Lateral Torsional Buckling Response In Glass Fiber Reinforced Polymer Composite Beams And Comparison With Ansys Modeling & Design Equations,
2015
West Virginia University
Lateral Torsional Buckling Response In Glass Fiber Reinforced Polymer Composite Beams And Comparison With Ansys Modeling & Design Equations, Santosh Vangala
Graduate Theses, Dissertations, and Problem Reports
Glass fiber reinforced polymer (GFRP) composites have the potential to replace the existing conventional materials in Civil Engineering like steel and concrete. Such potential can be attributed to the numerous advantages GFRP composites have over conventional materials. Some of the advantages are: high strength-to-weight ratio, corrosion resistance, low life cycle cost and maintenance, nonmagnetic and electronic transparency. As the application of GFRP is on the rise, the need for developing accurate design equations for these materials has been imperative. The GFRP composites are manufactured through pultrusion and although they have numerous advantages they are less stiff than similar profiles made …
First Steps In Developing Cement-Based Batteries To Power Cathodic Protection Of Embedded Steel In Concrete,
2015
Technological University Dublin
First Steps In Developing Cement-Based Batteries To Power Cathodic Protection Of Embedded Steel In Concrete, Niall Holmes, Aimee Byrne, Brian Norton
Articles
This paper presents the first steps in developing innovative cement-based batteries to power cathodic protection in reinforced concrete structures. Initial electrical outputs of 1.55V and 23mA have been found to be sufficient to polarise prescribed corrosion currents of 20mA per m2 of embedded steel. Cathodic protection is a well-developed and powerful technique to limit the effects of steel reinforcement corrosion. However, as it requires an electrical supply day and night, it is often powered by non-environmentally friendly diesel generators or connected to the electrical grid. This paper focuses on increasing the ionic conductivity of the solution in the cement pores, …
Identifying And Modelling Permit Trucks For Bridge Loading,
2015
Technological University Dublin
Identifying And Modelling Permit Trucks For Bridge Loading, Bernard Enright, Eugene J. Obrien, Cathal Leahy
Articles
Accurate estimates of characteristic traffic load effects are essential in order to optimize bridge safety assessment. Permit trucks dominate the extreme upper tail of the truck loading distribution and as a result need careful examination. This paper proposes rules for filtering these trucks from Weigh-In-Motion data for both the US and Europe. The importance of these trucks in critical bridge loading events is then examined for both regions. A Monte Carlo traffic simulation model is developed which focuses on the accurate simulation of permit trucks.
Nonlinear Analysis Of Isotropic Slab Bridges Under Extreme Traffic Loading,
2015
University College Dublin
Nonlinear Analysis Of Isotropic Slab Bridges Under Extreme Traffic Loading, Donya Hajializadeh, A. Salam Al-Sabah, Eugene J. Obrien, Debra F. Laefer, Bernard Enright
Articles
Probabilistic analysis of traffic loading on a bridge traditionally involves an extrapolation from measured or simulated load effects to a characteristic maximum value. In recent years, Long Run Simulation, whereby thousands of years of traffic are simulated, has allowed researchers to gain new insights into the nature of the traffic scenarios that govern at the limit state. For example, mobile cranes and low-loaders, sometimes accompanied by a common articulated truck, have been shown to govern in most cases. In this paper, the extreme loading scenarios identified in the Long Run Simulation are applied to a non-linear, two-dimensional (2D) plate finite …
Spatial Time-Dependent Reliability Analysis Of Reinforced Concrete Slab Bridges Subject To Realistic Traffic Loading,
2015
University College Dublin
Spatial Time-Dependent Reliability Analysis Of Reinforced Concrete Slab Bridges Subject To Realistic Traffic Loading, Donya Hajializadeh, Mark Stewart, Bernard Enright, Eugene J. Obrien
Articles
Resistance and loads are often correlated in time and space. The paper assesses the influence of these correlations on structural reliability/probability of failure for a typical two-lane RC slab bridge under realistic traffic loading. Spatial variables for structural resistance are cover and concrete compressive strength, which in turn affect the strength and chloride-induced corrosion of RC elements. Random variables include pit depth and model error. Correlation of weights between trucks in adjacent lanes and inter-vehicle gaps are also included and are calibrated against Weigh-In-Motion (WIM) data. Reliability analysis of deteriorating bridges needs to incorporate uncertainties associated with parameters governing the …
Prediction Of Load Capacity Variation In Frp Bonded Concrete Specimens Using Brownian Motion,
2015
Marquette University
Prediction Of Load Capacity Variation In Frp Bonded Concrete Specimens Using Brownian Motion, Tayyebeh Mohammadi, Baolin Wan, Jian-Guo Dai, Chao Zhu
Civil and Environmental Engineering Faculty Research and Publications
In wet lay-up process, dry fiber sheets are saturated with a polymer and applied to the concrete surface by hand. This causes relatively large variation in properties of the cured FRP composite material. It is hard to know the exact mechanical properties of the FRP constructed by wet lay-up process. In addition, the stiffness of FRP changes during debonding process due to different amount of concrete attached to the debonded FRP at different locations. It is also inevitable to have considerable variations in the strength of concrete. Therefore, the behaviour of FRP bonded concrete members varies among specimens even when …
Performance Evaluations Of Pavement Working Platforms Constructed With Large-Sized Unconventional Aggregates,
2015
University of Illinois at Urbana-Champaign
Performance Evaluations Of Pavement Working Platforms Constructed With Large-Sized Unconventional Aggregates, Hasan Kazmee, Erol Tutumluer, Debakanta Mishra
Civil Engineering Faculty Publications and Presentations
With recent focus on sustainable construction practices and the ever-increasing transportation cost and scarcity of natural resources, use of unconventional aggregate materials, such as primary crusher run and concrete demolition waste, have become viable for the construction of pavement working platforms over very weak and often wet subgrade soils. To this end, a research study was undertaken at the Illinois Center for Transportation to evaluate the adequacy and field performances of such large-sized aggregate materials and validate new material specifications. A state-of-the-art image analysis technique was utilized to characterize the size and morphological properties, e.g. shape, texture and angularity of …
Introductory Editorial: Water Microbiology,
2015
Marquette University
Introductory Editorial: Water Microbiology, Patrick J. Mcnamara, Mark J. Krzmarzick
Civil and Environmental Engineering Faculty Research and Publications
No abstract provided.
Determining Soil Erosion With Varying Corn Stover Cover Factors,
2015
University of Kentucky
Determining Soil Erosion With Varying Corn Stover Cover Factors, Nicole K. Koeninger
Theses and Dissertations--Biosystems and Agricultural Engineering
Since the Dust Bowl, conservation agriculture has become a common practice globally. Because of the rising interest in the use of corn biomass as a feedstock for biofuel production, the effects of corn stover removal on soil erosion were explored. It was hypothesized that selective harvesting strategies would impact soil erosion differently across a variety of slopes. Soil erosion boxes were constructed, and a rainfall simulator with an intensity of 30 mm hr-1 for 46 min was used to create runoff from slopes of 1, 5, and 10% and three cover factor treatments (no removal and two simulated corn …
Development Of Techniques For Assessing And Restoring Streams On Surface Mined Lands,
2015
University of Kentucky
Development Of Techniques For Assessing And Restoring Streams On Surface Mined Lands, Whitney Cole Blackburn-Lynch
Theses and Dissertations--Biosystems and Agricultural Engineering
Surface mining is a commonly used method for extracting coal in the Appalachian Coalfields of the U.S. This mining practice produces excess spoil or overburden, which is often placed in adjacent valleys resulting in the creation of valley fills. These valley fills bury headwater streams, which in turn can negatively impact downstream ecosystems. In 2008, the University of Kentucky designed and constructed 1,020 m of ephemeral, intermittent and headwater streams on an existing valley fill (Guy Cove) as a proof-of-concept. The goal of the project was to evaluate whether or not a stream recreation could occur on mined lands, particularly …
The Impact Of Capsid Proteins On Virus Removal And Inactivation During Water Treatment Processes,
2015
Marquette University
The Impact Of Capsid Proteins On Virus Removal And Inactivation During Water Treatment Processes, Brooke K. Mayer, Yu Yang, Daniel Gerrity, Morteza A. Abbaszadegan
Civil and Environmental Engineering Faculty Research and Publications
This study examined the effect of the amino acid composition of protein capsids on virus inactivation using ultraviolet (UV) irradiation and titanium dioxide photocatalysis, and physical removal via enhanced coagulation using ferric chloride. Although genomic damage is likely more extensive than protein damage for viruses treated using UV, proteins are still substantially degraded. All amino acids demonstrated significant correlations with UV susceptibility. The hydroxyl radicals produced during photocatalysis are considered nonspecific, but they likely cause greater overall damage to virus capsid proteins relative to the genome. Oxidizing chemicals, including hydroxyl radicals, preferentially degrade amino acids over nucleotides, and the amino …
Flowability And Density Characteristics Of Controlled Low Strength Material (Clsm) Using Native High Plasticity Clay,
2015
University of Texas at Arlington
Flowability And Density Characteristics Of Controlled Low Strength Material (Clsm) Using Native High Plasticity Clay, Anand J. Puppala, Bhaskar Chittoori, Anil Raavi
Civil Engineering Faculty Publications and Presentations
In pipeline construction projects when high plastic clayey soils are encountered in the excavated trench material, they are typically landfilled and better quality materials are imported from outside quarry sources for use as bedding and haunch zone materials. This practice has detrimental environmental and cost impacts; therefore, an efficient reutilization of this high plastic excavated material to produce controlled low strength materials (CLSMs) to use as bedding and haunch zone materials will have major sustainability benefits. As a part of an on-going research study, novel CLSM mix designs were developed by utilizing native high plastic clayey soils from the excavated …
Shear Capacity Of Rc Beams At Elevated Temperatures,
2015
Western University
Shear Capacity Of Rc Beams At Elevated Temperatures, Maged A. Youssef, Mohamed Diab, Salah El-Din F. El-Fitiany
Civil and Environmental Engineering Publications
Fire safety is a critical criterion for designing reinforced concrete structures. With the introduction of performance-based design, structural engineers need design tools to assess the capacity of different elements during fire exposure. This paper proposes an analytical method to predict the shear capacity of reinforced concrete beams exposed to elevated temperatures. The proposed method extends the use of existing ambient temperature methods by accounting for the effect of elevated temperatures on material properties. It involves heat transfer analysis, evaluation of the material properties at elevated temperatures, and application of the modified compression field theory to estimate the shear capacity. The …
Composite 1-Dimensional Modeling Of The Expanded Small Scale Mississippi River Model,
2015
Louisiana State University and Agricultural and Mechanical College
Composite 1-Dimensional Modeling Of The Expanded Small Scale Mississippi River Model, Benjamin Joseph Hartman
LSU Master's Theses
Stream wise 1-dimensional numerical modelling couples well with long term, large domain physical modelling because of its ability to perform simulations quickly. The downsides are limitations in replicating some complex hydrodynamics and sediment transport behavior. In this study, a 1-dimensional model of a section of the Expanded Small Scale Physical Model (ESSPM) is developed using the USACE HEC-RAS software with a goal of investigating the ability of a 1-dimensional model to accurately replicate hydraulics at ESSPM time scales. Additional simulations are conducted to examine the impact of varying distortion scales, non-frictional energy losses and synthetic sediment on hydraulic behavior. The …
Probabilistic Performance-Based Hurricane Engineering (Pbhe) Framework,
2015
Louisiana State University and Agricultural and Mechanical College
Probabilistic Performance-Based Hurricane Engineering (Pbhe) Framework, Vipin Unnithan Unnikrishnan
LSU Doctoral Dissertations
In modern times, hurricanes have caused enormous losses to the communities worldwide both in terms of property damage and loss of life. In light of these losses, a comprehensive methodology is required to improve the quantification of risk and the design of structures subject to hurricane hazard. This research develops a probabilistic Performance-Based Hurricane Engineering (PBHE) framework for hurricane risk assessment. The proposed PBHE is based on the total probability theorem, similar to the Performance-Based Earthquake Engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) Center, and to the Performance-Based Wind Engineering (PBWE) framework. The methodology presented in …
Applications Of Geopolymer In Civil Engineering: Feasibility Study Of Loess Stabilization And Waste Concrete Recycling,
2015
Louisiana State University and Agricultural and Mechanical College
Applications Of Geopolymer In Civil Engineering: Feasibility Study Of Loess Stabilization And Waste Concrete Recycling, Zhen Liu
LSU Doctoral Dissertations
The fast growing population and economic development have resulted in an increasing demand for residential and commercial buildings and infrastructures. However, there are problems identified to fulfill this demand, including that (1) problematic soils need to be treated/improved before the construction of building and infrastructures; (2) the Portland cement industry, which is used for concrete production and as the conventional soil stabilizer, is not environment friendly; (3) qualified natural aggregates for concrete production are being depleted; and (4) great amount of construction & demolition waste (C&D waste) is being produced every year. This means that green materials and recycling the …
Connected Vehicle Technology: User And System Performance Characteristics,
2015
Louisiana State University and Agricultural and Mechanical College
Connected Vehicle Technology: User And System Performance Characteristics, Osama Abdulmonaem Thabet Osman
LSU Doctoral Dissertations
The emerging connected vehicle (CV) technology plays a promising role in providing more operable and safer transportation environments. Yet, many questions remain unanswered as to how various user and system characteristics of CV-enabled networks can shape the successful implementation of the technology to maximize the return on investment. This research attempts to capture the effect of multiple factors such as traffic density, market penetration, and transmission range on the communication stability and overall network performance by developing a new CONnectivity ROBustness (CONROB) model. The model was tested with data collected from microscopic simulation of a 195 sq-mile traffic network and …
Investigating Wave Forces On Coastal Bridge Decks,
2015
Louisiana State University and Agricultural and Mechanical College
Investigating Wave Forces On Coastal Bridge Decks, Guoji Xu
LSU Doctoral Dissertations
Tsunamis and hurricane induced waves are responsible for many coastal bridge failures, especially in the last decade. In the current study, three countermeasures (reducing the entrapped air, elevating the structures and rigidifying the structures) are considered, two wave types (solitary wave theory and Stokes wave theory) are chosen, and two bridge types (single bridge deck and twin bridge decks) are taken into account. Parametric studies are conducted based on Computational Fluid Dynamics (CFD) software ANSYS Fluent. This dissertation comprises two broad themes according to the wave types adopted. The first one is to make a great effort to investigate solitary …
Coupled Gradient Enhanced Damage - Viscoplasticity Model Using Phase Field Method,
2015
Louisiana State University and Agricultural and Mechanical College
Coupled Gradient Enhanced Damage - Viscoplasticity Model Using Phase Field Method, Navid Mozaffari
LSU Doctoral Dissertations
The aim of this dissertation is developing a framework to describe damage evolution as a phase transformation in solid materials and couple it to the well-known Perzyna type viscoplastic model to account for inelastic behavior of ductile materials. To accomplish this task, the following steps have been performed. First, a new nonlocal, gradient based damage model is proposed for isotropic elastic damage using the phase field method in order to show the evolution of damage in brittle materials. The general framework of the phase field model (PFM) is discussed and the order parameter is related to the damage variable in …
Development And Optimization Of Non-Hydrostatic Models For Water Waves And Fluid-Vegetation Interaction,
2015
Louisiana State University and Agricultural and Mechanical College
Development And Optimization Of Non-Hydrostatic Models For Water Waves And Fluid-Vegetation Interaction, Ling Zhu
LSU Doctoral Dissertations
The primary objective of this study is twofold: 1) to develop an efficient and accurate non-hydrostatic wave model for fully dispersive highly nonlinear waves, and 2) to investigate the interaction between waves and submerged flexible vegetation using a fully coupled wave-vegetation model. This research consists of three parts. Firstly, an analytical dispersion relationship is derived for waves simulated by models utilizing Keller-box scheme and central differencing for vertical discretization. The phase speed can be expressed as a rational polynomial function of the dimensionless water depth, $kh$, and the layer distribution in water column becomes an optimizable parameter in this function. …
