Engineering Commons^™

Computationally Modeling The Human-Structure Interaction Response Of An Occupied Cantilevered Structure, Brennan Smith

Honors Theses

There is a limited understanding of the impact that passive human occupants have on a dynamic structural system, referred to as Human-Structure Interaction (HSI). Cantilevers are naturally prone to excessive vibrations due to their long unsupported spans, and cantilevered structures such as those commonly found in the seating area of a stadium facility or concert hall are designed to support a high density of occupancy.

This study determined that HSI in cantilevered structures can be modeled using a simple two-degree-of-freedom system. The results of the model were validated by data that was collected on a small-scale laboratory structure intentionally designed …

Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis

All Theses

Rising popularity in mass timber construction for residential and commercial projects has escalated the need to develop and increase understanding of mass timber products both from a strength and serviceability perspective. For cross-laminated timber (CLT) there is a significant lack of research on the creep characteristics also known as long-term deflection behavior. Creep is particularly important for products such as CLT that are used for floors with longer spans. Full-scale creep testing was conducted using 5-ply CLT panels over the course of 6 months in a controlled environment under dry service condition. Testing resulted in average final deflections 1.73 times …

University Of Tennessee Outdoor Cultural And Recreational Center, Meredith King

Chancellor’s Honors Program Projects

No abstract provided.

Development Of A First-Generation Prototype Laboratory System For Rail Neutral Temperature Measurements, Ellie Yi-Hsien Chao

Theses and Dissertations

Modern railway tracks worldwide standardize the use of Continuous Welded Rail (CWR) due to its ability to prevent disadvantages associated with rail joints in a track. CWR is laid when the rail is free of thermal stresses, also known as Rail Neutral Temperature (RNT). RNT is controlled in the CWR installation procedure; however, over time, the temperatures deviate from the RNT. The deviation causes significant thermal stresses introduced in the longitudinal direction of the rail, leading to potential failures such as pull-apart and buckling, causing track integrity and safety of train operation. The most significant potential failure is track buckling …

Dynamic Response Of Highway Bridge Superstructures Subjected To Wave Action: Experimental Analysis And Numerical Modeling, Alaa Waleed Hameed

Dissertations and Theses

Bridges are critical lifeline components of the infrastructure network, enabling economies to function under normal conditions and disaster response and recovery missions to take place after extreme events. Therefore, ensuring satisfactory performance increases community resilience and minimizes both human and economic losses. Coastal bridges, which are the focus of this PhD dissertation, are vulnerable to coastal storms. High failure rates of these bridges during two major hurricane events in the mid-2000s have spurred research activities to better understand the wave-induced forces of coastal bridges.

This PhD research represents a continuation effort to build, implement, and introduce new fundamental concepts and …

Structural Design Of Pool House In The City Of Columbia, Nathan F. Gates

Senior Theses

This report presents a structural design for a one-story pool house in the City of Columbia. The most important part of the project was determining critical horizontal and vertical loads, and designing each member in accordance to those governing loads. The loads we analyzed were dynamic, dead, live and seismic. By means of the LRFD method, the greatest possible load combination was calculated, combining the previously mentioned loads. These load combinations were different for each analysis, as the loading pressures will change depending on what structural system is being analyzed. This comprises the large part of the report and of …

Lateral-Torsional Instability And Biaxial Flexure Of Continuous Gfrp Beams Including Warping And Shear Deformations, Waverly G. Hampton

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents an experimental and theoretical study of the lateral-torsional instability and biaxial flexure of Glass Fiber Reinforced Polymer (GFRP) beams including warping and shear deformation effects. The theoretical analysis is based on three simultaneous differential equations of equilibrium with new terms added to account for shear deformation effects. To solve these equations, algorithms based upon a central finite-difference approach are then developed. The experimental study is conducted on a series of single- and multi-span beams subjected to concentrated loads. The predicted beam behavior agreed well with that observed experimentally. The investigation revealed that the ASCE-LRFD Prestandard for pultruded …

Energy Dissipating Connector For Precast Shear Walls In High-Seismic Areas, Mohammed Aljuboori

Theses and Dissertations

ABSTRACT

ENERGY DISSIPATING CONNECTOR FOR PRECAST SHEAR WALLS IN HIGH-SEISMIC AREAS

By

Mohammed Aljuboori

The University of Wisconsin – Milwaukee, 2019

Under the Supervision of Dr. Habib Tabatabai

Precast concrete systems are widely used in a variety of structures such as parking garages, residential units, shopping centers, and transportation stations. In some cases, precast structures are preferred over conventional cast-in-place (CIP) concrete conventional structures because of ease of construction, rapid implementation, and lower levels of energy consumption. One area where precast systems have traditionally been at a disadvantage is high seismic applications. In seismic regions, precast concrete structures must have …

Effect Of Column Axial Load On Skewed Smf Rbs Connection Demands, Clovis Desrochers

Graduate Theses and Dissertations

Steel buildings in high seismic areas often require special structural systems to transfer large lateral forces induced by earthquake accelerations. The selection of an appropriate seismic steel system (braced frame, moment frame, shear wall, etc.) is often influenced by architectural considerations. Moment frame configurations offer the most architectural flexibility, but are limited by code prequalification requirements that limit the use of non-orthogonal (skewed) beam-column connection geometries. A recent study has investigated laterally skewed moment frame connections, indicating that skew increases the potential for column twist and column flange yielding; however, it is unclear how realistic column axial loads will affect …

Weighing The Financial And Sustainable Benefits Of High Performance Structures In Seismically Active Regions, Alia Talina Barajas

Master's Theses

This thesis investigated the potential advantages and disadvantages of high performance structures by comparing the financial and environmental impacts of a performance based four-story office building to one designed to meet minimum code-level requirements.

To generate a comparison, the lateral system of a four-story structure utilizing buckling restrained braced frames was designed to meet code-level requirements per the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures (ASCE 7-05) and again to meet the immediate occupancy criteria defined by ASCE 41-06 Seismic Rehabilitation of Existing Buildings. The following was then performed:

• Test the structural performance of …

Performance-Based Engineering Framework For Earthquake And Fire Following Earthquake, Aerik Carlton

Dissertations, Master's Theses and Master's Reports - Open

The objective for this thesis is to outline a Performance-Based Engineering (PBE) framework to address the multiple hazards of Earthquake (EQ) and subsequent Fire Following Earthquake (FFE). Currently, fire codes for the United States are largely empirical and prescriptive in nature. The reliance on prescriptive requirements makes quantifying sustained damage due to fire difficult. Additionally, the empirical standards have resulted from individual member or individual assembly furnace testing, which have been shown to differ greatly from full structural system behavior. The very nature of fire behavior (ignition, growth, suppression, and spread) is fundamentally difficult to quantify due to the inherent …

Computational Hurricane Hazard Analysis A Performance Based Engineering View, Christopher Michael Vanek

Electronic Theses and Dissertations

Widespread structural damage to critical facilities such as levees, buildings, dams and bridges during hurricanes has exemplified the need to consider multiple hazards associated with hurricanes as well as the potential for unacceptable levels of performance even if failure is not observed. These inadequate standards warrant the use of more accurate methods to describe the anticipated structural response, and damage for extreme events often termed performance based engineering (PBE). Therefore PBE was extended into the field of hurricane engineering in this study. Application of performance-based principles involves collection of the numerous hazards data from sources such as historical records, laboratory …

Finite Element Model Optimization Of The Falconsat-5 Structural Engineering Model, Cole C. Doupe

Theses and Dissertations

Space launch vehicles produce tremendously harsh environments for their payloads. One of the worst contributors to this harsh environment is vibration. Launch vehicle contractors require accurate dynamic models in order to perform coupled loads analyses with each payload to mitigate risks. Accurate predictions of the dynamic response of the payload are not achieved easily. The Finite Element (FE) method has proven to be the best approach in creating accurate dynamic models of complex structures. To improve the agreement between an FE model and the structure it represents, a common practice is to `tune' or adjust parameters of the FE model …

The Application Of Object-Oriented Techniques To Preliminary Design Problems, Patrick S. Mackessy

Theses: Doctorates and Masters

Preliminary structural design is an early stage in building design during which the engineer formulates and assesses a number of different structural schemes. It is conceptual in nature and involves decision making, which relies on heuristics. Whilst preliminary structural design has not been well supported by PC software, recent research has indicated the potential for knowledge-based, object-oriented systems to assist in the area. This thesis explores the issues that arise when object-oriented techniques arc used to develop knowledge-based software. lt reviews certain basic principles of structural design, methods of representing structural design knowledge and earlier approaches to the design of …

The Application Of Sequential Convex Programming To Large-Scale Structural Optimization Problems, Todd A. Sriver

Theses and Dissertations

Structural design problems are often modeled using finite element methods. Such models are often characterized by constraint functions that are not explicitly defined in terms of the design variables. These functions are typically evaluated through numerical finite element analysis (FEA). Optimizing large-scale structural design models requires computationally expensive FEAs to obtain function and gradient values. An optimization approach which uses the SCP sequential convex programming algorithm of Zillober, integrated as the optimizer in the Automated Structural Optimization System (ASTROS), is tested. The traditional approach forms an explicitly defined approximate subproblem at each design iteration that is solved using the method …

Stability Of Steel Structures, Abbas K. Hosseini

Retrospective Theses and Dissertations

In the design of an elastic structure, a major consideration is the overall stability of the system under axial load or a combination of an axial load and bending moment. In first-order analysis the effects of axial forces on the stiffness formulation and their influence on deformations of the members are usually neglected. If the axial forces are sufficiently large, a better indication of the distribution of the forces and moments in the structure is obtained by using a second-order analysis. In this type of analysis the moment equilibrium equations are based on the deformed shape of the structure. The …