Engineering Commons^™

Effect Of Column Axial Load On Skewed Smf Rbs Connection Demands, Clovis Desrochers

Graduate Theses and Dissertations

Steel buildings in high seismic areas often require special structural systems to transfer large lateral forces induced by earthquake accelerations. The selection of an appropriate seismic steel system (braced frame, moment frame, shear wall, etc.) is often influenced by architectural considerations. Moment frame configurations offer the most architectural flexibility, but are limited by code prequalification requirements that limit the use of non-orthogonal (skewed) beam-column connection geometries. A recent study has investigated laterally skewed moment frame connections, indicating that skew increases the potential for column twist and column flange yielding; however, it is unclear how realistic column axial loads will affect …

A Comparison Of Force And Pressure Coefficients On Dome, Cube And Prism Shaped Buildings Due To Straight And Tornadic Wind Using Three Dimensional Computational Fluids Dynamics, Majdi A. A. Yousef

Graduate Theses and Dissertations

Tornadoes induce very different wind forces than a straight-line (SL) wind. A suitably designed building for a SL wind may fail when exposed to a tornado-wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Most studies have been conducted to investigate tornado forces on cubic, gable-roof and cylinder buildings. However, little attention has been paid to investigate tornado force on dome buildings; hence, further research is conducted in this study. The forces on a dome, cube and prisms were analyzed and compared using Computational Fluid Dynamics (CFD) for tornadic and SL …

Identifying Damage, Predicting Expansion, And Determining The Effectiveness Of Sealers On Concrete Affected By Alkali-Silica Reaction And Freeze-Thaw, Matthew Caleb Waidner

Graduate Theses and Dissertations

Premature cracking of the barrier wall and pavement on I-49 south of Fayetteville, Arkansas due to a combination of Alkali-Silica Reaction (ASR) and freeze-thaw has led to ASR and freeze-thaw research at the University of Arkansas. Potential for further expansion (PFET), Damage Rating Index (DRI), and mitigation of freeze-thaw and ASR with sealers testing and results are contained herein. PFET results indicated that the pavement will not continue to expand from ASR. With other interstate pavements deteriorating prematurely throughout Arkansas, DRI has shown that most are damaged not only by ASR but by freeze-thaw too. Recommendations for freeze-thaw’s inclusion into …

Creep, Fatigue And Creep-Fatigue Interactions In Modified 9% Cr - 1% Mo (P91) Steels, Valliappa Kalyanasundaram

Graduate Theses and Dissertations

Grade P91 steel, from the class of advanced high-chrome ferritic steels, is one of the preferred materials for many elevated temperature structural components. Creep-fatigue (C-F) interactions, along with oxidation, can accelerate the kinetics of damage accumulation and consequently reduce such components' life. Hence, reliable C-F test data is required for meticulous consideration of C-F interactions and oxidation, which in turn is vital for sound design practices. It is also imperative to develop analytical constitutive models that can simulate and predict material response under various long-term in-service conditions using experimental data from short-term laboratory experiments. Consequently, the major objectives of the …

Development Of Mems-Based Corrosion Sensor, Feng Pan

Graduate Theses and Dissertations

This research is to develop a MEMS-based corrosion sensor, which is used for monitoring uniform, galvanic corrosion occurring in infrastructures such as buildings, bridges. The corrosion sensor is made up of the composite of micro/nano metal particles with elastomers. The mechanism of corrosion sensor is based on the mass transport of corrosive species through the sensor matrix. When the metal particles in the matrix corrode, the electrical resistivity of the material increases due to increasing particle resistances or reduction of conducting pathways. The corrosion rate can be monitored by detecting the resistivity change in sensing elements. The life span of …

Improved Protocols For Automated Wheelpath Crack Detection In Pavements, Daniel Patrick Byram

Graduate Theses and Dissertations

Roadway pavement distress evaluations are vital to understanding the mechanics of pavement stability, determining the distribution of rehabilitation costs, and knowing the appropriate rehabilitation strategies. Advancements in technology over the past two decades have changed the way these surveys have been performed by means of automated data collection and interpretation. More and more state agencies have invested in automated road analyzing vehicles that are able to collect high resolution images of the pavement. Fewer have adopted automated data processing software with the ability to interpret road distresses due to the common discrepancies in distress classification algorithms.

In addition to automated …

Computer Modeling Of The Influence Of Structure Plan Areas On Tornado Forces, Nashmi Hassan M Alrasheedi

Graduate Theses and Dissertations

The study of the conventional Straight Line (SL) wind flow dominates research into wind loads on structures. Most structure design takes into account only research into SL flow. Few researchers have studied tornado forces on buildings and attempted to distinguish between tornadic wind loads and SL flow loads. Using a computer simulation, this research addresses and distinguishes between the tornadic forces and SL forces on structures. In the numerical simulation, tornado forces and SL forces will be compared on large structure plan areas and on thin structure plan areas. Additionally this research investigates how the increase in the vortex strength …

Slope Stability Monitoring Using Remote Sensing Techniques, Omar Alberto Conte Robles

Graduate Theses and Dissertations

During the past six years the Arkansas State Highway and Transportation Department (AHTD) has spent over nine million dollars repairing slope failures that have occurred in the state of Arkansas. Specifically, higher than average precipitation in 2004 and 2008 led to large quantities of slides, all of which were repaired. Two highways, within the state of Arkansas, with known historical movements along or across the highways are being monitored using traditional surveying techniques and advanced remote sensing techniques. These slides, both of which are located in fill slopes. One a 500-foot long slide located north of Chester, Arkansas, within the …

Laboratory Evaluation Of Dynamic Characterization Methods For Rapid Condition Assessment Of Bridges, Jason Kyle Herrman

Graduate Theses and Dissertations

The objective of this thesis was to devise and refine Structural Health Monitoring methods and the associated quantitative characterization methods with the specific goal of enabling rapid and reliable safety evaluations of bridges following natural or manmade hazards. Presently, the safety and serviceability of these transportation infrastructure assets for use in emergency response and recovery operations are evaluated through on-site visual inspections of individual structures by teams of specially trained engineers or technicians; a process that is manpower-intensive, subjective, and slow. Specifically, the researcher was able to identify and evaluate strategies and procedures for using dynamic testing methods to rapidly …