Structural Engineering Commons^™

Structural Health Monitoring Of Composite Overwrapped Pressure Vessels, Luca Letizia

Honors Undergraduate Theses

This work is focusing to study the structural behavior of Composite Overwrapped Pressure Vessels (COPVs). These COPVs are found in many engineering applications. In the aerospace field, they are installed onto spaceships and aid the reorientation of the spacecraft in very far and airless, therefore frictionless, orbits to save energy and fuel. The intent of this research is to analyze the difference in performance of both perfectly intact and purposely damaged tanks. Understanding both the source and location of a structural fault will help NASA engineers predict the performance of COPVs subject to similar conditions, which could prevent failures of …

Sinkhole Monitoring Using Groundwater Table Data, Ton Tu

Electronic Theses and Dissertations

Florida might be one of the most sinkhole-active areas on the earth. Due to its unpredictability and significance of occurrence, the development of sinkhole monitoring techniques is imperative to minimize sinkhole-induced hazards. Several methods have been used to evaluate sinkhole risks, including destructive methods, such as Standard Penetrating Tests (SPT) and Cone Penetrating Tests (CPT), geophysical method, and sensor-based groundwater monitoring method. However, few studies are available for comprehensive understanding of spatiotemporal sinkhole mechanism by combining different exploration methods under realistic experimental conditions. The objective of this study is to understand spatiotemporal sinkhole mechanism, using SPT, CPT, ground penetrating radar …

Heterogeneous Thermal Effects On Structural-Grade Steel, Eric Wickersham

Williams Honors College, Honors Research Projects

The AISC Steel Construction Manual covers structural steel design while at atmospheric and elevated temperatures. The manual does not, though, cover what happens to the steel after it has cooled from elevated temperatures. To fill in this knowledge gap, A36 steel was studied with respect to three main criteria: time, temperature, and cooling. Time was sub-divided into a standard burn (17-20min) and a prolonged burn (90min). Temperature was sub-divided into an average burn (600-800⁰F) and an extreme burn (>1200⁰F). To reach such temperatures, a forge was constructed and used during the burning process. Cooling was sub-divided into standard (air …

An Exploration Of Structural Timber Innovation, Simon Beskitt

Williams Honors College, Honors Research Projects

In many undergraduate programs of study, civil and structural engineering students are exposed to introductory material regarding timber construction. The information received in the undergraduate experience typically consists of a brief summary of the basic mechanical properties of wood but does not significantly cover timber design. Much greater emphasis is placed on design practices involving steel and concrete, likely due to their prominence in contemporary building trends in civil engineering. While it is true that wood is one of the older materials in terms of its utilization in structural and architectural design, it is certainly not an antiquated choice. Wood …

Corrosion Protection Systems In Offshore Structures, Hristo Ivanov

Williams Honors College, Honors Research Projects

Corrosion plays a pivotal role in the engineering world. Engineers of all disciplines must consider the dangers that this phenomenon can incur. Interestingly, corrosion mitigation is not a topic that is addressed in most academic curricula. The goal of this paper is to give engineering students a brief introduction into corrosion and some of the prevention techniques commonly used today.

The design of a corrosion protection system for offshore structures is discussed in order to illustrate how these techniques can be utilized even in the most extreme environments. First, the driving force behind corrosion is examined, introducing the basic mechanics …

Effect Of Fiber Orientation On Dynamic Compressive Properties Of An Ultra-High Performance Concrete, Andrew B. Groeneveld

Dissertations, Master's Theses and Master's Reports

Casting structural elements with ultra-high performance concrete (UHPC) tends to create preferential fiber alignment, which affects the strength and must be accounted for in design. Fiber orientation effects in tension have been studied extensively, but less work has been performed for compression. This work characterizes the fiber orientation occurring in a typical UHPC beam and how that orientation affects compressive behavior at high strain rates. Specimens (36 total) were cored from the beam and their fiber orientations were non-destructively evaluated using x-ray computed tomography (CT). Fibers showed flow-induced alignment along the length of the beam, with orientation angles in the …

Probability-Based Hurricane Resilience Evaluation And Retrofitting For Residential Community, Yadong Dong

Dissertations, Master's Theses and Master's Reports

Wood residential construction is vulnerable to hurricanes, as evident in recent hurricane events. Many studies indicated that the changing climate may very likely alter hurricane patterns, which could lead to more severe hurricane damage to the wood residential construction that accounts for 90% of the residence in the USA. On the other hand, deterioration of material increases the chance of structural failure by reducing the structural capacity (e.g., corrosion of fasteners in roof panel could significantly reduce the withdrawal capacity of the roofing structure during hurricane events).

Currently, most hurricane damage estimations only focus on direct loss (e.g., structural loss). …

Structural Control Of Wind Turbines With Soil Structure Interaction Included, Breiffni Fitzgerald, Biswajit Basu

Articles

The importance of considering soil structure interaction in structural control of wind turbines is investigated in this paper. An Euler–Lagrangian wind turbine mathematical model based on an energy formulation was developed for this purpose which considers the structural dynamics of the system and the interaction between in-plane and out-of-plane blade vibrations. Also, the interaction between the blades and the tower including a tuned mass damper (TMD) is considered. The turbine is subject to turbulent aerodynamic loading simulated using a modification to the classic Blade Element Momentum (BEM) theory with turbulence generated from rotationally sampled spectra. The turbine is also subject …

An Overview Of The Development Of Cement-Based Batteries For The Cathodic Protection Of Embedded Steel In Concrete, Aimee Byrne, Niall Holmes, Brian Norton

Conference papers

This paper presents an overview of the cement-based batteries developed in DIT for use in the cathodic protection of embedded steel in reinforced concrete undergoing chloride-induced corrosion. Cathodic protection delivers an external current (approximately 20mA per m2 of embedded steel) which effectively polarises the internal current generated during corrosion. The batteries developed in DIT comprise of a cement-based electrolyte containing different additives including sand, aggregate, salts, carbon black and plasticiser with protruding anode and cathode metal plates. These batteries produced an initial electrical output of 1.5V and 23mA through a 10 resistor as measured using data acquisition units and a …

Risk-Based Assessment And Strengthening Of Electric Power Systems Subjected To Natural Hazards, Abdullahi Salman

Dissertations, Master's Theses and Master's Reports

Modern economic and social activities are dependent on a complex network of infrastructure systems that are highly interdependent. Electric power systems form the backbone of such complex network as most civil infrastructure systems cannot function properly without reliable power supply. Electric power systems are vulnerable to extensive damage due to natural hazards, as evident in recent hazard events. Hurricanes, earthquakes, floods, tornados and other natural hazards have caused billions of dollars in direct losses due to damage to power systems and indirect losses due to power outages, as well as social disruption. There is, therefore, a need for a comprehensive …