Engineering Commons^™

Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari

Electronic Theses and Dissertations

Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Wake Characteristics Of Wall-Mounted Finite Solid And Foam-Covered Cylinders, Subhadip Das

Electronic Theses and Dissertations

The wake characteristics of a wall-mounted finite foam-covered cylinder are explored by comparing the flow properties with the wake of a solid cylinder. The velocity data are acquired experimentally using planar particle image velocimetry (PIV) and numerically by large eddy simulation at Reynolds number of 35100 based on the flow depth and 13100 based on the cylinder diameter. The wake characteristics may vary significantly if the approach flow properties change and also depend on the relative height of the boundary layer thickness with respect to the cylinder height. Therefore, it is a necessity to achieve a fully developed approach flow …

Methods Of Determining And Predicating Community Annoyance Due To Aircraft Noise, Kevin Zielinski

Electronic Theses and Dissertations

As the importance of the aviation industry continues to grow, airports continue to expand, andincrease operations; noise generated from aircraft is becoming a growing concern to people livingwithin the communities surrounding the airports. Community members have shown concern throughcomplaints and annoyance due to the disturbances that aircraft noise cause in their everyday life. Thepurpose of this study is to determine which factors most affect community annoyance towards aircraftnoise. There are two main factors to be considered when analyzing annoyance due to aircraft noise.The first is the acoustic factors caused by the aircrafts themselves, such as the noise the aircraft emitsor …

Structural Performance Of Shelf Angle Connection With Innovative Detailing, Shivam Sharma

Electronic Theses and Dissertations

Recent legislations are demanding more efficient thermal insulation of the building envelopes. However, most of the energy used for heating is lost through openings and small air gaps resulting from various penetrations of highly conductive elements through the building envelope. These thermal bridges can also give rise to mould growth and condensation problems. One such example is the anchoring of shelf angles to the load bearing structures, as they have to cut through the exterior insulation used to enhance the thermal performance of a building envelope.

Steel through-bolts have been conventionally used by the construction industry to anchor shelf angles …

Finite Element Analysis Of Complex Vectorbloc Beam-Column Connections, Labiba Kalem

Electronic Theses and Dissertations

Steel modular construction provides an efficient alternative to traditional construction practices. A key component to modular construction is the connection between the individual modules, which hold the building together against applied loads such as gravity, snow, and wind. The VectorBloc connector is an innovative cast steel connector that is used in the connections between steel modules made from hollow structural steel (HSS) members. The current VectorBloc connector, called VB4, is limited in its uplift capacity and thus faces challenges when applied to structures facing high uplift forces. Thus, a new design of the VectorBloc connector, called VB6, with a focus …

An Enhanced Framework To Compute Road User Costs Associated With Construction Zones, Jeremiah Adebiyi

Electronic Theses and Dissertations

The monetary quantification of inconveniences caused to the road users by ongoing construction activities is known as the Road Users Costs (RUCs). While the importance of RUCs is widely known, some highway agencies lack an appropriate methodology to compute RUCs. Thus, there is a need to develop a framework to compute RUCs that can be adopted quickly by highway agencies. This study reviewed existing literature and conducted a nationwide survey to identify and summarize the current practices of computing RUCs. It developed an enhanced framework and tool to compute RUCs that balances the effort required to calculate RUCs and the …

Develop A Multi-Functional Green Pervious Concrete (Mgpc) Pavement With Polycyclic Aromatic Hydrocarbons (Pahs) Removal Function., Hong Shang

Electronic Theses and Dissertations

Stormwater runoff induced Polycyclic Aromatic Hydrocarbons (PAHs) contaminant increasingly imperils the groundwater quality and the sustainable development of human society due to the potential carcinogenic risks. Pavement can be considered as the first line of defense for contaminant removal of the stormwater runoff. New construction materials with stormwater runoff quantity and quality control are in urgent demand for updating the existing pavement system. An innovative material called Multi-functional Green Pervious Concrete (MGPC) was developed in the department of Civil and Environmental Engineering at University of Louisville. This material uses organoclay as the amendment to enhance the PAHs removal capacity of …

Wind Tunnel Study Of Wind-Induced Loads On Building Balconies, Tingzhou Tong

Electronic Theses and Dissertations

The wind-induced pressure coefficients for the balcony guardrail design are based on the provision of wall cladding and components provided in building codes, such as the National Building Code of Canada 2015. However, the balcony guard’s failure frequently occurred, which caused a number of accidents and casualties in the past years. This work studies the wind-induced pressure coefficients on the two typical balconies guard models, an isolated balcony and a continuous balcony, based on various wind direction, wind speeds, and balcony configurations through wind tunnel test. The test results in the wind tunnel are compared with the provisions of the …

Hydrodynamic Impacts Of Expanding Aquaculture, Zhilong Liu

Electronic Theses and Dissertations

Climate change may potentially change aquatic systems and bring certain risks for aquaculture development. Understanding interactions between aquaculture and the environment helps to ensure aquaculture expansion is sustainable in the future. It is critical to determine how farms influence tidal flow patterns, turbulence, mixing and material transport in estuaries. This research aims to determine the flow response of an oyster farm, predict how expanding farms and farm placement will alter estuarine dynamics, and understand how the design of a farm influences material transport.

The hydrodynamic response of a floating oyster aquaculture farm in a low inflow estuary (the Damariscotta River …

Understanding Hydrologic Risk Within The Context Of Climate Variability And Atmospheric Moisture Pathways, Ali Aljoda

Electronic Theses and Dissertations

Nonstationarity in the means and extremes of water resources (e.g., streamflow) due to climate change presents challenges to water resources management and planning. Changes in hydrologic variables such as streamflow critically impact infrastructure, water use planning and adaptation strategies, and can lead to increased societal vulnerability. As such, existing water resources infrastructure designed based on limited records of historical flow may deteriorate under future hydro-climatic changes. Thus, important scientific tasks are: a) examining and redefining the risk, reliability, and return periods under nonstationary conditions, b) understanding the changes in extreme events statistics (i.e. frequency, and magnitude), and c) linking these …

Evaluation Of Conventional Energy Conservation Strategies And Active Thermal Insulation Wall System And Economic Analyses., Li Liu

Electronic Theses and Dissertations

For the past few decades, the importance and the technology of building energy conservation is increasing. In support of this research into energy efficiency, the Department of Energy has developed simulation models of sixteen buildings representing most commercial buildings in the US. In this research, four of these sixteen prototype models were used in energy conservation analyses variety of energy conservation strategies in the seven US Climate Zones. To estimate the effectiveness of several common energy conservation measures on yearly building energy use, holistic analyses were conducted using software that accounts for the interactions of the building systems, occupants and …

Urban Arterial Lane Flow Distribution: A Before And After Traffic Microsimulation Analysis On The Effect Of Implementing New Route Markings And Signage., Larry Michael Summers

Electronic Theses and Dissertations

Urban arterials may not effectively utilize available lanes to move vehicles efficiently as drivers try to establish position along the corridor. This study evaluates lane flow distribution before and after implementing new route markings and overhead signs to utilize existing lanes better. A cellphone-based traffic data service called StreetLight gathered the traffic data used to establish the VISSIM model parameters for simulating current and projected conditions. This study shows that the lane assignment signage and route markers affected the lane flow distribution in the simulation. The simulation indicated the existing condition had average queue lengths of 320.6 meters, average travel …

Nitrate And Phosphate Removal From Denitrification Bioreactors Using Woodchips, Steel Chips And Agricultural Residue Media, Abdoul Aziz Kouanda

Electronic Theses and Dissertations

Nitrate and phosphate present in agricultural subsurface drainage water can impact surface water quality thus impacting the environment and human health by causing eutrophication and Methemoglobinemia in young infant. Biological denitrification and phosphate adsorption filters are treatments options that can help reduce nitrate and phosphate concentration from agricultural subsurface drainage before it can be discharged in surface water. The first objective of this dissertation was to determine the Michaelis-Menten kinetics model parameters for nitrate removal in bioreactors using the fresh, aged, and composted woodchips. The composted woodchips achieved a denitrification rate 2.4 times higher than the fresh woodchips which was …

Mechanically Spliced Precast Bridge Columns, Ted Sjurseth

Electronic Theses and Dissertations

Mechanical bar splices provide an alternative to the traditional method of lap splicing to achieve reinforcement bar continuity in reinforced concrete. Even though mechanical bar splices can be used as new precast column connections to accelerate the bridge construction (ABC), The use of bar couplers in the plastic hinge region of bridge columns is prohibited by the current US codes since the effects of bar couplers on the seismic behavior of columns is not fully investigated. A bridge column including precast columns with couplers located in a high seismic region must be designed to handle large inelastic lateral deformations. The …

Forecasting Geotechnical Parameters From Electrical Resistivity And Seismic Wave Velocities Using Artificial Neural Network Models, Fatema Tuz Johora

Electronic Theses and Dissertations

Geotechnical measurements of soil parameters used in the design of infrastructure provide information at a specific point of the ground. The use of limited point data may result in greater uncertainty and less reliability in design. Geophysical methods are non-invasive, less time-consuming, and provide continuous spatial information about the soil. However, geophysical information is not in terms of engineering parameters. Correlations between geotechnical parameters and geophysical parameters are needed to facilitate the use of geophysical information in geotechnical designs. The current research is focused on two geophysical methods; electrical resistivity (ER) and seismic wave velocity (S-wave and P-wave). Artificial neural …

Computational Modeling Of Climate Attributes And Condition Deterioration Of Concrete Highway Pavements, Salma Sultana

Electronic Theses and Dissertations

An efficient and safe road network secures the nation’s economy and prosperity by providing public mobility and freight transport. Maintenance and rehabilitation of the road network cost billions of dollars annually. Road and highway infrastructures performance in any country is impacted by load repetitions and it is further compromised by climate attributes and extreme weather events. Damages to roads and bridges are among the infrastructure failures that have occurred during these extreme events. If maintenance and rehabilitation are not done promptly, the damages to the road caused by heavy traffic and extreme climate may lead to life-threatening conditions for road …

New Longitudinal Error Balancing Approaches For Closed Traverses, Jose L. Manzano

Electronic Theses and Dissertations

This study presents two novel approaches to balance the horizontal longitudinal error of closure, E_C, in closed polygonal traverses. The standard procedure to balance E_C is the Compass Rule. This technique reduces E_C to zero by applying corrections in the lengths of all traverse sides. Those corrections are proportional to the corresponding side lengths. That is, this approach is not an error-correcting approach, but an error-balancing procedure.

The proposed new techniques are based on sensitivity analysis of E_C with respect to small variations, Δ_i, in the lengths of all sides i = 1, …

Seismic Performance Of Mechanically Spliced Precast Bridge Columns With New Couplers, Evan Greeneway

Electronic Theses and Dissertations

Lap splicing is not always the most economical or practical approach to achieve reinforcement bar continuity. Mechanical bar splices, or bar couplers, are one alternative that may be far more practical. Currently, the US codes do not allow for the use of bar couplers in the plastic hinge region for RC members in areas of high seismic activity. There has not been enough research into the couplers behavior when subjected to significant inelastic lateral deformations. The Lohr Structures Laboratory was used to conduct an experimental study on campus of South Dakota State University to evaluate the seismic performance of mechanically …

Effectiveness Of Seismic Bearings On A Typical Isolated Two-Column Rc Bridge Pier Located In North Mississippi, Hemant Raj Joshi

Electronic Theses and Dissertations

The 2020 ASCE infrastructure report card has assigned a letter grade of D- for bridges in Mississippi based on poor to fair condition ratings with many approaching the end of their useful service lives. Bridges in northern Mississippi lie up to 100 miles from the New Madrid Fault and fall into the Region 3 Seismic Performance Category defined by AASHTO. The primary objective of this study is to evaluate the performance of commercially available bridge bearings on a common bridge pier type used in northern MS under the combined action of superstructure gravity and lateral seismic loads. The use of …

Electromagnetic Survey Design Using Artifical Neural Networks, Shariful Islam Sharif

Electronic Theses and Dissertations

Acquiring geophysical information requires selection of the geophysical method based upon the defining physical property and a survey design with adequate resolution but cost effective based upon the size of the area to be surveyed. The objective of this study is to use artificial neural nets (ANNs) to design an optimal survey. The developed approach is tested for the case of soil pipe surveying using electromagnetics. Soil pipes are tortuous voids located within 1.5 m depth of the ground surface. They trend perpendicular to the slope and have cross-sectional dimensions on the order of millimeters to tens of centimeters. The …

A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague

Electronic Theses and Dissertations

Microplastics are an emerging concern due to their harmful effect to organisms and their ability to facilitate transport of contaminants including heavy metals. Microplastics can enter the environment through wastewater treatment plants, landfill leachate, and littering. Once in the environment microplastics can be distributed throughout rivers, the ocean, and lakes. In order to understand the adsorption of heavy metals to microplastics a geochemical modeling study was completed using Visual Minteq. Lab tests were completed to better understand what constituents are available in wastewater at four different locations: influent, clarifiers, digesters, and effluent. These constituents were then used to observe how …

Impact Of Blended Salt Anti-Icers/Deicers On Properties Of Asphalt Binders, Nurudeen A. Abidoye

Electronic Theses and Dissertations

Anyone who has ever attempted to remove a layer of ice from a roadway or sidewalk by plowing or shoveling knows it is no easy task when the ice is firmly bonded to the asphalt/concrete surface. Winter anti-icing/deicing operations are moral choices that mankind has made to combat winter storms. This research is aimed at evaluating the macro and nano structural impacts of (anti-icing/de-icing) salt on aged and unaged asphalt binders. The macro structural impacts focused on the rheological and creep properties, and the nano structural impacts focused on the surface topography, adhesion force, and modulus of asphalt binders. Rheological …

Current Status Of Design And Construction Of Piles With A Pilot Hole On Rock, Charles C. Crowner

Electronic Theses and Dissertations

Driven piles at project sites get their load bearing capacity from side friction along the driven lengths as well as from end resistance. Pilot holes is a pile driving assistance method used to aid driving displacement piles through hard/ dense layers and rock. These pilot holes can be a size smaller or larger than the pile that is to be installed. The pilot hole is first drilled down to a specific depth. The use of a pilot hole reduces the “end bearing” and “side resistance” within the drilled zone and aids the driving of the pile. This process also complicates …