, especially for concrete bridges where the reinforcement is not available for inspection. Employing the surface-strain relief method could allow for accurate evaluation of aged or damaged prestressed members. The surface-strain relief method was developed to measure initial or pre-existing strains in a concrete member. It involves relieving the strain in the member and measuring the change in strain. Two methods were tested—one used a linear electrical-resistance strain gage and a three-inch-diameter diamond concrete core bit to cut around the gage, and the second method used a laser-speckle imaging device and a diamond cutting wheel to create notches perpendicular to the axis of maximum strain. Both methods measured the change in strain and related it to within 10 percent of the actual fse. The method of cutting notches and the laser-speckle imaging device provided a simpler method to be implemented in the field, while the coring method achieved a higher level of accuracy and precision.

Latest advancements in software have become an indispensable tool in structural analysis. The main goal of this thesis is to examine dynamic responses of bridges in seismic activity with the help of such tool as CSi Bridge. Therefore, throughout this study, a prestressed concrete bridge model will be thoroughly designed. In the first section, the required materials and structural components will be introduced. The following section will cover calculations required for modeling. The actual modeling of the structure will be carried out in Section 3. In Section 4, the set of required analysis for seismic design such as modal, pushover and response spectrum will be conducted. Lastly, in Section 5, analysis results will be evaluated. Thus, by examining the entire model, its construction, materials used, provided properties and conditions such as location on earth, seismic magnitude, it will be determined whether the design is sufficient and acceptable or not.

<p>In recent years, there have been a number of truck fires involving bridges with concrete components. If the fire burns for a significant period of time, the structural integrity of concrete components could be damaged due to fire. Research-based guidance for evaluating the level of fire damage is currently unavailable and would be beneficial for post-fire bridge inspectors. </p> <p>This research project focused on evaluating the effects of fire induced damage on concrete bridge deck elements. In order to achieve this goal, a series of controlled heating experiments and material analysis were conducted. Two concrete bridge deck specimens from the I-469 bridge over Feighner Road were heated for different time durations (40 - 80 min.) following the ISO-834 temperature-time curve. The deck specimens were cooled naturally after the specific heating durations. The temperature profiles through the depth of deck specimens were measured during heating and cooling. After testing, concrete samples were taken from the deck specimens for material analysis. Different types of material tests were conducted on samples taken from the undamaged and damaged deck specimens. The material test results were used to evaluate the effects of fire induced damage on the concrete microstructure, and to correlate the microstructure degradation with the through-depth temperature profiles of deck specimens. </p> <p>From the experimental results, several critical parameters that can affected by fire temperature and duration were discussed: (i) through-depth temperature profiles of deck specimens, (ii) cracks on the exposed surface of deck specimens, (iii) color changes of deck specimens, (iv) microstructure of heated concrete samples, (v) content of calcium hydroxide in fire damaged concrete samples at various depths. Based on the results from heating experiments and observations from material analysis, recommendations and guidance for evaluating concrete decks subjected to realistic fire scenarios are provided to assist bridge inspectors.</p>

<p>Obtaining a greater understanding of photo-induced electron-transfer (PET) processes is key to synthesizing photovoltaic materials with enhanced efficiency. Gaining knowledge about the structure property relationship in photo-active donor-bridge-acceptor (<i>D-B-A</i>) dyads will help to optimize electronic and photoelectronic materials. Metal acetylide complexes have attracted increasing interest for their potential applications as building blocks for electronic and photoelectronic materials. Their unique υ(C≡C) (2000-2100 cm^-1) allows for selective excitation, making them an appealing target for attenuating PET processes across a metal acetylide backbone. The following topics will be discussed: i.) an overview of M(cyclam′) alkynyl chemistry, where M = Cr, Fe, Co, or Ni, with a focus on reactivity and spectroscopy, ii.) selective synthesis of dissymmetric species, utilizing a Co^III(cyclam) (1,4,8,11-tetraazacyclotetradecane) alkynyl bridge, iii) synthesis and characterization of metal alkynyl <i>D-B-A</i> dyads <i>trans- </i>[R'₂N-4-C₆H₄C₂-Co^III(cyclam)-C_n-NAP^R]⁺(n = 2 or 4), where the chromophore acceptor is NAP^iPr (<i>N</i>-isopropyl-1,8-napthalimide) and the putative donor is -C₆H₄-4-NR'₂ (R' = Me or Ph-4-OMe), iv.) design and synthesis of <i>D-B-A</i> derivatives, alter NAP^R (R = mesityl, methyl, 1-ethylpropyl, 2-ethylhexyl, or octyl) to tune reactivity and crystallinity, v.) electronic and spectroscopic influence the bridging center on <i>A</i>, and vi.) effect of η² coordination of MX₂ (MX₂ = CuCl₂ or Ag(NO₃)₂) to the alkyne bridge on electron transfer. </p>

O presente trabalho visa estabelecer uma metodologia alternativa para o levantamento dos principais transitórios elétricos sofridos por excitatrizes brushless, decorrentes de transitórios ocorridos na armadura do gerador principal. O método consiste no cálculo, a partir de dados de projeto, dos parâmetros que compõem os circuitos equivalentes do gerador principal e da excitatriz, seguido de simulações, em ambiente PSIM®, dos piores casos de transitórios de tensão e corrente sofridos pela armadura do gerador principal, como curtos-circuitos monofásicos, bifásicos e trifásicos, operação assíncrona do gerador principal e sincronização com defasagem entre as tensões do gerador e da rede. Em cada caso, monitoram-se as tensões e correntes resultantes nos diodos da ponte retificadora rotativa. Resultados simulados e experimentais são comparados. / This study aims to establish an alternative methodology for determining the main transients on brushless exciters due to transients in the main generator armature. The method consists in calculating, from design data, the parameters of the equivalent circuits of the main generator and the exciter, followed by simulations, with the software PSIM®, of the worst voltage and current transient cases in the main generator armature, like single-phase, dual-phase and three-phase short circuits, asynchronous running of the main generator and out of phase synchronization. In each case the currents and voltages of the rotative bridge diodes were monitored. Simulation and experimental results are compared.

Este trabalho apresenta o estudo teórico e experimental do comportamento de placas ortótropas treliçadas protendidas transversalmente, sendo as ligações das barras das treliças com conector de chapas com dentes estampados (CDE), para aplicação em pontes de madeira observando as principais características do sistema como: avaliação do elemento estrutural e do modelo estrutural para verificação dos deslocamentos da placa. Para esta finalidade foram determinadas as propriedades dos materiais, elementos estruturais e níveis de protensão da placa. A avaliação das propriedades elásticas da placa foi realizada utilizando dois modelos numéricos, sendo um baseado no método dos elementos finitos e o segundo em séries de Levy-Nadai. A aferição do modelo proposto foi realizado com o ensaio de um protótipo em escala real. Os resultados indicaram que a placa tem um ótimo comportamento para a utilização em pontes apresentando elevada rigidez e baixo consumo de madeira, e que os modelos propostos apresentaram-se consistentes para aplicação nos sistemas de placas ortótropas treliçadas com ligações de chapas com dentes estampados / This work aim to the theoretical and experimental study of the behaviour of orthotropic stress-laminated truss plate for timber bridges construction. To this purpose the material properties, structural elements, conections and prestress level were analysed. Two numeric models were used in order to avaliate the plate elastic properties, based on the finite elements analysis method and in Levy-Nadai series. The theorical model calibration was made with the results obtained in a full-scale prototype. The results indicated that the plate behavior was efficiency for the use in bridges with high stiffness and wood low consumption, and that the proposed numeric models was consistent for application in ortrotropic stress-laminated truss plate systems with metal-plate-connected

Completely inorganic nanoscale clusters play an essential role in many aspects of inorganic chemistry, materials chemistry, and geochemistry. The underlying dynamic behavior of these species in solution defines how and why they make successful thin film precursors as well as exist naturally in the environment. There have been a limited number of previous solution studies involving inorganic nanoscale clusters due to the lack of spectroscopic handles and availability of analytical techniques. This dissertation outlines the available and appropriate characterization techniques needed for identifying and studying inorganic nanoscale species and then uses proton Nuclear Magnetic Resonance (1H-NMR) and Diffusion Ordered Spectroscopy (DOSY) to fully characterize the Ga13-xInx(µ3-OH)6(µ-OH)18(H2O)24(NO3)15 (0 ≤ x ≤ 6) cluster series in solution. This research lays a foundation for a multitude of future studies on the dynamic behavior of these species that was previously unachievable. This dissertation includes previously published and unpublished co-authored material.

Civil infrastructure are critical elements to a society’s welfare and economic thriving. Understanding their behaviour and monitoring their serviceability are relevant challenges of Structural Health Monitoring (SHM). Despite the impressive improvement of miniaturisation, standardisation and diversity of monitoring systems, the ability to interpret data has registered a much slower progression across years. The underlying causes for such disparity are the overall complexity of the proposed challenge, and the inherent errors and lack of information associated with it. Overall, it is necessary to appropriately quantify the uncertainties which undermine the SHM concept. This thesis proposes an enhanced modular Bayesian framework (MBA) for structural identification (st-id) and measurement system design (MSD). The framework is hybrid, in the sense that it uses a physics-based model, and Gaussian processes (mrGp) which are trained against data, for uncertainty quantification. The mrGp act as emulators of the model response surface and its model discrepancy, also quantifying observation error, parametric and interpolation uncertainty. Finally, this framework has been enhanced with the Metropolis–Hastings for multiple parameters st-id. In contrast to other probabilistic frameworks, the MBA allows to estimate structural parameters (which reflect a performance of interest) consistently with their physical interpretation, while highlighting patterns of a model’s discrepancy. The MBA performance can be substantially improved by considering multiple responses which are sensitive to the structural parameters. An extension of the MBA for MSD has been validated on a reduced-scale aluminium bridge subject to thermal expansion (supported at one end with springs and instrumented with strain gauges and thermocouples). A finite element (FE) model of the structure was used to obtain a semi-optimal sensor configuration for stid. Results indicate that 1) measuring responses which are sensitive to the structural parameters and are more directly related to model discrepancy, provide the best results for st-id; 2) prior knowledge of the model discrepancy is essential to capture the latter type of responses. Subsequently, an extension of the MBA for st-id was also applied for identification of the springs stiffness, and results indicate relative errors five times less than other state of the art Bayesian/deterministic methodologies. Finally, a first application to field data was performed, to calibrate a detailed FE model of the Tamar suspension bridge using long-term monitored data. Measurements of temperature, traffic, mid-span displacement and natural frequencies of the bridge, were used to identify the bridge’s main/stay cables initial strain and friction of its bearings. Validation of results suggests that the identified parameters agree more closely with the true structural behaviour of the bridge, with an error that is several orders of magnitude smaller than other probabilistic st-id approaches. Additionally, the MBA allowed to predicted model discrepancy functions to assess the predictive ability of the Tamar bridge FE model. It was found, that the model predicts more accurately the bridge mid-span displacements than its natural frequencies, and that the adopted traffic model is less able to simulate the bridge behaviour during periods of traffic jams. Future developments of the MBA framework include its extension and application for damage detection and MSD with multiple parameter identification.