Engineering Commons^™

Cyber-Physical Codesign Of Distributed Structural Health Monitoring With Wireless Sensor Networks, Gregory Hackmann, Weijun Guo, Guirong Yan, Zhuoxiong Sun, Chenyang Lu, Shirley Dyke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Our Deteriorating Civil Infrastructure Faces the Critical Challenge of Long-Term Structural Health Monitoring for Damage Detection and Localization. in Contrast to Existing Research that Often Separates the Designs of Wireless Sensor Networks and Structural Engineering Algorithms, This Paper Proposes a Cyber-Physical Codesign Approach to Structural Health Monitoring based on Wireless Sensor Networks. Our Approach Closely Integrates 1) Flexibility-Based Damage Localization Methods that Allow a Tradeoff between the Number of Sensors and the Resolution of Damage Localization, and 2) an Energy-Efficient, Multilevel Computing Architecture Specifically Designed to Leverage the Multiresolution Feature of the Flexibility-Based Approach. the Proposed Approach Has Been Implemented …

Noise-Insensitive Prognostic Evaluation Of Historic Masonry Structures, Ashley Haydock

All Theses

In recent years, a significant amount of research has been directed towards the development of prognostic methodologies to forecast the future health state of an engineering system assisting condition based maintenance. These prognostic methods, having furthered the maintenance practices for mechanical systems, have yet to be applied to historic masonry structures, many of which stand in an aged and degraded state. Implementation of prognostic methodologies to historic masonry structures can advance the planning of successful conservation and restoration efforts, ultimately prolonging the life of these heritage structures. This thesis presents a review of prognostic concepts and techniques available in the …

Analytical And Experimental Study Of Monitoring For Chain-Like Nonlinear Dynamic Systems, Bryan Paul

Electronic Theses and Dissertations

Inverse analysis of nonlinear dynamic systems is an important area of research in the eld of structural health monitoring for civil engineering structures. Structural damage usually involves localized nonlinear behaviors of dynamic systems that evolve into different classes of nonlinearity as well as change system parameter values. Numerous parametric modal analysis techniques (e.g., eigensystem realization algorithm and subspace identification method) have been developed for system identification of multi-degree-of-freedom dynamic systems. However, those methods are usually limited to linear systems and known for poor sensitivity to localized damage. On the other hand, non-parametric identification methods (e.g., artificial neural networks) are advantageous …

Acoustic Emission Source Characterization Of Fatigue Crack Extension In Steel Bridge Material, Md Mozahid Hossain

Theses and Dissertations

The probability of Acoustic Emission (AE) detection associated with fatigue crack extension in steel bridge components is a difficult problem due to the complexity of the AE sources. AE is a very promising technique for structural health monitoring and automated micro-crack detection as it is generated by the material itself, unlike other nondestructive testing techniques (for example impact echo and ultrasonics), which require external input sources. Characterizing the source of AE is an ongoing challenge because AE sensors are not only sensitive to the AE signals but also to mechanical noise and reflections. It is therefore difficult to interpret the …

Statistical And Numerical Integrated Approach For Detecting Onset Of Prefabricated Bridge Component Connection Deterioration, Cem Mansiz

Masters Theses

Bridges are the substantial part of the transportation infrastructure. Most recent report shows that of the 605,086 bridges in the United States, 67,526 (11%) are deemed structurally deficient, and 76,363 (13%) are declared functionally obsolete (FHWA, 2011). Deck is the shelter of a bridge that is subjected to severe loads due to exposure and traffic. Importance of detecting deck deterioration is further highlighted with the introduction of accelerated bridge construction (ABC) where prefabricated components are brought to the site, assembled, and connected using field cast joints. However, durability performance of field cast connections is not encouraging. Hence, continuous monitoring of …

Soft Capacitive Sensor For Structural Health Monitoring Of Large-Scale Systems, Simon Laflamme, M. Kollosche, J. J. Connor, G. Kofod

Simon Laflamme

Structural integrity of infrastructures can be preserved if damage is diagnosed, localized, and repaired in time. During the past decade, there has been a considerable effort to automate the process of structural health monitoring, which is complicated by the inherent large size of civil structures. Hence, a need has arisen to develop new approaches that enable more effective health monitoring.In this paper, a new sensing technique for damage localization on large civil structures is proposed. Specifically, changes in strain are detected using a capacitance sensor built with a soft, stretchable dielectric polymer with attached stretchable metal film electrodes. A change …

Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe

Electronic Theses and Dissertations

Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …

Implementing A Long-Term Bridge Monitoring Strategy For A Composite Steel Girder Bridge, Shelley Plude

Master's Theses

The University of Connecticut and the Connecticut Department of Transportation have established a long-term bridge health monitoring system to monitor critical vulnerabilities in a group of bridges throughout the state. This research focuses on a three-span, simply supported composite steel girder bridge carrying three lanes of highway traffic. It has been a part of the University of Connecticut and Connecticut Department of Transportation monitoring network since 2004 and is fitted with 20 strain gauges located at midspan at the top and bottom of the web of each girder.

To monitor the critical vulnerabilities of the bridge, it is important to …

Structural Health Monitoring Of Historic Masonry Monuments, Saurabh Prabhu

All Theses

Structural Health Monitoring (SHM) is a well-accepted diagnostic technique being used to evaluate modern structures. This method involves monitoring the vibration response of a structure to detect changes in its structural state. The primary intention of this thesis is to address two practical and technical difficulties encountered in deploying SHM on historic masonry monuments: (i) the selection of suitable low dimensional vibration response features that are highly sensitive to the presence and extent of damage, while having low sensitivity to extraneous noise and (ii) the selection of optimal sensor locations for efficient system identification applied to Gothic Cathedrals. Both of …

Structural Health Monitoring For Damage Detection Using Wired And Wireless Sensor Clusters, Thomas Terrell

Electronic Theses and Dissertations

Sensing and analysis of a structure for the purpose of detecting, tracking, and evaluating damage and deterioration, during both regular operation and extreme events, is referred to as Structural Health Monitoring (SHM). SHM is a multi-disciplinary field, with a complete system incorporating sensing technology, hardware, signal processing, networking, data analysis, and management for interpretation and decision making. However, many of these processes and subsequent integration into a practical SHM framework are in need of development. In this study, various components of an SHM system will be investigated. A particular focus is paid to the investigation of a previously developed damage …

Applications Of Electricity In The Rehabilitation And Health Monitoring Of Concrete Structures, Saiprasad Vaidya

Doctoral Dissertations

The dissertation research work presented herein consists of two separate findings: one investigates a potential new coating technique that could be used to rehabilitate deteriorated concrete sewer pipes, and the other researches inducing electrical conductivity into geopolymer concrete to serve as smart material by being able to sense stress changes. Both applications utilize electricity to enhance the performance and/or functionality of hardened cementitious materials.

Microbiologically induced corrosion (MIC) in concrete wastewater conveyance systems is a leading deterioration mechanism in such structures. This work focuses on breaking the MIC cycle by preventing colonization of the bacteria responsible for converting hydrogen sulfide …

Development Of An Ultrasonic Nde&T Tool For Yield Detection In Steel Structures, Yilmaz Bingol

LSU Doctoral Dissertations

Nondestructive Evaluation and Testing (NDE&T) is a commonly used and rapidly growing field that offers successful solutions for health assessment of structures. NDE&T methods have gained increasing attention in the last few decades especially with the contribution of the advancements in computer and instrumentation technologies. The applications of numerous NDE&T methods in civil engineering mostly focus on material characterization and defect detection. Techniques for nondestructively identifying the stress state in materials, on the other hand, mostly rely on the Theory of Acoustoelasticity. However, the sensitivity and the accuracy of acoustoelasticity are affected by several factors such as the microstructure of …

Damage Detection In Ambient Vibration Using Proportional Flexibility Matrix With Incomplete Measured Dofs, Zhongdong Duan, Guirong Yan, Jinping Ou, Billie F. Spencer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Structural Damage Detections based on the Changes of Dynamic Properties Are a Major Concern Tor Structural Health Monitoring. in This Paper. Efforts Are Made to Extend the Flexibility-Based Damage Localization Methods, Especially the Damage Locating Vector (DLV) Method, to the Case of Ambient Vibration with Incomplete Measured Degree of Freedom, Where Flexibility Matrices Are Not Available. First, the Method to Assemble a Proportional Flexibility Matrix (PFM) with Arbitrarily Scaled Modal Shapes of Full Measured Degrees of Freedom (DOF) is Introduced. the PFM is within a Scalar Multiplier to the Real Flexibility Matrix, and the Multiplier is Shown to Be the …

Structural Condition Assessment Of Prestressed Concrete Transit Guideways, Robert Zachary Shmerling

Electronic Theses and Dissertations

Objective condition assessment is essential to make better decisions for safety and serviceability of existing civil infrastructure systems. This study explores the condition of an existing transit guideway system that has been in service for thirty-five years. The structural system is composed of six-span continuous prestressed concrete bridge segments. The overall transit system incorporates a number of continuous bridges which share common design details, geometries, and loading conditions. The original analysis is based on certain simplifying assumptions such as rigid behavior over supports and simplified tendon/concrete/steel plate interaction. The current objective is to conduct a representative study for a more …