Engineering Commons^™

Advancements And Challenges In Additively Manufactured Functionally Graded Materials: A Comprehensive Review, Suhas Alkunte, Ismail Fidan, Vivekanand Naikwadi, Shamil Gudavasov, Mohammad Alshaikh Ali, Mushfig Mahmudov, Seymur Hasanov, Muralimohan Cheepu

Engineering Technology Faculty Publications

This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper explores the applications of FGMs in diverse fields, including structural engineering, automotive, biomedical engineering, soft robotics, electronics, 4D printing, and metamaterials. Critical issues and challenges associated with FGMs are meticulously analyzed, addressing concerns related to production and performance. Moreover, this paper forecasts future trends in FGM development, highlighting potential impacts on diverse industries. The concluding section summarizes …

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.

Cive 440: Reinforced Concrete Design I: Faculty-Led Inquiry Into Reflective And Scholarly Teaching (First) Course Portfolio, Chungwook Sim

UNL Faculty Course Portfolios

This Faculty-led Inquiry into Reflective and Scholarly Teaching (FIRST) Course Portfolio documents the instructor’s teaching practices and student learning for Reinforced Concrete Design I (CIVE 440) course. The contents of this course portfolio captures the CIVE 440 course that was taught on the Lincoln campus during the semester of Fall 2022. CIVE 440 is a structural engineering design elective offered every year in the Department of Civil and Environmental Engineering on both Lincoln and Omaha campus at University of Nebraska-Lincoln (UNL). The course objective is to help students to be able to use theory and experience to proportion and detail …

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 …

Composite Materials And Structures Certificate, Advanced Structures & Composites Center, University Of Maine

General University of Maine Publications

The Certificate requires completion of 12 credits (4 courses) through a combination of 400- and graduate-level courses as described in the course sequence section below. A maximum of one course (or 3 credits) at 400 or 500 level may be transferred from outside of UMaine to the program for credit.

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 …

Strengthening Of Continuous-Span Composite Bridges Using Post-Tensioning And Superimposed Trusses , Hisham Ahmed El-Arabaty

Hisham Ahmed

The need for upgrading understrength bridges in the United States has been well documented in the literature. In this thesis, two methods of strengthening are presented: post-tensioning of the positive moment regions of the bridge stringers and the addition of superimposed trusses at the piers. The use of these two systems is an efficient method of reducing flexural overstresses in undercapacity bridges. The objective of the research described in this thesis was to develop a design methodology to assist bridge engineers with designing a strengthening system to obtain the desired stress reductions. In addition, one such strengthening system was designed …

Thermal Bridging In Concrete Sandwich Walls, Taylor J. Sorensen, Robert J. Thomas, Sattar Dorafshan, Marc Maguire

Faculty Publications

Energy efficiency requires continuity of the insulation system in structural and architectural details.

Coastal Bridges Subjected To Waves: Analysis And Quantification Of Forces, Alaa Waleed Hameed, Thomas Schumacher

Student Research Symposium

Coastal bridges can be exposed to significant wave forces during hurricane events. This research is studying the parameters that govern the structural response through data analysis of a large experimental data set. This data set was generated by testing a heavily-instrumented 1:5-scale bridge superstructure model, which was modeled after the I-10 Bridge over the Escambia Bay, under various wave conditions and water levels in a large wave flume. A unique aspect of the model is that the flexibility of the substructure can be adjusted to represent different types of bridge support systems. This poster discusses the first part of the …

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 …

Thermal And Fatigue Testing Of Fiber Reinforced Polymer Tie Connectors Used In Concrete Sandwich Walls , Anthony William Post

Anthony Williams

The purpose of this research program was to determine the strength, strain, fatigue, temperature, and other corresponding behavioral characteristics of concrete sandwich wall panels containing the new Delta TieRTM fiber reinforced polymer (FRP) tie connector produced by Dayton/Richmond, a brand of Dayton Superior. The scope of this program included a matrix of three full-scale 40'-0'' wall panels subjected to a 100°F temperature differential, and a matrix of six elemental specimens, three with the ties oriented in the strong direction (parallel tie orientation) and three with the ties oriented in the weak direction (perpendicular tie orientation), subjected to cyclic load tests …

Selected Research And Development Projects, Advanced Structures & Composites Center, University Of Maine

General University of Maine Publications

Promotional flyer with summaries of a selection of research and development projects including VolturnUS 1:8, DeepCLiDAR, Composite Arch Bridge System, MAKO, Secure Hybrid Composite Shipping Container, Modular Ballistic Protection System, and NASA HAID.

Daylighting And Thermo-Electrical Performance Of An Autonomous Suspended Particle Device Evacuated Glazing, Aritra Ghosh

Doctoral

Suspended particle device (SPD) glazing is an AC powered switchable glazing. PV powered SPD evacuated (vacuum) glazing was proposed with the potential of reducing the heating demand, cooling demand and artificial lighting demand of a building. To achieve an autonomous SPD vacuum glazing, semi empirical simulation and outdoor characterisation was explored in this thesis. Transmission of SPD glazing (area 0.058 m2) varied from 5% when opaque to 55% when transparent in the presence of 110 V, 0.07 W AC supply was characterised in outdoor test cell in Dublin. The SPD glazing has variable spectral transmission in the presence of variable …

Examples Of Material Property Testing, Advanced Structures & Composites Center, University Of Maine

General University of Maine Publications

No abstract provided.

Investigation Of Waviness In Wind Turbine Blades: Structural Health Monitoring, Sunil Kishore Chakrapani, Vinay Dayal, Daniel J. Barnard

Sunil Kishore Chakrapani

Waviness in composite wind turbine blades was detected and characterized with the help of air coupled ultrasonics. Based on the aspect ratio, the detected marcels are either accepted or rejected. A passive structural health monitoring approach has been presented here to monitor the accepted marcels above a threshold. The fatigue life of specimen is most affected in the presence of a marcel. Hence this study focused on the damage evaluation after fatigue testing. Wavy laminate was subjected to fatigue load to investigate the fracture mechanisms near the marcel. Different types of defects were identified from this study and were used …

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 …

Using Model Building In Structural Engineering To Enhance Understanding Of Construction Principles And Methods, Niall Holmes, Henry Mullen

Articles

This paper presents a new model building exercise in a second year module in the Department of Civil & Structural Engineering in the Dublin Institute of Technology (DIT). The activity aimed to improve students’ understanding of structural engineering, construction principles and methods. It allowed students to practically apply lecture material and construct a scaled model giving them an opportunity to study and visualise a real structure and generate their own ideas on how it should be assembled within a constructivist active learning environment. As a result, lectures were found to be more interactive and students more engaged in the discussions …

Simulating Gpr For Diagnosis Of Civil Infrastructure, Laura Carey, Kimberly Belli, Carey M. Rappaport, Sara J. Wadia-Fascetti

Sara J. Wadia-Fascetti

At the present, a large proportion of our nation's bridges and roadways are falling into disrepair. About 27.5% of U.S. bridges are structurally deficient or functionally obsolete (ASCE, 2001, 2003). Nondestructive testing methods, such as GPR, are becoming more and more important in diagnosing the condition of such concrete structures. GPR is a high-resolution electromagnetic technique used to investigate the immediate subsurface of the earth, building materials, roads, and bridges. This poster shows my work in GPR modeling during a summer undergraduate experience through CenSSIS. A specialized MATLAB toolbox designed by Kim Belli created all data presented here. The use …

Simulating Gpr For Diagnosis Of Civil Infrastructure, Laura Carey, Kimberly Belli, Carey M. Rappaport, Sara J. Wadia-Fascetti

Kimberly Belli

At the present, a large proportion of our nation's bridges and roadways are falling into disrepair. About 27.5% of U.S. bridges are structurally deficient or functionally obsolete (ASCE, 2001, 2003). Nondestructive testing methods, such as GPR, are becoming more and more important in diagnosing the condition of such concrete structures. GPR is a high-resolution electromagnetic technique used to investigate the immediate subsurface of the earth, building materials, roads, and bridges. This poster shows my work in GPR modeling during a summer undergraduate experience through CenSSIS. A specialized MATLAB toolbox designed by Kim Belli created all data presented here. The use …

Simulating Gpr For Diagnosis Of Civil Infrastructure, Laura Carey, Kimberly Belli, Carey M. Rappaport, Sara J. Wadia-Fascetti

Carey Rappaport

At the present, a large proportion of our nation's bridges and roadways are falling into disrepair. About 27.5% of U.S. bridges are structurally deficient or functionally obsolete (ASCE, 2001, 2003). Nondestructive testing methods, such as GPR, are becoming more and more important in diagnosing the condition of such concrete structures. GPR is a high-resolution electromagnetic technique used to investigate the immediate subsurface of the earth, building materials, roads, and bridges. This poster shows my work in GPR modeling during a summer undergraduate experience through CenSSIS. A specialized MATLAB toolbox designed by Kim Belli created all data presented here. The use …

Material Characterization And Computational Simulation Of Steel Foam For Use In Structural Applications, Brooks H. Smith

Masters Theses 1911 - February 2014

Cellular metals made from aluminum, titanium, or other metals are becoming increasingly popular for use in structural components of automobiles, aircraft, and orthopaedic implants. Civil engineering applications remain largely absent, primarily due to poor understanding of the material and its structural properties. However, the material features a high stiffness to weight ratio, excellent energy dissipation, and low thermal conductivity, suggesting that it could become a highly valuable new material in structural engineering. Previous attempts to characterize the mechanical properties of steel foam have focused almost exclusively upon uniaxial compression tests, both in experimental research and in computational simulations. Further, computational …

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 …

Undergraduate Summer Research In Structural Engineering, Norbert J. Delatte

Civil and Environmental Engineering Faculty Publications

For the last seven years, a summer Research Experiences for Undergraduates site in structural engineering, funded by the National Science Foundation, has operated at the University of Alabama at Birmingham. During this time, 33 students from 22 colleges and universities have participated in the site. Participants are recruited nationally and have come from as far away as California and Puerto Rico. The program is intended to provide students interested in graduate studies with an introduction to research methods, and to provide students who will not continue their studies past a bachelor of science in civil engineering with a better understanding …