Engineering Commons^™

Measurement Parameter Optimization For Surface Crack Detection In Metals Using An Open-Ended Waveguide Probe, R. Zoughi, Stoyan I. Ganchev, Christian J. Huber

Electrical and Computer Engineering Faculty Research & Creative Works

Fatigue and stress induced surface crack detection in metals is an important practical issue. A newly developed microwave inspection approach, using an open-ended rectangular waveguide, has proved to be an effective tool for detecting such cracks. This novel microwave approach overcomes some of the limitations associated with the standard detection methods for surface crack detection. In addition, this approach is applicable to exposed, filled (with a dielectric such as dirt, rust, etc.) and cracks under dielectric coatings such as paint. This paper presents the basic foundation of this surface crack detection methodology along with the ways by which measurement parameters …

Environmentally Safe Protective Coatings For Steel Structures-New Construction And Maintenance Painting, Theodore Hopwood Ii, Christopher M. Oberst

Kentucky Transportation Center Research Report

The purpose of this study was to: 1) assist KyTC in identifying protective coatings lor structural steel that would meet current and pending environmental regulations, I and 2) to evaluate overcoating procedures that would be cost-effective and provide regulatory (OSHA and EPA) compliance.

A coatings research program was conducted that included: 1) laboratory accelerated corrosion/weathering tests, 2) field exposure tests, and 3) experimental maintenance I painting of entire bridges by overcoating. Each of those tasks was intended to address different issues. Regulations concerning volatile organic compound limits lor coating systems used in new construction were studied and recommendations provided to …

Stay-In Place Deck Panels - Part 1, Ariel Goldman, Menashi D. Cohen, J. A. Ramirez

JTRP Technical Reports

The objective of this study was the evaluation of frost resistance of concrete bridge decks with stay-in-place galvanized steel deck forms. The evaluation included specific aspects related to the potential for D-cracking in concrete bridge decks with these forms. The experimental program has been set up so that the real parameters of the bridge deck overlays and the environmental conditions could have been modeled. The program included freezing-and-thawing testing of large concrete slab specimens (22 ¼” x 17 ¼” x 5 ¼”) situated in a computer-controlled environmental chamber and of small specimens (3” x 4” x 12”) immersed in water …

Fatigue Strength Of Girders With Tapered Covered Plates, Ahmed Farouk Hassan, Mark D. Bowman

JTRP Technical Reports

This report represents results from a study to determine the fatigue strength of steel beams with welded partial-length cover plates. Results of an experimental investigation that examined the fatigue strength of various cracked cover plate end details that were subsequently repaired are presented. The repair methods investigated included a slip-critical bolted splice plate connection, air-hammer peening, and a combination of the previous two called a partial bolted splice connection. Also, an analytical model was developed to predict the fatigue behavior of a cover plate and detail that is repaired using one of the three repair methods investigated and which contains …

Summary Of Stress Evaluations Of Welded Steel Bridges On Coal-Haul Routes, Theodore Hopwood Ii, Keith J. Hogan, Christopher M. Oberst

Kentucky Transportation Center Research Report

Stress analyses were performed on continuous girder welded steel bridges on extended weights coal-haul routes. The tests were intended to determine whether extended weight coal trucks pose fatigue problems to those bridges. Measurements were performed by strain gaging selected bridges subject to high coal transport tonnages. Stress measurements were conducted on fatigue-prone weld details or test sites where high tensile stresses were anticipated. Test sites on the bridges were instrumented with strain gages. Strains induced by routine traffic including coal trucks were monitored for periods of one to two weeks. Unattended monitoring of the variable amplitude strain data was performed …

The Role Of Thallium As A Hydrogen Entry Promoter On Cathodically Polarized Hy-130 Steel, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

Hydrogen permeation experiments were carried out to investigate the effect of thallium on hydrogen entry into HY-130steel. These experiments show that the presence of thallium ions in an electrolyte drastically increase the hydrogen entry rate. The hydrogen entry efficiency and hydrogen surface coverage were increased by a factor of 10 and 6, respectively. In order to fit the permeation experimental data, the Iyer-Pickering-Zamanzadeh (I-P-Z) hydrogen permeation model was modified by including a mass-transfer term in the discharging equation. The relationship between hydrogen permeation and the hydrogen evolution reaction were investigated and new relationships were obtained.

Stress Evaluation Of Welded Steel Bridges On Coal-Haul Routes, Theodore Hopwood Ii, Keith J. Hogan, Christopher M. Oberst

Kentucky Transportation Center Research Report

This report describes the procedure developed and being employed to determine and assess live-load stresses in structural members of welded steel bridges on extended· weight coal haul routes. Those bridges are routinely subjected to loads from coal trucks in excess of those permitted on other routes. Those elevated loads may result in high stresses in bridge members. Of principal concern are certain weld details on steel bridges that are susceptible to fatigue cracking when subject to high live-load stresses. Seventeen welded steel bridges on extended-weight coal haul routes have been identified for investigation under this study.

The study test procedure …

The Removal Of Lead-Based Paint From Steel Bridges, Theodore Hopwood Ii, Christopher M. Oberst

Kentucky Transportation Center Research Report

The purpose of this study was to assist the Department of Highways in conducting bridge-painting operations involving removal of existing lead-based paint. Pertinent state and Federal regulations affecting generation of hazardous wastes, limiting environmental pollution and protecting public and worker safety were obtained and reviewed.State highway agendas were surveyed relative to how they conducted maintenance bridge painting involving lead-based. paints and comply with applicable regulations. Information from the painting industry related to sale removal of lead-based paints was also reviewed.

Based upon the reviews of applicable regulations, operations of other state highway agencies and painting industry practices, the best demonstrated …

Surface Treatment For Mitigation Of Hydrogen Absorption And Penetration Into Aisi 4340 Steel, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The effectiveness of underpotential deposition of Pb onto a membrane made of AISI 4340 steel on the reduction of the hydrogen evolution reaction on the membrane and the degree of hydrogen ingress into the membrane was determined. In the presence of a monolayer coverage of Pb on the membrane surface, the hydrogen evolution currents were reduced by a factor of two compared with the values obtained on bare steel, and the steady-state hydrogen permeation flux through the steel membranes was reduced by 71%.

Survey Of Current Bridge Painting Practices And Related Literature Search, Theodore Hopwood Ii, Christopher M. Oberst

Kentucky Transportation Center Research Report

A survey on current bridge painting practices was conducted. Questionnaires were sent to all 50 state highway agencies concerning their present bridge painting practices, changes in those practices that they anticipate due to environmental regulations, and new or experimental painting practices they are investigating. Forty-three responses were received. Those are collated and presented in the appendices along with comments of the responders.

A literature search was conducted on publications related to painting of steel structures (since 1987). Forty-nine documents were identified as being relevant to the topic. Those documents are listed in bibliographic form in the appendices.

Mathematical Modeling Of Cathodic Protection Using The Boundary Element Method With A Nonlinear Polarization Curve, J. F. Fan, S. N. R Pakalapati, T. V. Nguyen, Ralph E. White, R. B. Griffin

Faculty Publications

The distributions of potential and current density around a cathodically protected pipeline in seawater were determined using the boundary element technique. A nonlinear polarization curve for a low carbon steel in artificial sea water was obtained from dc-potentiodynamic measurements and was fitted for use as the boundary condition on the pipe. The program was used to evaluate cases in which one or two aluminum sacrificial anodes are used to protect a low carbon steelpipe in seawater. The results show that the number of anodes, the sizes of the anodes, and the distance between the anodes and the cathode are of …

Comparing Electrochemical Impedance Spectroscopy Methods For Estimating The Degree Of Delamination Of Organic Coatings On Steel, S. A. Mccluney, S. N. Popova, Branko N. Popov, Ralph E. White, R. B. Griffin

Faculty Publications

Electrochemical impedance spectroscopy (EIS) was used to evaluate the degree of delamination of the epoxy primer Uniprime ED-4¹ electrocoated on phosphate-treated cold-rolled steel in 3.5% NaCl exposed to air. Specimens with coating thicknesses of 20.3 and 20.8 µm and surface areas of 78.5 cm² were used. Coating parameters were obtained using a circuit-analog model. The area of delamination was estimated using several EIS parameters, including the pore resistance and the break point frequency. These values were compared to the corroded area determined visually. All methods considered exhibited a strong correlation over some or all of the range of …

Load Indicating Washers, Theodore Hopwood Ii, Edgar E. Courtney

Kentucky Transportation Center Research Report

Kentucky Transportation Center (KTC) personnel monitored the installation of load indicating washers (LIWs) on the US 60 bridge at Catlettsburg, KY during construction. On completion of the bridge, KTC personnel performed torque measurements on a number of LIW installations. LIWs previously installed on the Thirteenth Street Bridge over the Ohio River at Ashland, KY were also inspected.

The KTC construction inspections revealed no significant problems in installing LIWs. Workers were able to use them to determine proper bolt assembly installation. They also permitted inspectors to rapidly check for proper bolt tension. As with other bolt tensioning methods, LIWs had to …

Fatigue Analysis Of The I-75 Bridge Over The Kentucky River At Clays Ferry, Theodore Hopwood Ii, Vishwas G. Oka

Kentucky Transportation Center Research Report

Fatigue analysis was performed on AASHTO category E welded connections on the southbound I 75 bridge over the Kentucky River at Clays Ferry, Kentucky. That analysis was based on the stress-range histogram data provided by Law Engineering of Louisville, Kentucky. That data were obtained from strain gages installed at 6 test locations on the downstream truss.

The fatigue analyses consisted of safe-life and fatigue-crack growth analyses. Safe-life predictions were based on AASHTO fatigue design (SN) curves. To use those curves, equivalent constant-amplitude stresses were derived from the stress histograms. Those stresses and loading frequencies were modified to reflect anticipated increases …

Calcium Nitrite As A Corrosion Inhibitor In Reinforced Concrete Bridge Decks, Theodore Hopwood Ii, David Q. Hunsucker, Edgar E. Courtney

Kentucky Transportation Center Research Report

The use of calcium nitrite es a corrosion-inhibiting admixture in reinforced concrete hes been studied on two bridges· the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyle County. Calcium nitrite was added to concrete used in the slabs, diaphragms and barriers of the KY 152 bridge and only in the slab of the Good Road bridge.

Construction of both structures was monitored in the fall of 1986. Placement of concrete on both bridges was satisfactory; however, problems were experienced in finishing the concrete. The finishing problems were related to: 1) concrete 'stickiness', 2) use of …

Excessive Beam Deflections On The Ky-52 Bridge Over Dix River (Boyle-Garrard County Line), Theodore Hopwood Ii, Vishwas G. Oka, David Q. Hunsucker, James H. Havens

Kentucky Transportation Center Research Report

Upon rehabilitation, beams and deck of the Ky 52 bridge over Dix River were observed to have excessive deflections. An investigation of the problem included field inspections, structural analyses, and interviews with relevant KYDOH and other personnel.

Field measurements were made of the beam deflections. Those were compared to construction field measurements and dead-load calculations.

The beam deflection problem is attributed to 1) a failure to provide for sufficient camber in the beams to accommodate for construction dead loads, and 2) pre-existing sags in the beams when placed prior to casting the deck. Part of the deck deflection problem can …

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 …

Stability Of Steel Structures, Abbas K. Hosseini

Retrospective Theses and Dissertations

In the design of an elastic structure, a major consideration is the overall stability of the system under axial load or a combination of an axial load and bending moment. In first-order analysis the effects of axial forces on the stiffness formulation and their influence on deformations of the members are usually neglected. If the axial forces are sufficiently large, a better indication of the distribution of the forces and moments in the structure is obtained by using a second-order analysis. In this type of analysis the moment equilibrium equations are based on the deformed shape of the structure. The …

Corrosion Of Cable Suspension Bridges, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

This report discusses corrosion problems encountered on the cables of suspension bridges. A historical review is given of past cable suspension bridge corrosion and related laboratory work.

Findings of inspections of suspension bridges at Maysville, KY, Covington, KY, and Portsmouth, OH, are discussed. Recommendations are presented.

Inspection, Prevention, And Remedy Of Suspension Bridge Cable Corrosion Problems, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

This report discusses methods for visually inspecting cable suspension bridges for corrosion damage. The report discusses how to plan and perform such work, including the locations on cables where corrosion damage is likely to be detected. The report also provides recommendations for assessing the condition of suspension bridge wire. Recommendations also are included for remedial cable repair work should corrosion damage be detected.

Introduction To Cable Suspension Bridges, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

This report is an overview of suspension bridges. A historical perspective of bridge construction design and materials is included, focusing on bridges of interest to the Kentucky Transportation Cabinet. The report is intended to provide background information on suspension bridges to those not well acquainted with the structures.

Acoustic Emission Monitoring Of Weldments, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

Weld tests were performed on low-carbon and high-strength, low-alloy steel weldments. The weldments were monitored with an acoustic emission detector during both the 'in-process' and the 'in-cooling' phases of the welding operation. Artificial defects were induced in several of the welds to promote cracking. Some high-strength weldments were designed to produce welds subject to high restraint.

Nondestructive and destructive evaluation of the completed weldments revealed that high acoustic emission activity 'in-cooling' could be correlated with embedded defects and cold-cracking. Copious emission activity was also detected from unflawed weldments. Acoustic emissions were detected in high-strength steel weldments for periods up to …

The Corrosion Of Zinc-Stainless Steel Couples In Flowing Sea Water, Henry Shaw

Theses

The effect of sea water flow on passivated stainless steel 304 coupled to high purity zinc was studied for more than 1000 hours at 23°C. The corrosion of both members of the couple increased over that of the metals alone. Zinc suffered severe pitting while the Stainless Steel was not visibly corroded, When the metals were exposed alone, zinc corroded uniformly while the stainless steel was not affected at all. The use of zinc coupled to Stainless Steel is not recommended in systems exposed to sea water.

Investigation Of Inclusions In Armco Ingot Iron, Edwin J. Duncan

Bachelors Theses and Reports, 1928 - 1970

Various chemical and electrolytic separation methods were investigated in an attempt to separate the in­clusions in Armco ingot iron. Residues obtained were X-rayed for identification purposes. The microstruc­tures of this iron were studied with the object of de­termining the relative sizes, locations, and possible compositions of the inclusions.

The Steel Industry Of India: Its Historical Background And Present Development, Glenn Kaufmann

University of the Pacific Theses and Dissertations

Ancient India was reported to produce excellent iron products that were prized in all parts of the world. Not only did she make swords, plow points, and other products necessary for the useful arts, but also ornaments such as ear and finger rings, and iron ornaments to beautify her buildings. India today, though to a lesser degree, is still carrying on the tradition of hand-made iron ornaments, by using the ancient method of smelting and processing. Indian wootz, a product similar to steel, was the best iron product made in olden times, and only India's failure to develop new and …

Studies Of Tempering Behavior Of Steel X-9165 Of N-A-X 9100 Series, James A. Ndulue

Bachelors Theses and Reports, 1928 - 1970

One of the reasons why steel is the most versatile of all the metals available for engineering applications is because of the wide range of properties that can be obtained from it by proper heat treatment.

Electroplating Of Chromium, Nickel And Copper Upon Titanium, Stanley O. Fong

Bachelors Theses and Reports, 1928 - 1970

Recently, there has been a great amount of research work done on the metal titanium. Since it is a light weight metal, with unusual strength and good resistance to corrosion, it may be a possible substitute for aluminum and magnesium alloys, or steel.

The Influence Of Copper Upon The Age Hardening Properties Of Steel, Andre Rey

Bachelors Theses and Reports, 1928 - 1970

The virtues of alloy steels have been widely publi­cized in both technical literature and everyday adver­tising. Nearly everyone possessing a slight knowledge of metallurgy knows the beneficial effects of chromium in the manufacture of stainless steels, or the importance of nickel, molybdenum, vanadium, and other common elements used to alloy steels.