Engineering Commons^™

Damage Detection In Reinforced Concrete Member Using Local Time-Frequency Transform Applied To Vibration Measurements, Ning Liu, Thomas Schumacher, Yan Li, Lina Xu, Bo Wang

Civil and Environmental Engineering Faculty Publications and Presentations

Signal processing and analysis of structural vibration measurements are key components of structural damage detection (SDD) in structural health monitoring (SHM). The goal of signal processing is to extract subtle changes in the measured signals, which can be used to infer changes in structural parameters and damage. Time-frequency analysis is one of the most popular characterization methods for studying non-stationary vibration signals. In this article, the local time-frequency transform (LTFT) is applied and evaluated to calculate the time-domain signals because of its excellent time-frequency energy distribution properties. The LTFT matches the input data by the Fourier basis in an inverse …

Nondestructive Evaluation Of Structural Defects In Concrete Slabs, Ehsanul Kabir

Electronic Theses and Dissertations

Nondestructive testing (NDT) is a reliable method for determining the structural integrity of new and old construction and understanding the condition of structural defects. It is widely acknowledged that the interpretation of nondestructive evaluation (NDE) has a significant impact on the reliability and consistency of this technology. However, NDT data acquisition remains subjective and heavily dependent on the operator’s knowledge and expertise. As a result, there are still issues to be resolved regarding the imaging and diagnostic procedures for NDT-based concrete inspection. NDT methods such as ground penetrating radar (GPR), and impact-echo (IE), have been extensively used to inspect concrete …

Multi-Sensor Data Collection And Fusion Using Autoencoders In Condition Evaluation Of Concrete Bridge Decks, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Kwanghee Won, Brian A. Mazzeo, W Spencer Guthrie

Department of Civil and Environmental Engineering: Faculty Publications

This paper presents a multi-sensor data collection and data fusion procedure for nondestructive evaluation/testing (NDE/NDT) of a concrete bridge deck. Three NDE technologies, vertical electrical impedance (VEI), ground-penetrating radar (GPR), and high-definition imaging (HDI) for surface crack detection, were deployed on the bridge deck. A neural network autoencoder was trained to quantify the relationship between VEI and GPR results using the data collected at common positions. This relationship was then used for fusion of VEI and GPR data to increase the reliability and spatial resolution of the NDE measurements and to generate a data-fused condition map that showed novel characteristics. …

Prediction Of The Compressive Strength And Dynamic Modulus Of Fiber Reinforced Concrete By Ultrasonic Pulse Velocity Measurement At Early Ages, Daniel A. Castillo Pereira

Electronic Theses and Dissertations

This research investigates the relationship between early age ultrasonic pulse velocity and the compressive strength and dynamic modulus of steel, polypropylene, nylon, and glass fiber reinforced concrete. Previous studies prove that adding fibers to concrete alters the propagation of ultrasonic pulse velocity waves. Therefore, each type of fiber-reinforced concrete will have a unique relationship between ultrasonic pulse velocity and its compressive strength and dynamic modulus depending on fiber type, fiber volume fraction, water to cement ratio, and test age. To test this hypothesis, an experimental program comprising of one hundred eighty-nine 100 mm x 200 mm fiber reinforced concrete cylinders …

Evaluation Of Low And High Frequency Dynamic Response For Condition Assessment Of Reinforced Concrete Structures, Ali Hafiz

Dissertations and Theses

Concrete is widely used for civil infrastructure structures and they experience deterioration and degradation due to aging, increases in the traffic loads, harsher environmental conditions, use of deicing chemicals, etc. Therefore, evaluating the integrity of reinforced concrete structures has become of increasing interest for infrastructure owners and managers. A number of non-destructive testing (NDT) and structural health monitoring (SHM) methods have been developed in recent decades to aid in evaluating structures and provide input for asset management. One family of these methods uses the dynamic response of a structural member: stress waves (high frequency) and structural vibrations (low frequency). Both …

Diagnostic Imaging Of Structural Concrete Using Ground Penetrating Radar And Ultrasonic Array, Sina Mehdinia, Thomas Schumacher, Eric Wan, Xubo Song

Student Research Symposium

Structural concrete is the most widely used construction material in the world. Many structures critical to a society such as bridges, hospitals, and airports are built with concrete. While this material is well understood from a mechanical design point of view, still no accurate quantitative tools exist to assess it for damage and deterioration. This is of particular concern for an urban area like Portland with a mega-thrust earthquake waiting to occur. Non-destructive evaluation tools that can quickly and accurately give a full picture of the integrity of structural concrete elements will be key to help plan effective and safe …

Continuous Long-Term Health Monitoring Using Ultrasonic Wave Propagation, Ece Erdogmus

Nebraska Department of Transportation: Research Reports

No abstract provided.

Field Observation Of Installation And Performance Of Repair Materials, Larisa Diana Susinskas

ETD Archive

The state of Ohio is in a region that commonly experiences drastic changes in weather. States with similar climates are susceptible to pavement cracking and failures due to the frequent or extreme freeze-thaw cycles. Freeze-thaw cycles, paired with de-icing chemicals that are frequently placed on roadways during the winter months will most likely lead to pavement cracks and failure. Ohio Department of Transportation (ODOT) routinely repairs and replaces sections of concrete roadways and bridge decks. Therefore, ODOT is seeking durable, cost-effective materials to repair smaller pavement failures.

The purpose of this study is to determine which high performance repair materials …

Test And Evaluation Of Ultrasonic Additive Manufacturing (Uam) For A Large Aircraft Maintenance Shelter (Lams) Baseplate, Daniel H. Gartland

Theses and Dissertations

Additive manufacturing is an exciting new manufacturing technology that could have application to Air Force Civil Engineer (CE) operations. This research replicates a Large Area Maintenance Shelter (LAMS) baseplate design for ultrasonic additive manufacturing (UAM). Due to production problems the test section was not built as designed. Instead, a smaller block of material was submitted for evaluation. After the UAM build, ultrasonic inspection was conducted to identify anomalies in the test piece. The results of this proof of concept study indicate that UAM is not yet ready for CE expeditionary applications requiring a high degree of mechanical strength. The machine …

Optimization Of Stress Wave-Based Nondestructive Methods In Identifying Deterioration In Concrete Structures, Hoda Azari

Open Access Theses & Dissertations

The transportation infrastructure across the United States is deteriorating and requires periodic inspection to predict the cost of repair and extent of maintenance activities, to remedy structural problems, and to ensure safety and serviceability. The use of nondestructive testing (NDT) methods in detecting and characterizing flaws in the infrastructure has become more common. Among different NDT methods, the stress wave-based methods, including ultrasonic surface waves (USW) and impact echo (IE) methods, are widely used to maintain concrete structures. In this dissertation, a complete literature review of seismic wave theory and wave propagation in plate like structures, and stress wave-based methods …

Experimental Verification Of The Linear Relationship Between Stress And The Reciprocal Of The Peak Barkhausen Voltage In Astm A36 Steel, Orfeas Kypris, Ikenna Nlebedim, David Jiles

Orfeas Kypris

This study presents an experimental validation of a model theory for determining the relationship between a nondestructive measurement parameter and a property of interest. It was found that the reciprocal of the peak envelope amplitude of the Barkhausen emission voltage follows a linear relationship with stress. A linear relationship between stress and the reciprocal of the root mean square voltage was also obtained. These observations represent an important step towards improving the use of Barkhausen signals for magnetic non-destructive evaluation of stress as a function of depth in ferromagnetic load bearing structures.

Evaluation Of Nondestructive Technologies To Assess Presence And Extent Of Delamination Of Hot Mix Asphalt Airfield Pavements, Manuel Celaya

Open Access Theses & Dissertations

Sufficient bonding between the hot mix asphalt layers is essential to ensure the desired structural capacity of a pavement. Delamination or debonding problems are particularly more severe on airfield pavements, due to higher traffic loads applied by aircrafts. Further progression of delamination may result in stripping of the lower layers due to the intrusion of moisture or may develop other dangerous distresses such as foreign object debris. The existing nondestructive testing procedures and equipment that have the potential to address the problem were identified and their effectiveness and potential for success were evaluated. The Ground Penetrating Radar, Falling Weight Deflectometer, …

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 …

Long-Term Evaluation Of The Acoustic Emission Weld Monitor, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

The Kentucky Transportation Research Program conducted an extended 10- month evaluation of the Acoustic Emission Weld Monitor (AEWM) in a bridge fabrication shop. That device was used to detect welding flaws during typical production of butt-welds on flanges and webs used in steel bridges. A total of 153 welds were monitored.

AEWM test results were compared with visual inspection and double- blind results of conventional nondestructive testing routinely conducted on the welds. The AEWM did not miss any flaws detected visually or by nondestructive testing. Three AEWM flaw indications were confirmed by conventional nondestructive testing (radiography).

A large number of …

Reliability Assessment Of High-Risk Steel Bridges By Nondestructive Test Methods, Theodore Hopwood Ii, Vishwas G. Oka, Robert C. Deen

Kentucky Transportation Center Research Report

Fatigue-crack related failures of high-risk (fracture-critical) steel bridges may be prevented through application of nondestructive tests (NDT). Economical reliability assessment of those structures requires 1) application of a suitable NDT method, 2) testing of fatigue-susceptible members, and 3 ) periodic retests of those members to preclude problems with growing or previously undetected flaws.

Six conventional NDT techniques were tested in the laboratory using buttweld configured specimens having intentionally embedded cracks. Those NDT methods were 1) visual inspection, 2) magnetic-particle testing, 3) dyepenetrant testing, 4) florescent-enhanced surface testing, 5 ) eddy-current testing, and 6) ultrasonic testing. The other NDT methods provided …

Acoustic Emission Monitoring Of In-Service Bridges, Theodore Hopwood Ii, David W. Prine

Kentucky Transportation Center Research Report

An experimental acoustic emission (AE) device, the GARD Acoustic Emission Weld Monitor (AEWM), has been field tested on six bridges during this study. In addition, the device was used to test three other bridges under separate contracts from state highway agencies. The device was evaluated to determine if it could detect fatigue-crack growth on in-service steel bridges.

The AEWM employs a proprietary three-step model (filter) to reject noise-related AE activity and detect and locate defects subject to varying stress conditions. The unit uses built-in microprocessors to compare incoming data to the model. If defect-related AE activity is detected, the AEWM …

Demonstration And Preliminary Evaluation Of The Acoustic Emission Weld Monitor, Theodore Hopwood Ii, Robert C. Deen

Kentucky Transportation Center Research Report

This report describes the demonstration and preliminary evaluation of the microprocessor-based acoustic emission weld monitor (AEWM) developed for the Federal Highway Administration by GARD Inc. of Niles, IL. The equipment was tested successfully on butt welds in several fabrication shops by the Kentucky Transportation Research Program (KTRP). Some problems were encountered in monitoring fillet welds.

The AEWM was demonstrated to personnel from 20 state agencies representing FHWA Regions 1, 3, 4, and 5. The demonstrations were performed at three different fabrication shops in Pennsylvania, Georgia, and Wisconsin.

A preliminary evaluation of the AEWM is included. Also, the summary of a …