Engineering Commons^™

Vibration Control Of A Two-Story Base-Isolated Building Using A New Tuned Mass Multi-Sliding Friction Damper, Mohsen Amjadian, Syed Muhammad Bilal Haider

Civil Engineering Faculty Publications and Presentations

This paper studies the use of a new Tuned Mass Multi-Sliding Friction Damper (TMMSFD) to increase the damping capacity of seismic isolators installed on a two-story base-isolated building to limit their lateral deformations. The proposed TMMSFD consists of a set of several masses that are laterally attached to the superstructure floor through linear springs. These masses are placed on top of each other one by one and are allowed to slide with respect to each other during the earthquake. The bottom mass that carries the weight of upper masses is in contact with the superstructure floor. The damping of system …

Investigations Into Flange Surface Friction Effects On Shear Stud Load Transfer In Composite Bridge Girders, Callie Clark

Graduate Theses and Dissertations

Composite bridge behavior is commonly achieved through headed shear studs welded tothe steel girder flange and embedded in the concrete deck. Current AASHTO provisions for estimating demands on shear studs during service-level loading consider only bearing load transfer, neglecting adhesion bonding and friction load transfer between the concrete deck and girder flange. Quantifying alternative load transfer mechanisms across the steel-concrete interface may result in improved steel bridge economy by reducing the number of studs required in a composite girder design. This study investigates the effects of flange surface friction (considering various coatings) on resulting stud demands using both experimental testing …

Stream Power Analysis Of The Mid-Barataria Conveyance Channel Model, Jack Graham

LSU Master's Theses

Louisiana’s coast is disappearing at an alarming rate. Erosion, subsidence, sea level rise, and the devastating impacts from hurricanes have contributed to the loss of thousands of square miles of land that was once a thriving ecosystem. The Louisiana government is taking action to help protect and restore these coastal habitats, which are a home to some two million people and numerous species of animals, birds, and fish. The Mid-Barataria Sediment Diversion is a new type of project to help create land in Barataria Basin. Conceptually, the diversion is designed to use the available sediment and stream power provided by …

Recovery Of Worn Parts By Electrodes, Sh.Kh. Yuldashev, M.N. Masharipov

Journal of Tashkent Institute of Railway Engineers

Studies have been worked on the restoration of various perishable parts with welding. The main purpose of the research is to increase the strength of the working surfaces of parts different coating by welding different types of covered electrodes. Studies have been carried out to determine the composition, structure, rigidity and eroding resistance of the welded covering material. As a result of laboratory research, the optimal composition of the covering material is determined and the optimal method of welding them to the eroded working surface of the parts is selected.

Calculation Of Seismic Resistance Of Reinforced Concrete Railway Spans Without Prestressing Reinforcement, U.Sh. Raxmanov, G.B. Ismailova

Journal of Tashkent Institute of Railway Engineers

The article discusses the calculation of earthquake resistance of reinforced concrete rail spans without prestressing reinforcement. The calculation is made for the main and special combination of loads. The calculation results show that with a design seismicity of 8 points, the bending moment in the middle of the beam span will significantly decrease compared to a design seismicity of 9 points

Increasing The Strength Of Worn Parts Withcomposite Materials, Masud Numonzhonovich Masharipov, Shuhratbek Xabibullo Ogli Yuldashev

Journal of Tashkent Institute of Railway Engineers

Researches are carried out on the built-up curly details. The aim of the study is to restore worn surfaces of parts by surfacing of powder composite materials. Inves-tigations are carried out to determine the composition, structure, hardness and wear resistance of the deposited layers. As a result of laboratory studies, the opti-mal composition of the surfacing material and the rational method of applying them to the worn surfaces of machine parts are selected.

Procedure For Asphalt Mixture Friction Evaluation For Wvdoh, Danielle Marie Hoyer

Graduate Theses, Dissertations, and Problem Reports

Monitoring asphalt skid resistance in the laboratory could aid in improved friction prediction capabilities and provide insight for developing alternative asphalt mixture designs in the future. The West Virginia Department of Highways (WVDOH) sought the design of a laboratory accelerated asphalt polishing machine to further expand on current skid resistance measurement practices. The design is modeled after the North Carolina State University (NCSU) polishing machine detailed in ASTM E660. The purpose of this research was to develop a testing procedure for the polishing equipment. Friction was monitored with the British Pendulum Tester (BPT) according to ASTM E303.

Specimens were prepared …

Development Of Electromagnetic Friction Dampers For Improving Seismic Performance Of Civil Structures, Mohsen Amjadian

Dissertations and Theses

Energy dissipation is critical to limiting damage to civil structures subjected to extreme natural events such as earthquakes. Friction is one of the most reliable mechanisms of energy dissipation that has been utilized extensively in friction dampers to improve seismic performance of civil structures. Friction dampers are well-known for having a highly nonlinear hysteretic behavior caused by stick-slip motion at low velocities, a phenomenon that is inherent in friction and increases the acceleration response of the structure under control unfavorably, in spite of the fact that the displacement is generally reduced because of the energy dissipation. This increase in acceleration …

Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin

Open Access Theses

The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted …

The Effects Of Bolt Pretension, In-Plane Eccentricity, And Friction On The Ductility Of Block Shear Connections, Kevin M. Zmetra

Master's Theses

Block shear is a complex failure mechanism in bolted and welded steel components such as gusset plates, webs of coped beams, angles and tees. It presumes a combination of tension rupture and shear yield. Multiple variables affect the block shear capacity and ductility of a connection. This study investigates the effects of bolt pretension, connection eccentricity and friction force transfer through a series of destructive experiments followed by refined finite element simulation. Clamping forces create a complex triaxial stress field compounded by the stress concentration at the bolt holes. In-plane load eccentricity with respect to the centerline of the connection …

Identification Of Laboratory Technique To Optimize Superpave Hma Surface Friction Characteristics, Karol J. Kowalski, Rebecca S. Mcdaniel, Jan Olek

JTRP Technical Reports

Wet pavement friction is known to be one of the most important roadway safety parameters. In this research, frictional properties of flexible (asphalt) pavements were investigated.

As a part of this study, a laboratory device to polish asphalt specimens was refined and a procedure to evaluate mixture frictional properties was proposed. Following this procedure, 46 different Superpave mixtures, one stone matrix asphalt (SMA) mixture and one porous friction course (PFC) mixture were tested. In addition, 23 different asphalt and two concrete field sections were also tested for friction and noise.

The results of both field and laboratory measurements were used …

Long Term Performance Of A Porous Friction Course, Rebecca S. Mcdaniel, Karol J. Kowalski, Ayesha Shah, Jan Olek, Robert J. Bernhard

JTRP Technical Reports

In 2003, the Indiana Department of Transportation and the Federal Highway Administration allowed a test section of Porous Friction Course (PFC) to be placed on I74 east of Indianapolis. The design, construction and early performance of that surface were compared to an adjacent SMA surface and a conventional Superpave HMA surface in a report prepared for the Institute for Safe, Quiet and Durable Highways (1). The early performance indicated that the PFC offered several advantages over the SMA and the conventional surfaces, including reduced tire/pavement noise, high friction and surface texture, and reduced splash and spray. There was …

Slides: Disappearing Roads--An Efd Project: An Exploration Into Low Impact And Efficient Gas Field Drilling, Charles Dolan

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center (HARC), for Dr. Charles Dolan, University of Wyoming, Environmentally Friendly Drilling Program

25 slides

Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla

LSU Master's Theses

Detournay and Tan (2002) performed experiments with a rock cutting device to measure the load required to fail the rock under confining stress. They proposed models describing the correlation between the specific energy and confining stress for shear dilatant rocks as a function of unconfined specific energy at failure, cutter rake angle (θ), internal friction angle (φ) of the rock and an assumed interface friction angle (ψ) between the rock and the cutter. The aim of this research is to evaluate the model proposed by Detournay and Tan (2002), which states that specific energy varies linearly with bore hole pressure …

Utilizing Gis Technology To Improve Indot Pavement Friction Data Management And Distribution, Karen Zhu

JTRP Technical Reports

Pavement friction condition provides an important parameter in selecting highway rehabilitation and maintenance projects. The Research Division of Indiana Department of Transportation has been conducting annual pavement friction testing on the Indiana highway network. Due to the large amount of data accumulated, an efficient system is in demand for data management. In this project, we developed a computer program that constitutes an integrated system for friction data management and distribution. In the developed system, database technology was utilized for data storage and organization; networking technology was utilized for real-time data distribution; geographic information systems (GIS) technology as well as computer …

Stay-In-Place Deck Panels - Horizontal Shear Strength Of Bridge Deck Panels - Part 2, Phani Kumar Nukala, J. A. Ramirez, Robert H. Lee, Menashi D. Cohen

JTRP Technical Reports

One of the most economic methods of bridge deck construction consists of prestressed concrete deck panels used in stay-in-place forms in conjunction with the cast-in-place concrete topping instead of the traditional monolithic roadway deck slabs. The performance of this type of deck as a composite unit is only possible if the horizontal shear stress resulting from bending of the deck if effectively transferred across the interface of the two elements. It is assumed that horizontal shear stresses are transmitted across the interface due to bond between the precast panel and cast-in-place concrete acting in conjunction with the horizontal shear connectors …

Frictional Performance Of Pavements And Estimates Of Accident Probability [Dec. 1980], James L. Burchett, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Objectives of this study were to evaluate standard and experimental surfaces throughout Kentucky in terms of skid resistance and effects of traffic, and to provide criteria for judging suitability of these surfaces to satisfy requirements for skid resistance and economics. The effects of traffic were quantified by regression analysis and scatter of data. Criteria included an estimate of accident risks, effects of speed on skid resistance, and seasonal variations in skid resistance.

Pavements on low volume roads (less than 1,000 vehicles per day) maintained adequate skid resistances. Open-graded friction courses, with the possible exception of sections using phosphate slag aggregate, …

Skid Resistance Of Pavements [Sept. 1972], Rolands L. Rizenbergs, James L. Burchett, Cass T. Napier

Kentucky Transportation Center Research Report

Standard pavement types and experimental surfaces on roads throughout Kentucky were evaluated in terms of skid resistance and effects of traffic, wear, and polishing. Friction-vs-speed gradients and the relationships between locked-wheel and incipient friction were determined. Asphaltic concrete pavements on high-speed, four-lane roads were found to be significantly more skid resistant than on two-lane highways and somewhat more skid resistant than concrete surfaces (especially those containing calcareous gravel aggregates). Sand-asphalt surfaces containing significant proportions of limestone sands showed inadequate level of friction for the traffic sustained. Several experimental sand asphalts without limestone sands exhibited greater skid resistance; Kentucky rock asphalt …

Florida Skid Correlation Study Of 1967 – Skid Testing With Automobiles, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The inclusion of automobiles in the Florida skid correlation study was promoted by the recognition of the following needs: 1) to compare stopping-distance measurements obtained with different instrumentation, 2) to suggest a standard method of stopping-distance testing, 3) to relate skid-resistance measurements of trailer-type testers with stopping distances of automobiles, and 4) to explore other skid-resistance measurements techniques using an automobile.

The vehicles were all full-size automobiles. Each vehicle was instrumented to measure a distance from a predetermined pressure in the brake hydraulic system to where the vehicle came to rest. Stopping distance in most of the automobiles was read …