Failure Investigation Of The Steel Strut Of Paseo Suspension Bridge, 2019 Missouri University of Science and Technology
Failure Investigation Of The Steel Strut Of Paseo Suspension Bridge, Genda Chen, Chris Courtright, Lokeswarappa R. Dharani, B. Xu
A vertical strut of the 1232-foot long, self-anchored Paseo Suspension Bridge fractured when the temperature hit at a record low of 9°F below zero. During inspection the following day, it was found that its lower pin was frozen and did not allow for free movement of the superstructure. The objective of this study is to pinpoint one of the four reasons for this incidence or their combination: overstressing, thermal contraction, fatigue, and reduction in fracture toughness at low temperatures. To achieve this objective, material property and fatigue testing was performed on samples of strut material while the bridge and ...
Heat Of Hydration Thermal Performance And Flexural Capacity Of Stainless-Steel Reinforced Concrete Sections, 2019 The University of Western Ontario
Heat Of Hydration Thermal Performance And Flexural Capacity Of Stainless-Steel Reinforced Concrete Sections, Mokhtar Khalifa
Electronic Thesis and Dissertation Repository
Stainless steel (SS) is increasingly used in the construction field due to its high strength and corrosion resistance. However, its coefficient of thermal expansion is different from that of concrete. This difference raises concerns about the potential for concrete cracking during the hydration process. To address this concern, a thermal-structural finite element model was developed to predict the stresses in SS reinforced concrete (RC) sections during the hydration process. Different curing regimes were taken into consideration. The analysis was performed in two stages. First, a transient thermal analysis was performed to determine the temperature distribution within the concrete section as ...
Perceptions Of Vulnerability To Flooding, Hurricanes, And Climate Change On Grand Isle, Louisiana’S Only Inhabited Barrier Island, Lauren Miller
Graduate Student Theses, Dissertations, & Professional Papers
This study used in-depth interviews of permanent residents on Grand Isle, Louisiana, a remote barrier island, to better understand their perceptions of structural flood measures, non-structural responses to flooding and hurricanes, and perceptions of vulnerability to flooding, hurricanes, and climate change on a remote barrier island-Grand Isle, Louisiana. Residents' perceptions regarding the various structural measures implemented by the federal, state, and local government appeared mixed. Non-structural responses to flooding risks implemented at the household, community, state, and federal level continue to strengthen resiliency on Grand Isle. According to interviewees, aspects of environmental, rural, and economic vulnerability on Grand Isle impact ...
In Situ Mechanical Characterization Of The Mixed- Mode Fracture Strength Of The Cu/Si Interface For Tsv Structures, 2019 Missouri University of Science and Technology
In Situ Mechanical Characterization Of The Mixed- Mode Fracture Strength Of The Cu/Si Interface For Tsv Structures, Chenglin Wu, Congjie Wei, Yanxiao Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In situ nanoindentation experiments have been widely adopted to characterize material behaviors of microelectronic devices. This work introduces the latest developments of nanoindentation experiments in the characterization of nonlinear material properties of 3D integrated microelectronic devices using the through-silicon via (TSV) technique. The elastic, plastic, and interfacial fracture behavior of the copper via and matrix via interface were characterized using small-scale specimens prepared with a focused ion beam (FIB) and nanoindentation experiments. A brittle interfacial fracture was found at the Cu/Si interface under mixed-mode loading with a phase angle ranging from 16.7° to 83.7°. The mixed-mode fracture ...
High Fidelity Modeling Of Cold-Formed Steel Single Lap Shear Screw Fastened Connections, 2019 University of Massachusetts Amherst
High Fidelity Modeling Of Cold-Formed Steel Single Lap Shear Screw Fastened Connections, Rita Kalo
Cold-formed steel connections are commonly fastened using self-tapping self-drilling screws. The behavior of these connections can differ based on the screw manufacturer or the cold-formed steel product used, both of which have a large selection available for use in industry. Because of their popularity and the many possible variations of these connections, researchers have frequently tested screw connections to characterize their behavior. However, repeatedly conducting this type of experiment is time consuming and expensive. Therefore, the purpose of this work was to create finite element models that can successfully predict the behavior of single lap shear screw connections, a common ...
Performance Of Concrete Tunnel Systems Subject To Fault Displacement, 2019 University of Massachusetts Amherst
Performance Of Concrete Tunnel Systems Subject To Fault Displacement, Michael Morano
A Finite Element Analysis (FEA) investigation of concrete tunnel systems traversing seismic faults is carried out to determine how to effectively mitigate the stresses induced in the liner when subject to fault displacement. A parametric study of various fault parameters, both in the damage zone and competent rock, is carried out to determine the site conditions which induce the most stress on the tunnel liner system. Results indicate that friction angle, cohesion, and elastic modulus of fault zones have varying effects on the stresses induced on the liner. The width of damage zone and expected displacements are also investigated and ...
Thin-Film Sensor For Fatigue Crack Sensing And Monitoring In Steel Bridges Under Varying Crack Propagation Rates And Random Traffic Loads, Xiangxiong Kong, Jian Li, Caroline Bennett, William Collins, Simon Laflamme, Hongki Jo
Civil, Construction and Environmental Engineering Publications
Fatigue cracks are critical structural concerns for steel highway bridges, and fatigue initiation and propagation activity continues undetected between physical bridge inspections. Monitoring fatigue crack activity between physical inspections can provide far greater reliability in structural performance and can be used to prevent excessive damage and repair costs. In this paper, a thin-film strain sensor, called a soft elastomeric capacitor (SEC) sensor, is evaluated for sensing and monitoring fatigue cracks in steel bridges. The SEC is a flexible and mechanically robust strain sensor, capable of monitoring strain over large structural surfaces. By deploying multiple SECs in the form of dense ...
A Multiline Anchor Concept For Floating Offshore Wind Turbines, 2019 University of Massachusetts Amherst
A Multiline Anchor Concept For Floating Offshore Wind Turbines, Casey Fontana
Floating offshore wind turbines (FOWTs) hold great potential for the renewable energy industry, but capital costs remain high. In efforts to increase FOWT substructure efficiency and reduce costs, this thesis investigates a novel multiline anchor concept in which FOWTs share anchors instead of being moored separately. The goal of this thesis is to evaluate the force dynamics, design, and potential cost reduction of the system. Anchor forces are simulated using the NREL 5 MW reference turbine and OC4-DeepCwind semisubmersible platform, and multiline anchor force is computed as the vector sum of the contributing mooring line tensions.
The use of a ...
The Effects Of Silica On The Properties Of Vitreous Enamels, 2018 Missouri University of Science and Technology
The Effects Of Silica On The Properties Of Vitreous Enamels, Signo Tadeu Dos Reis, Mike Koenigstein, Liang Fan, Genda Chen, Luka Pavic, Andrea Mogus-Milankovic
Materials Science and Engineering Faculty Research & Creative Works
Ground coat enamels for low carbon steel that contain silica as a mill addition have been developed to study the changes of their properties. Acid-resistant commercial enamel where silica addition was varied from 0 to 10.0 wt % was used for this investigation. The effects of the addition on the corrosion resistance, thermal properties, electrical properties, and mechanical adherence of the enamel to low carbon steel were studied. The corrosion resistance of the steel enameled coupons was tested using a salt spray (fog) apparatus for time periods reaching 168 h at room temperature. It was found that, although the density ...
Elevated Temperature Progressive Damage And Failure Of Duplex Stainless Steel, 2018 University of New Mexico - Main Campus
Elevated Temperature Progressive Damage And Failure Of Duplex Stainless Steel, Darren P. Luke
Civil Engineering ETDs
Ductile failure of metals has been the focus of research efforts within academia and industry for many years since it is tremendously important for understanding the failure of structures under extreme loading conditions. However, limited research has been dedicated to elevated temperature ductile failure, which is critical for evaluating catastrophic events such as industrial, structural or shipping vessel fires. A detailed investigation was conducted on the structural response of Duplex Stainless Steel at elevated temperatures. The temperature dependence of elastic modulus, yield strength, ultimate strength, and ductility was measured up to 1000°C and a continuum damage plasticity model was ...
Aversion And Warning Factors For Assessing Existing Reinforced Concrete Structures, 2018 The University of Western Ontario
Aversion And Warning Factors For Assessing Existing Reinforced Concrete Structures, Marcie Van Weerdhuizen
Electronic Thesis and Dissertation Repository
In a world of aging infrastructure, sustainability initiatives require additional investment in the assessment of existing reinforced concrete structures. Reliability-based assessment should minimize costs by reducing conservatism, while ensuring levels of safety equivalent to those for new designs. Current Canadian and US provisions assign target reliability levels for structural assessment based on criteria including occupancy type, expected failure behaviour, and the eect of element failure on the overall structural integrity. These criteria are defined using discrete and qualitative parameter values. It is shown that the true structural conditions can be better represented by verifying the applicability and completeness of these ...
Lessons Learned From Six Different Structural Health Monitoring Systems On Highway Bridges, 2018 University of Kentucky
Lessons Learned From Six Different Structural Health Monitoring Systems On Highway Bridges, Abheetha Peiris, Charlie Sun, Issam E. Harik
Kentucky Transportation Center Faculty and Researcher Publications
Structural health monitoring has been utilized in numerous ways to investigate the performance and integrity of highway bridges. This paper highlights the use of six structural health monitoring systems, which were deployed to monitor distinct behaviors on six bridges in Kentucky. The structural health monitoring systems are as follows: (1) Over-height truck impact detection and monitoring on the I-64 over US 60 bridge, (2) Barge impact detection and monitoring on northbound US 41 over the Ohio River, (3) effectiveness of carbon fiber-reinforced polymer retrofit evaluation based on prestressed concrete I-girder crack movement on the I-65 elevated expressway in Louisville, (4 ...
Epics Gaqt: Nandi Clean Kitchen Study, 2018 Purdue University
Epics Gaqt: Nandi Clean Kitchen Study, Yichen Fan
Engagement & Service-Learning Summit: Connecting Through Listening & Scholarship
No abstract provided.
Development Of Thermoplastic Composite Reinforced Ultra-High Performance Concrete Panels For Impact Resistance, Reagan M. Smith Gillis
Electronic Theses and Dissertations
Recent studies investigating the impact performance of ultra-high performance concrete (UHPC) reported a quasi-brittle flexural failure that transitioned to a brittle punching-shear failure as the size of the impact head was reduced. A potential technology to increase the flexural strength and impact resistance of concrete is applying fiber reinforced polymer (FRP) composites to the exterior faces of the beam or slab. In this work, E-glass fiber reinforced thermoplastics were utilized in two different systems to apply reinforcement to UHPC. Thermoplastic materials were chosen over traditional thermoset materials for their unique advantages, such as rapid fabrication, automated manufacturing and the ability ...
A Threshold To Utilize Guayule Resin As A New Binder In Flexible Pavement Industry, 2018 Missouri University of Science and Technology
A Threshold To Utilize Guayule Resin As A New Binder In Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study denotes a threshold to utilize Guayule Resin as a new bio-based binder or asphalt cement (AC) proportion, both with/out crumb rubber modifier (CRM), regarding solutions for environment, cost, and sustainability aspects. Via this research, 15 designated binders will be presented, all of them were tested as unaged and RTFO, whereas eight binders proceeded with PAV. Superpave was utilized to study their physical properties. Viscosity was examined upon some guayule-based binders with/out CRM, getting 114cP (at 135℃) for BGR, increased to about 3 times with 10%CRM (by weight of liquid binder) and about 7-8 times with ...
Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., 2018 University of Arkansas, Fayetteville
Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez
Civil Engineering Undergraduate Honors Theses
The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain ...
Automation Of Post-Earthquake Civil Infrastructure Reconnaissance, 2018 California Polytechnic State University, San Luis Obispo
Automation Of Post-Earthquake Civil Infrastructure Reconnaissance, Jack Bergquist
Traditionally post-earthquake structural engineering reconnaissance consists of a team of experts who are deployed to the field to record and capture earthquake damage data, which is later uploaded into online repositories. Despite many advances to these data archives in recent years, the entries in online repositories often have limited metadata which make it difficult and time consuming to extract specific damage evidence that can be used for meaningful analysis. This report outlines the author’s contributions to overcoming these challenges via the development of a neural network that automatically filters and classifies post-earthquake civil infrastructure damage data after a seismic ...
Evaluation Of Deformable Posts In The Zoi And Rigid Posts In Stiff Soil, 2018 University of Nebraska - Lincoln
Evaluation Of Deformable Posts In The Zoi And Rigid Posts In Stiff Soil, Thomas Ammon
Engineering Mechanics Dissertations & Theses
Debris fences are commonly used by states, in conjunction with a concrete parapet, to protect railway tracks. Their use limits the intrusion of debris that could damage tracks or clutter rail lines. Due to a lack of previously crash-tested systems, the safety performance of such designs are largely unknown. The Iowa Department of Transportation (DOT) desired that researchers at the Midwest Roadside Safety Facility (MwRSF) design a crashworthy debris fence mounted on top of a concrete parapet to meet the Manual for Assessing Safety Hardware (MASH) TL-3 crash test conditions. Part 1 of this thesis details the literature review and ...
The Live Load Response Of The Open Web Steel Joist Black Slough Bridge, 2018 Utah State University
The Live Load Response Of The Open Web Steel Joist Black Slough Bridge, Piero Caputo
All Graduate Plan B and other Reports
The bridge being studied spans the Black Slough River in the Nucor/Vulcraft facilities near Brigham City, Utah. The bridge is composed of seven heavyweight open web steel joists supporting a concrete deck-slab element and sitting in two concrete cantilever walls serving as bearings. A full-scale live-load test was performed using forklift vehicles at four locations on the deck. During the test, axial strains, deflections, and rotations where measured.
In their provisions, the American Association of State Highway and Transportation Officials (AASHTO) included a simplified number of equations and solutions used to calculate GDFs for standardized decks supported by beam ...
On The Development Of 8,000 Psi Geopolymer Mortar For Practical Use In Field Applications, 2018 University of Arkansas, Fayetteville
On The Development Of 8,000 Psi Geopolymer Mortar For Practical Use In Field Applications, Remington Gabriel Reed
Theses and Dissertations
Although there are several perceived benefits from the use of geopolymer binder as an alternative to ordinary portland cement in concrete materials, it is not widely used in field applications. Geopolymer materials have no set guidelines for mixture design and often require heat curing to facilitate strength gain. Additionally, many geopolymers are created using carefully controlled and high quality materials and activator chemicals. These factors greatly affect the practicality of the material. The goal of this research was to create a geopolymer material capable of achieving high compressive strengths at 28 days without heat curing, and using only readily available ...