Engineering Commons^™

Integration Of Hadfield Steel Into Modern Body Armor, Jason T. Fridlund

ME 4133/6133 Mechanical Metallurgy

The increased lethality of recently fielded projectiles mandates a proportional escalation in armor performance. Recent advancements in ceramic technologies have allowed designers to incorporate harder but more brittle materials into hard armor designs to defeat yet more capable penetrating projectiles. Ceramics suffer from the feature of shattering, however, even when impacted by threats below their design parameters. While this shattering mechanism is used effectively to dissipate energy from high-energy rifle projectiles, it is wasted on low-energy projectiles, and can result in easily damaged lifesaving gear, both of which are undesirable in combat. In contrast, steel body armor has been used …

Structural Performance Of Single-Skin Glass Façade Systems Exposed To Fire, Mohamed Badr, Maged A. Youssef, Salah El-Din F. El-Fitiany, Ajitanshu Vedrtnam

Civil and Environmental Engineering Publications

Purpose

Understanding the structural performance of external glass curtain walls (façades) during fire exposure is critical for the safety of the occupants, as their failure can lead to fire spread throughout the entire building. This concern is magnified by the recent increase in fire incidents and wildfires. This paper presents the first simplified technique to model single skin façades during fire exposure, and, then utilizes it to examine the structural behaviour of vertical, inclined, and oversized façade panels.

Design/methodology/approach

The proposed technique is based on conducting simplified heat transfer calculations, and, then utilizing a widely used structural analysis software to …

Dataset For Large-Scale, Lateral-Torsional Buckling Tests Of Continuous Beams In A Grillage System, Ahmed Rageh, C. Shawn Sun, Daniel G. Linzell, Jay A. Puckett

Department of Civil and Environmental Engineering: Faculty Publications

A number of large-scale tests of a grillage system are summarized and reduced data are provided. The tests were completed in association with a Louisiana Transportation Research Center (LTRC) project for the Louisiana Department of Transportation and Development (LA DOTD) whose goal was to better quantify behavior and limit states of steel bridge floor systems to refine longitudinal member (stringer) load- rating calculations. A number of tests focused on the behavior of the stringers resting on transverse members (a floorbeam), a system akin to a grillage. The system was proportioned with the expectation that stringer lateral-torsional buckling, a key steel …

Seismic Performance Comparison Of Ordinary Concentrically Braced Frames In The Western And Central United States, Matthew Waters

Master's Theses (2009 -)

Ordinary concentrically braced frames (OCBFs) are intended to be moderately ductile steel seismic-force-resisting systems and are permitted in low-rise buildings in regions with high seismic hazards. There has been relatively little research to quantify the seismic performance of OCBFs, with most of the previous work emphasizing the role of reserve capacity on performance. To improve the understanding of seismic performance and validate current design provisions, a series of nonlinear response-history analyses were conducted. Two, three-story OCBF study buildings were designed in accordance with ASCE/SEI 7-16 for sites in Seattle, WA and Memphis, TN; the sites have relatively high seismic hazards …

Characterization Of Hydrogen Embrittlement Sensitivity In High Hardness Steels, David Ahlen Salley

Theses and Dissertations

High hardness steels can be affected by delayed brittle cracking often attributed to hydrogen embrittlement. Improved resistance to hydrogen embrittlement would be beneficial to many industries including military, automotive, and high-rise construction. While other prevention methods include coating, trapping, and barriers, design efforts in this study were focused on improving intrinsic properties to be more resistant to hydrogen embrittlement. Four alloys targeting 477 – 534 HB were designed and produced in-house and compared against a commercial grade 500 HB alloy. Charpy V-notch (CVN) impact toughness and tensile specimens were made according to ASTM E23 and ASTM E8 to characterize mechanical …

Evaluating The Effects Of Shored Construction On Steel Girder Composite Bridges, Parker Brooks

Doctoral Dissertations and Master's Theses

Steel composite girder bridges provide economic advantages and higher load-carrying capacity than non-composite alternatives. Over the years, a conventional sequence of un-shored construction for steel girder composite bridges has been developed. There is an alternative construction sequence, known as shored construction, that uses temporary supports (discretely or fully supported) for the superstructure during the installation of metal forms and the pouring of concrete. Shored construction also can be used in an Accelerated Bridge Construction (ABC) practice where construction occurs at a nearby site and fully-formed elements are transported to the final site using self-propelled modular transporters (SPMTs). In order to …

Cold-Formed Steel Strength Predictions For Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum

Engineering Technology Faculty Publications

Locally slender open cross-section members are susceptible to significant twisting and high warping torsion stresses. Torsion considerations are complicated by whether it is derived as a first-order effect from loading or a second-order effect from instability. Previous direct torsion experiments on lipped channels have shown significant inelastic reserve in limited cases. The current design for combined bending and torsion interaction has some limitations, including only considering the first yield in torsion and ignoring the cross-section slenderness in torsion. A parametric study is conducted to predict the torsion capacity in locally slender cross-sections. Shell finite element models of lipped Cee and …

Strain And Temperature Measurement From Distributed Fiber Optic Sensors In Performance-Based Fire Engineering, Yanping Zhu

Doctoral Dissertations

"Strain and temperature measurement of steel and concrete structures under fires is critical to the understanding of structural performance yet historically challenging due to a significant gap in measurement science. This Ph.D. study characterizes in six parts low-cost distributed fiber optic sensors and applies them to strain, and temperature measurements based on Rayleigh and Brillouin light scattering. The first part aims to quantify the Rayleigh scattering based measurement accuracy of distributed fiber optic sensors under a heating-holding load protocol and characterize the effect of polymer coating on the sensors as the polymer softens and melts at elevated temperatures. The second …

A Comparison Of Common Structural Materials, Molly Green

Williams Honors College, Honors Research Projects

This report will compare structural steel, concrete, and lumber through the lenses of mechanical properties, design process, cost, and environmental impact. Steel is a versatile, strong, and lightweight material that comes at a premium price – both financially and environmentally. It is the most expensive material of the three included in this report. This is largely due to its complex manufacturing process that is also responsible for a significant amount of the world’s carbon dioxide emissions. Concrete is significantly less expensive than steel, but the carbon dioxide emissions from manufacturing are approximately equal. Concrete also only performs well in compression …

Austenitic, Duplex, And Lean Duplex Stainless Steel Critical Pitting Temperature In Simulated Concrete Environment, Bobby Giebel

Williams Honors College, Honors Research Projects

In this work, the critical pitting temperature (CPT) will be observed for a selection of austenitic (316LN and 24100) and duplex (2205), and lean duplex (2304, 2001) stainless steels in simulated concrete pore solution. To study the influence of temperature on the pitting stability of the stainless steels, three temperatures were tested: 25oC, 45oC, and 65oC for cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS). Electrochemical properties of the interfaces we studied via EIS analysis. Kinetics were studied via CPP testing. To reveal the critical pitting temperature of the stainless steels, cyclic thermammetry was used. Characterization of the pits …