Engineering Commons^™

Simulation Of Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries, Katie Sue Bruggeman

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Residual stresses developed during additive manufacturing (AM) can influence the mechanical performance of structural components in their intended applications. In this study, thermomechanical residual stress simulations of the laser powder bed fusion (LPBF) process are conducted for both simplified (plate and cube-shaped) geometries as well as five complex lattice geometries fabricated with Inconel 718. These simulations are conducted with the commercial software package Simufact Additive©, which uses a non-linear finite element analysis and layer-by-layer averaging approach in determining residual stresses. To verify the efficacy of the Simufact Additive© simulations, numerical results for the plate and cube-shape geometries are analyzed for …

Hypersonic Conceptual Design Tool Comparison, James G. Wnek

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The many iterations needed to explore a design space in the conceptual design process preclude the use of time-consuming RANS CFD for all but a few flight conditions. This research focuses on identifying the level of fidelity needed to adequately predict the aerothermodynamic characteristics of hypersonic vehicles. Three tools with differing levels of fidelity – CBAERO, Cart3D, and Kestrel – were used to analyze the Generic Hypersonic Vehicle (GHV) at the design condition of Mach 5.85 and an off-design condition of Mach 4.5. The results are representative of the different design tools but are not definitive due to the mesh …

Vibration Bending Fatigue Analysis Of Additively Repaired Ti-6al-4v Airfoil Blades, Lucas Jordan Smith

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Repairing airfoil blades is necessary to extend the life of turbine engines. Directed energy deposition (DED) additive manufacturing (AM) provides the ability to add material at a specific location on an existing component. In this work, AM repairs on Ti-6Al-4V airfoil blades were analyzed to determine what effect the repair will have on the blade performance in high cycle vibration fatigue testing. Targeted sections were cut out of airfoil blades near high stress locations and repaired using DED. To understand the defects that arose with this type of repair, computed tomography imaging was used to quantify the defects from the …

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]

Spray Deposition Of Sustainable Plant Based Graphene In Thermosetting Carbon Fiber Laminates For Mechanical, Thermal, And Electrical Properties, Daniel W. Mulqueen, Siavash Sattar, Thienan Le, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

Graphene has generated substantial interest as a filler due to its exceptional strength, flexibility, and conductivity but faces obstacles in supply and implementation. A renewable, plant-based graphene nanoparticle (pGNP) presents a more accessible filler with the same properties as mineral graphenes. In this study, we examine the effects of pGNP, which was sprayed on a carbon fiber/epoxy prepreg at loadings from 1.1 to 4.2 g/m². The study considered the mechanical, thermal, and electrical properties of pGNP-composite. An even particle dispersion was achieved using a spray application of pGNP in a water/alcohol suspension with the addition of surfactants and …

Human Ergonomic Simulation To Support The Design Of An Exoskeleton For Lashing/De-Lashing Operations Of Containers Cargo, Francesco Longo, Antonio Padovano, Vittorio Solina, Virginia D' Augusta, Stefan Venzl, Roberto Calbi, Michele Bartuni, Ornella Anastasi, Rafael Diaz

VMASC Publications

Lashing and de-lashing operations of containers cargo on board containerships are considered as quite strenuous activities in which operators are required to work continuously over a 6 or 8 hours shift with very limited break. This is mostly because containerships need to leave the port as soon as possible and containers loading and unloading operations must be executed with very high productivity (stay moored in a port is a totally unproductive time for a ship and a loss-making business for a shipping company). Operators performing lashing and de-lashing operations are subjected to intense ergonomic stress and uncomfortable working postures. To …

A Simulation-Based Disaster Management Framework To Analyze Housing Recovery: The Case Of Hampton Roads, Usa, Rafael Diaz, Joshua Behr, Beatriz Acero, Bridget D. Giles, Juita-Elena Wie Yusuf

VMASC Publications

In the aftermath of a catastrophic weather event, housing recovery and reconstruction activities are highly complex. Coordinating housing recovery activities is generally challenging because complex supply chains converge simultaneously in a highly uncertain environment. In this environment, anticipating and quantifying the extent of potential damage and determining the actions that must be taken to rebuild the housing stock may assist regions in allocating resources for reconstruction. This paper presents the development of a comprehensive disaster management framework to assist decision-makers in predicting the impact of projected natural disasters on housing. This framework uses a simulation-based approach to quantify likely regional …

Simulation-Based Optimization: Implications Of Complex Adaptive Systems And Deep Uncertainty, Andreas Tolk

VMASC Publications

Within the modeling and simulation community, simulation-based optimization has often been successfully used to improve productivity and business processes. However, the increased importance of using simulation to better understand complex adaptive systems and address operations research questions characterized by deep uncertainty, such as the need for policy support within socio-technical systems, leads to the necessity to revisit the way simulation can be applied in this new area. Similar observations can be made for complex adaptive systems that constantly change their behavior, which is reflected in a continually changing solution space. Deep uncertainty describes problems with inadequate or incomplete information about …

Combining Green Metrics And Digital Twins For Sustainability Planning And Governance Of Smart Buildings And Cities, Casey R. Corrado, Suzanne M. Delong, Emily G. Holt, Edward Y. Hua, Andreas Tolk

VMASC Publications

Creating a more sustainable world will require a coordinated effort to address the rise of social, economic, and environmental concerns resulting from the continuous growth of cities. Supporting planners with tools to address them is pivotal, and sustainability is one of the main objectives. Modeling and simulation augmenting digital twins can play an important role to implement these tools. Although various green best practices have been utilized over time and there are related attempts at measuring green success, works in the published literature tend to focus on addressing a single problem (e.g., energy efficiency), and a comprehensive approach that takes …

Mechanism For Selective Binding Of Aromatic Compounds On Oxygen-Rich Graphene Nanosheets Based On Molecule Size/Polarity Matching, Heyun Fu, Bingyu Wang, Dongqiang Zhu, Zhicheng Zhou, Shidong Bao, Xiaolei Qu, Yong Guo, Lan Ling, Shourong Zheng, Pu Duan, Jingdong Mao, Klaus Schmidt-Rohr, Shu Tao, Pedro J.J. Alvarez

Chemistry & Biochemistry Faculty Publications

Selective binding of organic compounds is the cornerstone of many important industrial and pharmaceutical applications. Here, we achieved highly selective binding of aromatic compounds in aqueous solution and gas phase by oxygen-enriched graphene oxide (GO) nanosheets via a previously unknown mechanism based on size matching and polarity matching. Oxygen-containing functional groups (predominately epoxies and hydroxyls) on the nongraphitized aliphatic carbons of the basal plane of GO formed highly polar regions that encompass graphitic regions slightly larger than the benzene ring. This facilitated size match–based interactions between small apolar compounds and the isolated aromatic region of GO, resulting in high binding …

A Local Mode Study Of Ring Puckering Effects In The Infrared Spectra Of Cyclopentane, Edwin L. Sibert Iii, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

We report and interpret recently recorded high-resolution infrared spectra for the fundamentals of the CH₂ scissors and CH stretches of gas phase cyclopentane at −26.1 and −50 ^○C, respectively. We extend previous theoretical studies of this molecule, which is known to undergo barrierless pseudorotation due to ring puckering, by constructing local mode Hamiltonians of the stretching and scissor vibrations for which the frequencies, couplings, and linear dipoles are calculated as functions of the pseudorotation angle using B3LYP/6-311++(d,p) and MP2/cc-pVTZ levels of theory. Symmetrization (D_5h) of the vibrational basis sets leads to simple vibration/pseudorotation Hamiltonians whose solutions …

Integrating Deep Learning And Hydrodynamic Modeling To Improve The Great Lakes Forecast, Pengfei Xue, Aditya Wagh, Gangfeng Ma, Yilin Wang, Yongchao Yang, Tao Liu, Chenfu Huang

Civil & Environmental Engineering Faculty Publications

The Laurentian Great Lakes, one of the world’s largest surface freshwater systems, pose a modeling challenge in seasonal forecast and climate projection. While physics-based hydrodynamic modeling is a fundamental approach, improving the forecast accuracy remains critical. In recent years, machine learning (ML) has quickly emerged in geoscience applications, but its application to the Great Lakes hydrodynamic prediction is still in its early stages. This work is the first one to explore a deep learning approach to predicting spatiotemporal distributions of the lake surface temperature (LST) in the Great Lakes. Our study shows that the Long Short-Term Memory (LSTM) neural network, …

Recent Advancements In Electrochemical Conversion Of Carbon Dioxide, Nandan Nag, Amit Kumar, Sumit Sharma, Sandeep Kumar, Amit K. Thakur

Civil & Environmental Engineering Faculty Publications

Electrochemical reduction of carbon dioxide into eco-friendly and clean products is a promising approach to eradicate pollution. Although carbon dioxide emission is inhibited by the advent of renewable sources of energy, it is present in the atmosphere and needs to be cleaned. The reduction of carbon dioxide from atmospheric gases can be accomplished by its adsorption and subsequent transportation to electrolytic chambers, where it is reduced to hydrocarbons, organic acids or carbonates. This review focuses on developing a three compartment electrochemical cell to reduce carbon dioxide used as a catholyte. Various factors affecting the electrochemical reduction of carbon dioxide and …

Lateral-Torsional Instability And Biaxial Bending Of Imperfect Frp I-Beams, Jodi Knorowski, Stella B. Bondi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents the outcome of a theoretical and experimental study of the behavior of Fiber Reinforced Polymer (FRP) I-beams exposed to lateral-torsional instability or when subjected to biaxial bending. Laboratory experiments involved the application of vertical and horizontal static loads to a 4 x 4 x ¼ in. I-beam with various lengths and the resulting deflections were recorded. Governing biaxial flexure and torsion differential equations were modified to account for the presence of initial imperfections and subsequently solved using a central finite-difference scheme. The theoretical predictions of the beam behavior were found to be in good agreement with what …

Method For Reducing Warping Stresses In Torsionally Loaded I-Section Members Using Cfrp Plates, Mamadou Konate, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents a method for reducing warping normal stresses in torsionally loaded I-section members by utilizing carbon fiber-reinforced polymer (CFRP) plates. The CFRP plates are bonded to the outer surfaces of the flanges with a view to reducing warping normal stresses. The maximum warping normal stress in the flanges of a steel I-shaped member without the CFRP plates is compared to those obtained with the CFRP plates having various thicknesses. It has been found that the use of CFRP plates bonded to both flanges of the I-section result in a substantial reduction of the warping stresses. For the study …

Core Point Pixel-Level Localization By Fingerprint Features In Spatial Domain, Xueyi Ye, Yuzhong Shen, Maosheng Zeng, Yirui Liu, Huahua Chen, Zhijing Zhao

Computational Modeling & Simulation Engineering Faculty Publications

Singular point detection is a primary step in fingerprint recognition, especially for fingerprint alignment and classification. But in present there are still some problems and challenges such as more false-positive singular points or inaccurate reference point localization. This paper proposes an accurate core point localization method based on spatial domain features of fingerprint images from a completely different viewpoint to improve the fingerprint core point displacement problem of singular point detection. The method first defines new fingerprint features, called furcation and confluence, to represent specific ridge/valley distribution in a core point area, and uses them to extract the innermost Curve …

Graphical Revamping Of A Crude Distillation Unit Under Two Variable Operational Scenarios - Naphtha Stabilizer And Reformer Operated, Amany G. Abo-Mousa, Dina A. Kamel, Hany A. Elazab, Mamdouh A. Gadalla, Mai K. Fouad

Chemical and Biochemical Engineering Faculty Research & Creative Works

Energy costs represent significant parts of the total operating costs of crude refining industries. Energy integration is a typical solution to reduce heating and cooling utilities in crude refining plants through maximizing the target temperature of crude oil streams before entering the furnace. Over the past few decades, a significant progress has been made in energy integration methods including Pinch technology and mathematical programming approaches. Example of these is a graphical technique which plots Thot versus Tcold for energy analysis and revamping studies. The current research employs the Thot - Tcold diagrams in an algorithm to retrofit an existing crude …

Effect Of Açai Berry Extract Application On The Bond Strength To The Bleached Enamel Using An Experimental Etch-And-Rinse Adhesive, Lamiaa M. Moharam, Haidy N. Salem, Shahinaz N. Hassan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: To evaluate the bleached enamel shear bond strength (SBS) after antioxidants application using an experimental adhesive. Material and Methods: Sixty sound human molars had their roots removed then cut into buccal and lingual halves and mounted in acrylic blocks. Enamel bleaching was done using an in-office chemical bleaching agent. Specimens were arbitrarily allocated into 12 groups (n=10) regarding the three experimental levels of the study: two antioxidant agents [10% açai berry extract, 10% sodium ascorbate prepared gels (applied for 15-min) and the control group (no antioxidant application)], two adhesive materials [commercial etch-and-rinse (ER) adhesive and an experimental ER adhesive] …

Critical Thinking To Creative Problem-Solving In Engineering And Management, Baher Amouzgar

Walden Dissertations and Doctoral Studies

Organizations advance and grow by solving problems one at a time, and management graduates should possess critical thinking and problem-solving capacities to be effective business managers and creative engineers. The problem was that critical thinking and creative problem solving are operationally ill-defined in engineering and management education. The purpose of this grounded theory study was to discover how, if at all, the engineering and management scholar-practitioner community in British Columbia, Canada, perceives the concepts of critical thinking and creative problem-solving. A three-prong critical thinking conceptual framework was used as template for defining and relating the two key concepts of the …

New Development Of Neutrosophic Probability, Neutrosophic Statistics, Neutrosophic Algebraic Structures, And Neutrosophic Plithogenic Optimizations, Florentin Smarandache, Yanhui Guo

Branch Mathematics and Statistics Faculty and Staff Publications

This collective book presents state-of-the-art papers on new topics related to neutrosophic theories, such as neutrosophic algebraic structures, neutrosophic triplet algebraic structures, neutrosophic extended triplet algebraic structures, neutrosophic algebraic hyperstructures, neutrosophic triplet algebraic hyperstructures, neutrosophic n-ary algebraic structures, neutrosophic n-ary algebraic hyperstructures, refined neutrosophic algebraic structures, refined neutrosophic algebraic hyperstructures, quadruple neutrosophic algebraic structures, refined quadruple neutrosophic algebraic structures, neutrosophic image processing, neutrosophic image classification, neutrosophic computer vision, neutrosophic machine learning, neutrosophic artificial intelligence, neutrosophic data analytics, neutrosophic deep learning, and neutrosophic symmetry, as well as their applications in the real world.

Soft Set Product Extended To Hypersoft Set And Indetermsoft Set Product Extended To Indetermhypersoft Set, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper we define the Soft Set Product as a product of many soft sets and afterwards we extend it to the HyperSoft Set. Similarly, the IndetermSoft Product is extended to the IndetermHyperSoft Set. We also present several applications of the Soft Set Product to Fuzzy (and fuzzy-extensions) Soft Set Product and to IndetermSoft Set and IndetermHyperSoft Set.

Collected Papers (On Neutrosophic Theory And Applications), Volume Vii, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This seventh volume of Collected Papers includes 70 papers comprising 974 pages on (theoretic and applied) neutrosophics, written between 2013-2021 by the author alone or in collaboration with 122 co-authors from 22 countries.

Collected Papers (On Neutrosophic Theory And Applications), Volume Viii, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This eighth volume of Collected Papers includes 75 papers comprising 973 pages on (theoretic and applied) neutrosophics, written between 2010-2022 by the author alone or in collaboration with 102 co-authors from 24 countries.

Collected Papers (On Neutrosophic Theory And Its Applications In Algebra), Volume Ix, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This ninth volume of Collected Papers includes 87 papers comprising 982 pages on Neutrosophic Theory and its applications in Algebra, written between 2014-2022 by the author alone or in collaboration with 81 co-authors from 19 countries.

Neutrosophic Algebraic Structures And Their Applications, Florentin Smarandache, Memet Sahin, Derya Bakbak, Abdullah Kargın

Branch Mathematics and Statistics Faculty and Staff Publications

Neutrosophic Logic is a general framework for unification of many existing logics, such as fuzzy logic (especially intuitionistic fuzzy logic), paraconsistent logic, intuitionistic logic, etc.

In 2019 Smarandache generalized the classical Algebraic Structures to NeutroAlgebraic Structures (or NeutroAlgebras) {whose operations and axioms are partially true, partially indeterminate, and partially false} as extensions of Partial Algebra, and to AntiAlgebraic Structures (or AntiAlgebras) {whose operations and axioms are totally false}, and he continued to develop them and extend a Structure in any field to the NeutroStructure and AntiStructure.

The NeutroAlgebras & AntiAlgebras are a new field of research, which is inspired from …

Collected Papers (On Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics), Volume Xi, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This eleventh volume of Collected Papers includes 90 papers comprising 988 pages on Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics, written between 2001-2022 by the author alone or in collaboration with 84 co-authors from 19 countries.

Collected Papers (On Neutrosophic Theory And Applications), Volume Vi, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This sixth volume of Collected Papers includes 74 papers comprising 974 pages on (theoretic and applied) neutrosophics, written between 2015-2021 by the author alone or in collaboration with 121 co-authors from 19 countries.

Collected Papers (On Neutrosophics, Plithogenics, Hypersoft Set, Hypergraphs, And Other Topics), Volume X, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This tenth volume of Collected Papers includes 86 papers in English and Spanish languages comprising 972 pages, written between 2014-2022 by the author alone or in collaboration with 105 co-authors from 26 countries.

Collected Papers (Neutrosophics And Other Topics), Volume Xiv, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This fourteenth volume of Collected Papers is an eclectic tome of 87 papers in Neutrosophics and other fields, such as mathematics, fuzzy sets, intuitionistic fuzzy sets, picture fuzzy sets, information fusion, robotics, statistics, or extenics, comprising 936 pages, published between 2008-2022 in different scientific journals or currently in press, by the author alone or in collaboration with 99 co-authors from 26 countries.

On Neutrosophic Αψ -Supra Open Sets, Mani Parimala, Muthusamy Karthika, Harish Garg, Saeid Jafari, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

Neutrosophic topological space is an extension of fuzzy topology. Neutrosophic topological space addresses each element’s membership, indeterminacy and non-membership grades. Dropping an axiom in the neutrosophic topological space produces a new topological space called neutrosophic supra topological space. Elements in this neutrosophic supra topology are neutrosophic sets. We established the neutrosophic αψ-supra open set in neutrosophic supra topological spaces in this paper. Also, we investigate the properties of the newly defined set. Neutrosophic αψ -supra continuity is introduced and studied subsequently.