Field Testing Implementation Of Vibration Based Damage Detection Techniques On A Scoured Coastal Bridge
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Vibration-based Techniques For Damage Detection And Localization In Engineering Structures
| Author | : Ali Salehzadeh Nobari |
| Publisher | : World Scientific |
| Total Pages | : 256 |
| Release | : 2018-05-04 |
| Genre | : Technology & Engineering |
| ISBN | : 178634498X |
In the oil and gas industries, large companies are endeavoring to find and utilize efficient structural health monitoring methods in order to reduce maintenance costs and time. Through an examination of the vibration-based techniques, this title addresses theoretical, computational and experimental methods used within this trend.By providing comprehensive and up-to-date coverage of established and emerging processes, this book enables the reader to draw their own conclusions about the field of vibration-controlled damage detection in comparison with other available techniques. The chapters offer a balance between laboratory and practical applications, in addition to detailed case studies, strengths and weakness are drawn from a broad spectrum of information.
Framework of Damage Detection in Vehicle-Bridge Coupled System
| Author | : Xuan Kong |
| Publisher | : LAP Lambert Academic Publishing |
| Total Pages | : 260 |
| Release | : 2013 |
| Genre | : |
| ISBN | : 9783659402692 |
Most vibration-based damage identification methods make use of measurements directly from bridge structures with attached sensors. The present study aimed to develop new methodologies to eventually detect bridge damages such as scour using the dynamic response of the vehicle. A framework of damage identification and an optimization method was developed first. Secondly, a new methodology using the transmissibility of vehicle and bridge responses was developed to detect bridge damages. Then, a tractor-trailer test system was designed to obtain reliable response and extract bridge modal properties from the dynamic response of moving vehicles. These developed methodologies were applied to detect scour damage from the response of bridge and/or vehicles. The scour effect on a single pile was studied and methods of scour damage detections were proposed. A monitoring system using fiber optic sensors was designed and tested in the laboratory and is being applied to a field bridge. Finally, the scour effect on the response of the entire bridge and the traveling vehicle was also investigated under the bridge-vehicle-wave interaction, which in turn was used to detect the bridge scour.
On the Spot Damage Detection Methodology for Highway Bridges
| Author | : Salam Rahmatalla |
| Publisher | : |
| Total Pages | : 72 |
| Release | : 2010 |
| Genre | : Bridges |
| ISBN | : |
The objective of this work was to develop a low-cost portable damage detection tool to assess and predict damage areas in highway bridges. The proposed tool was based on standard vibration-based damage identification (VBDI) techniques but was extended to a new approach based on operational traffic load. The methodology was tested using numerical simulations, laboratory experiments, and field testing.
Application of Vibration-based Techniques for Modal Identification and Damage Detection in Structures
| Author | : Chaewoon Lim |
| Publisher | : |
| Total Pages | : 152 |
| Release | : 2017 |
| Genre | : |
| ISBN | : |
All structures such as bridges, buildings and dams are deteriorated by environmental conditions like corrosion, earthquake and traffic after they are built. Therefore, vibration-based damage identification (VBDI) techniques have attracted attention to verify the safety and functionality of structures. Conventional damage identification techniques such as non-destructive evaluation (NDE) methods have many obstacles and are not practical to be implemented in order to detect damage. One of the main obstacles is that the conventional methods are focused on local structural damage and easily affected by measurement noise. Moreover, there are several uncertainties that restrict the successful application of the damage detection. On the other hand, vibration-based techniques can be used when the global vibration characteristics is available. To do this, it is required to perform modal identification, perform model updating, and detect local changes in a structure. The objectives of this study are: (a) to develop vibration-based techniques for modal identification by output-only information through the experimental and numerical study of bridges and frame structures; and (b) to study the VBDI techniques to perform model updating and damage detection using the changes in the dynamic characteristics of structures and determine their performance in practical structures. Two existing bridges, a Pre-stressed Concrete Bridge (PSCB) and a Steel Box Bridge (STB) tested earlier were used here as case studies and the data from the vibration test were used to verify modal identification using output-only information. In this study, two output-only methods, Frequency Domain Decomposition (FDD) and Stochastic Subspace Identification (SSI) were studied to compare the results from the vibration test. In addition to this, laboratory experiments on three-story steel frame were carried out to generate additional data for testing the system identification and model updating methods. Further, various damage scenarios were created in the frame to obtain the vibration signals corresponding to such conditions. The vibration data from the undamaged and damaged frame were used to study the performance of existing VBDI methods. Based on the above study, it is concluded that both FDD and SSI techniques provide accurate results for modal identification in the case of studied structures. FDD is relatively simpler, but it may miss some modal information when two modes are closer. However, in the cases studied here, the modes are quite apart from each other. Among many available VBDI methods, the matrix update method performs better than others when the measurement noise is small. Otherwise, data-driven models such as those based on Genetic Algorithm should be used.
Coastal Geohazard and Offshore Geotechnics
| Author | : Dong-Sheng Jeng |
| Publisher | : MDPI |
| Total Pages | : 348 |
| Release | : 2021-05-18 |
| Genre | : Technology & Engineering |
| ISBN | : 3036502742 |
With rapid developments being made in the exploration of marine resources, coastal geohazard and offshore geotechnics have attracted a great deal of attention from coastal geotechnical engineers, with significant progress being made in recent years. Due to the complicated nature of marine environmnets, there are numerous natural marine geohazard preset throughout the world’s marine areas, e.g., the South China Sea. In addition, damage to offshore infrastructure (e.g., monopiles, bridge piers, etc.) and their supporting installations (pipelines, power transmission cables, etc.) has occurred in the last decades. A better understanding of the fundamental mechanisms and soil behavior of the seabed in marine environments will help engineers in the design and planning processes of coastal geotechnical engineering projects. The purpose of this book is to present the recent advances made in the field of coastal geohazards and offshore geotechnics. The book will provide researchers with information reagrding the recent developments in the field, and possible future developments. The book is composed of eighteen papers, covering three main themes: (1) the mechanisms of fluid–seabed interactions and the instability associated with seabeds when they are under dynamic loading (papers 1–5); (2) evaluation of the stability of marine infrastructure, including pipelines (papers 6–8), piled foundation and bridge piers (papers 9–12), submarine tunnels (paper 13), and other supported foundations (paper 14); and (3) coastal geohazards, including submarine landslides and slope stability (papers 15–16) and other geohazard issues (papers 17–18). The editors hope that this book will functoin as a guide for researchers, scientists, and scholars, as well as practitioners of coastal and offshore engineering.
Structural Health Monitoring and Damage Evaluation of Full-scale Bridges Using Triaxial Geophones
| Author | : William Steven Ragland |
| Publisher | : |
| Total Pages | : 246 |
| Release | : 2009 |
| Genre | : |
| ISBN | : |
The purpose of this study was to evaluate the effectiveness of various vibration-based damage detection methods using triaxial vibration records obtained using inexpensive geophones during in-situ, full-scale, damaged bridge tests. Geophones are passive directional sensors and much cheaper than accelerometers which are typically used for structural vibration measurements. However, magnitude and phase errors associated with a geophone's output must be corrected for if they are implemented in bridge monitoring systems. This research discusses correction procedures for magnitude and phase errors associated with geophones. A simply supported beam was analyzed to verify that the correction procedures and modal parameter identification procedures used produced reliable results. A full-scale bridge test was also performed to further validate the correction and modal analysis procedures used. The results of the simple beam and full-scale bridge tests were validated using finite element modeling. Vibration-based damage detection relies on changes in the dynamic properties of a structure to detect damage. Only one other study was found that compares various vibration-based damage detection techniques using full-scale damaged bridge tests. Thus, a need remains for further comparison of vibration-based damage detection techniques using vibration data collected entirely on full-scale bridges. This study compares various vibration-based damage detection techniques using triaxial vibration records obtained during separate in-situ, full-scale, damaged bridge tests. Furthermore, the damage detection techniques are extended to three dimensions to evaluate three dimensional response of the bridge to damage. This is a unique aspect of the current research because no other three dimensional data sets obtained from in-situ, full-scale, damaged bridge tests have been reported in the literature. Finite element modeling is perhaps the most widely relied upon method of structural and mechanical analysis. In the field of vibration-based damage detection, finite element models are often used to plan field tests, to verify field test results, and to produce damaged data sets when the actual structure is unable to be damaged. As part of this research, finite element models were constructed to lend credibility to the field test results and to investigate damage scenarios other than those inflicted during the field tests.
Vibration-based Damage Assessment and Residual Capacity Estimation of Bridges
| Author | : Reza Baghaei Naeini |
| Publisher | : |
| Total Pages | : 154 |
| Release | : 2011 |
| Genre | : |
| ISBN | : 9781124521749 |
In this study, various aspects of vibration-based damage assessment of bridge structures are investigated. Results of application of novel methodologies in vibration-based damage assessment of structures in the presence of wide range of real seismic damage and from noisy and incomplete measurements are presented and discussed. The first part of this dissertation is devoted to experimental modal analysis. Two output-only and input-output system identification techniques are applied for identification of modal properties of the bridge from ambient vibrations and responses to high amplitude earthquake excitations respectively. An optimization-based finite element (FE) model updating methodology is applied for identification of damage characteristics by monitoring the variations in stiffness properties of critical elements of the bridge. A hybrid optimization procedure based on Genetic Algorithm (GA) and quasi-Newton optimization techniques is implemented for finding the best set of FE model parameters that minimizes the objective functions. Two objective functions are defined expressing the discrepancy between the measured and analytical response characteristics in time and modal domains. The meaningful agreement between FE model parameters identified using time and modal domains data with experimental stiffness indices indicates the efficiency and accuracy of the proposed damage identification procedure. In the final part of the dissertation, two vibration-based procedures are presented and applied for investigation of the consequences of damage in collapse capacity and functionality status of the bridge. The first procedure takes advantage of a double-integration and filtering routine to estimate the maximum drift ratios experienced by the lateral force resisting elements of the bridge from acceleration measurements. Estimated drift ratios along with pushover curves of the corresponding elements are used to calculate the ductility-based residual capacity of the elements and the bridge. The second procedure utilizes the incremental dynamic analysis (IDA) curves for estimation of collapse capacity of the bridge. A new approach for generation of FE model realizations of the earthquake damaged structures is proposed and applied. Generated FE realizations of the damaged bridge are used to estimate the collapse capacity of the structure. Amount of loss in collapse capacity along with seismic hazard characteristics at the bridge site and a set of tagging criteria are utilized for tagging and determination of the functionality status of the damaged bridge. Accuracy and reliability of the residual capacity estimation procedures are evaluated and verified by the results of a shake table experiment on a large-scale model of a reinforced concrete bridge.
Vehicle Scanning Method for Bridges
| Author | : Yeong-Bin Yang |
| Publisher | : John Wiley & Sons |
| Total Pages | : 288 |
| Release | : 2019-09-12 |
| Genre | : Technology & Engineering |
| ISBN | : 1119539498 |
Presents the first ever guide for vehicle scanning of the dynamic properties of bridges Written by the leading author on the subject of vehicle scanning method (VSM) for bridges, this book allows engineers to monitor every bridge of concern on a regular and routine basis, for the purpose of maintenance and damage detection. It includes a review of the existing literature on the topic and presents the basic concept of extracting bridge frequencies from a moving test vehicle fitted with vibration sensors. How road surface roughness affects the vehicle scanning method is considered and a finite element simulation is conducted to demonstrate how surface roughness affects the vehicle response. Case studies and experimental results are also included. Vehicle Scanning Method for Bridges covers an enhanced technique for extracting higher bridge frequencies. It examines the effect of road roughness on extraction of bridge frequencies, and looks at a dual vehicle technique for suppressing the effect of road roughness. A filtering technique for eliminating the effect of road roughness is also presented. In addition, the book covers the identification of bridge mode shapes, contact-point response for modal identification of bridges, and damage detection of bridges—all through the use of a moving test vehicle. The first book on vehicle scanning of the dynamic properties of bridges Written by the leading author on the subject Includes a state-of-the-art review of the existing works on the vehicle scanning method (VSM) Presents the basic concepts for extracting bridge frequencies from a moving test vehicle fitted with vibration sensors Includes case studies and experimental results The first book to fully cover scanning the dynamic properties of bridges with a vehicle, Vehicle Scanning Method for Bridges is an excellent resource for researchers and engineers working in civil engineering, including bridge engineering and structural health monitoring.
