Mechanical Engineering Commons^™

Atmospheric Plasma Spraying To Fabricate Metal-Supported Solid Oxide Fuel Cells With Open-Channel Porous Metal Support, Jie Lin, Haixia Li, Wanhua Wang, Peng Qiu, Greg Tao, Kevin Huang, Fanglin Chen

Faculty Publications

Metal-supported solid oxide fuel cells (MS-SOFCs) have been fabricated by applying phase-inversion tape-casting and atmospheric plasma spraying (APS). The effect of the binder amount of the phase-inversion slurries on the microstructure development of the 430L stainless steel metal support was investigated. The pore structures, the viscosity of the slurry, porosity and permeability of the as-prepared metal supports are significantly influenced by the amount of the binder. NiO–scandia-stabilized zirconia (ScSZ) anode, ScSZ electrolyte and La_0.6Sr_0.4Co_0.2Fe0.8O_3−δ (LSCF) cathode layers were consecutively deposited on the metal support with an ideal microstructure by APS process. The effect …

Fundamental Study Of Multiphase Solid/Molten Carbonate Membranes For Co2 Capture And Conversion, Xin Li

Theses and Dissertations

Due to the burning of fossil fuels and human activities, many greenhouse gases such as carbon dioxide are released into the atmosphere, which causes global warming and has a significant negative impact on the human living environment. Therefore, it is imperative to develop carbon capture technologies that can prevent carbon dioxide emission and reduce carbon dioxide concentration in the air. Further, if the captured carbon dioxide can be converted back to fossil fuels, the emission of carbon dioxide is delayed, and more time is gained to develop new and advanced carbon free and clean energy technologies. Motivated by this thought, …

Advancement Of New Solid-Oxide Iron-Air Battery (Soiab) Operated On High-Temperature Oxide-Ion Chemistry, Qiming Tang

Theses and Dissertations

Climate change caused by anthropogenic greenhouse gas (GHG) emissions such as the burning of fossil fuels for power generation and industrial processing is affecting the global climate. To address this critical issue, a transition from fossil energy to renewable energy, especially wind and solar, is necessary. However, to successfully realize this transition, a cost-effective and large-scale stationary electricity storage system is indispensable. In this work, a new type of solid-oxide iron-air battery (SOIAB) operated on high-temperature oxide-ion chemistry is studied for this purpose due to its unique cycling characteristics suitable for large-scale Long Duration Electricity Storage (LDES) applications.

In the …

Characterization Of Nonequilibrium Plasma Discharge In High Water Vapor Concentration, Malik Mohammad Tahiyat

Theses and Dissertations

In recent years, plasma discharge in liquid medium has been a topic of immense interest. Theoretical efforts have been pursued to obtain insight on physicochemical processes being influenced due to trace water vapor either being present as residual or provided at a known concentration. However, studies on discharge at high vapor content are limited. In this study, discharge characteristics of plasma in high water concentration (> 90%) are investigated experimentally for a pressure range of 1 – 15 Torr to maximize vapor loading without condensation. Voltage-current characteristics were obtained over 0- 14 mA of current for each operating pressure; current …

On The Influence Of Afp-Induced Defects On Mechanical Behavior Of Composite Laminates Under Fatigue Loading, Pierre Chevalier

Theses and Dissertations

The objective of the work presented in this thesis is to propose and validate a numerical solution to quantify the influence of Automated Fiber Placement (AFP) induced defects on the mechanical behavior of conventional composite laminates in fatigue. The work presented here will be divided in six sections. At first, a description of the Automated Fiber Placement process and its associated defects is proposed. In association, two tools developed for a rapid analysis and a progressive damage analysis respectively are discussed and used as an introduction to the work conducted in this thesis. In the second section, an extensive literature …

Intermediate Temperature Solid Oxide Cell With A Barrier Layer Free Oxygen Electrode And Phase Inversion Derived Hydrogen Electrode, Yongliang Zhang, Nansheng Xu, Qiming Tang, Kevin Huang

Faculty Publications

High-temperature solid oxide cells (SOCs) have fundamental advantages in efficiency and product rate over their low-temperature counterparts. However, the commercial development of SOCs is hindered by cost and reliability. To solve the issues, lowering the operating temperature of SOCs is deemed the best solution. Here we report on our effort toward intermediate temperature (IT) SOCs by developing a barrier layer free high-performance oxygen electrode and open structured hydrogen electrode. The results show that the new oxygen electrode provides reasonably good oxygen electrocatalytic activity at IT range for oxygen reduction and evolution reactions and the open structured hydrogen electrode provides low …

Fourth-Order Adjoint Sensitivity And Uncertainty Analysis Of An Oecd/Nea Reactor Physics Benchmark: Ii. Computed Response Uncertainties, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

This work quantifies the impact of the most important 4th-order sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) reactor physics benchmark with respect to the benchmark’s 180 group-averaged microscopic total cross sections, on the expected value, variance and skewness of the benchmark’s leakage response. This work shows that, as the standard deviations of the cross sections increase, the contributions of the 4th-order sensitivities to the response’s expected value and variance become significantly larger than the corresponding contributions stemming from the 1st-, 2nd- and 3rd-order sensitivities. Considering a uniform 5% relative standard deviation for all microscopic total cross sections, …

Decellularized Articular Cartilage Microgels As Microcarriers For Expansion Of Mesenchymal Stem Cells, Esmaiel Jabbari, Azadeh Sepahvandi

Faculty Publications

Conventional microcarriers used for expansion of human mesenchymal stem cells (hMSCs) require detachment and separation of the cells from the carrier prior to use in clinical applications for regeneration of articular cartilage, and the carrier can cause undesirable phenotypic changes in the expanded cells. This work describes a novel approach to expand hMSCs on biomimetic carriers based on adult or fetal decellularized bovine articular cartilage that supports tissue regeneration without the need to detach the expanded cells from the carrier. In this approach, the fetal or adult bovine articular cartilage was minced, decellularized, freeze-dried, ground, and sieved to produce articular …

Decellularized Articular Cartilage Microgels As Microcarriers For Expansion Of Mesenchymal Stem Cells, Esmaiel Jabbari, Azadeh Sepahvandi

Faculty Publications

Conventional microcarriers used for expansion of human mesenchymal stem cells (hMSCs) require detachment and separation of the cells from the carrier prior to use in clinical applications for regeneration of articular cartilage, and the carrier can cause undesirable phenotypic changes in the expanded cells. This work describes a novel approach to expand hMSCs on biomimetic carriers based on adult or fetal decellularized bovine articular cartilage that supports tissue regeneration without the need to detach the expanded cells from the carrier. In this approach, the fetal or adult bovine articular cartilage was minced, decellularized, freeze-dried, ground, and sieved to produce articular …

Fourth-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Nonlinear Systems (4th-Casam-N): I. Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the fourth-order comprehensive sensitivity analysis methodology for nonlinear systems (abbreviated as “4th-CASAM-N”) for exactly and efficiently computing the first-, second-, third-, and fourth-order functional derivatives (customarily called “sensitivities”) of physical system responses (i.e., “system performance parameters”) to the system’s (or model) parameters. The qualifier “comprehensive” indicates that the 4th-CASAM-N methodology enables the exact and efficient computation not only of response sensitivities with respect to the customary model parameters (including computational input data, correlations, initial and/or boundary conditions) but also with respect to imprecisely known material boundaries, caused by manufacturing tolerances, of the system under consideration. The 4th-CASAM-N …

Large Scale Dataset Of Real Space Electronic Charge Density Of Cubic Inorganic Materials From Density Functional Theory (Dft) Calculations, Fancy Qian Wang, Kamal Choudhary, Jianjun Hu, Ming Hu

Faculty Publications

Driven by the big data science, material informatics has attracted enormous research interests recently along with many recognized achievements. To acquire knowledge of materials by previous experience, both feature descriptors and databases are essential for training machine learning (ML) models with high accuracy. In this regard, the electronic charge density ρ(r), which in principle determines the properties of materials at their ground state, can be considered as one of the most appropriate descriptors. However, the systematic electronic charge density ρ(r) database of inorganic materials is still in its infancy due to the difficulties in …

Strong Laser Polarization Control Of Coherent Phonon Excitation In Van Der Waals Material Fe3Gete2, Yu Gong, Ming Hu, Nico Harris, Zhonghua Yang, Ti Xie, Alem Teklu, Narayanan Kuthirummal, Jacob Koenemann, Xianghan Xu, Sang-Wook Cheong, Will Mcloud, Cheng Gong

Faculty Publications

Optical manipulation of coherent phonon frequency in two-dimensional (2D) materials could advance the development of ultrafast phononics in atomic-thin platforms. However, conventional approaches for such control are limited to doping, strain, structural or thermal engineering. Here, we report the experimental observation of strong laser-polarization control of coherent phonon frequency through time-resolved pump-probe spectroscopic study of van der Waals (vdW) materials Fe₃GeTe₂. When the polarization of the pumping laser with tilted incidence is swept between in-plane and out-of-plane orientations, the frequencies of excited phonons can be monotonically tuned by as large as 3% (~100 GHz). Our first-principles …

An Artificial Intelligence Approach To Fatigue Crack Length Estimation From Acoustic Emission Waves In Thin Metallic Plates, Joseph Chandler Garrett, Hanfei Mei, Victor Giurgiutiu

Faculty Publications

The acoustic emission (AE) technique has become a well-established method of monitoring structural health over recent years. The sensing and analysis of elastic AE waves, which have involved piezoelectric wafer active sensors (PWAS) and time domain and frequency domain analysis, has proven to be effective in yielding fatigue crack-related information. However, not much research has been performed regarding (i) the correlation between the fatigue crack length and AE signal signatures and (ii) artificial intelligence (AI) methodologies to automate the AE waveform analysis. In this paper, this crack length correlation is investigated along with the development of a novel AE signal …

Surface Acoustic Wave (Saw) Sensors: Physics, Materials, And Applications, Debdyuti Mandal, Sourav Banerjee

Faculty Publications

Surface acoustic waves (SAWs) are the guided waves that propagate along the top surface of a material with wave vectors orthogonal to the normal direction to the surface. Based on these waves, SAW sensors are conceptualized by employing piezoelectric crystals where the guided elastodynamic waves are generated through an electromechanical coupling. Electromechanical coupling in both active and passive modes is achieved by integrating interdigitated electrode transducers (IDT) with the piezoelectric crystals. Innovative meta-designs of the periodic IDTs define the functionality and application of SAW sensors. This review article presents the physics of guided surface acoustic waves and the piezoelectric materials …

Effect Of Defects Part I: Degradation Of Constitutive Coefficients As An Input To The Composite Failure Model With Microvoids And Porosity, Vahid Tavaf, Sourav Banerjee

Faculty Publications

It is always challenging to provide appropriate material properties for a composite progressive failure model. The nonstandard percentage reduction method that is commonly used to degrade the material constants with micro-scale defects generates tremendous uncertainty in failure prediction. The constitutive matrix is composed of multiple material constants. It is not necessary that all constants degrade either equally or linearly due to a certain state of material defects. With this very concern in mind, this article presents a guideline for using a quantified perturbation for each coefficient appropriately. It also presents distribution of effective material properties (EMPs) in unidirectional composite materials …

Rapid Ac Electrokinetic Micromixer With Electrically Conductive Sidewalls, Fang Yang, Wei Zhao, Cuifang Kuang, Guiren Wang

Faculty Publications

We report a quasi T-channel electrokinetics-based micromixer with electrically conductive sidewalls, where the electric field is in the transverse direction of the flow and parallel to the conductivity gradient at the interface between two fluids to be mixed. Mixing results are first compared with another widely studied micromixer configuration, where electrodes are located at the inlet and outlet of the channel with electric field parallel to bulk flow direction but orthogonal to the conductivity gradient at the interface between the two fluids to be mixed. Faster mixing is achieved in the micromixer with conductive sidewalls. Effects of Re numbers, applied …

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): Ii. Illustrative Application, Dan Gabriel Cacuci

Faculty Publications

This work illustrates the application of the n^th-order comprehensive adjoint sensitivity analysis methodology for response-coupled forward/adjoint linear systems (abbreviated as “n^th-CASAM-L”) to a paradigm model that describes the transmission of particles (neutrons and/or photons) through homogenized materials, as encountered in radiation protection and shielding. The first-, second-, and third-order sensitivities of responses that depend on both the forward and adjoint particle fluxes are obtained exactly, in closed-form, underscoring the principles and methodology underlying the n^th-CASAM-L. The results presented in this work underscore the fundamentally important role of the n^th-CASAM-L in the quest …

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): I. Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the mathematical framework of the n^th-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Response-Coupled Forward/Adjoint Linear Systems (abbreviated as “n^th-CASAM-L”), which is conceived for obtaining the exact expressions of arbitrarily-high-order (n^th-order) sensitivities of a generic system response with respect to all of the parameters (including boundary and initial conditions) underlying the respective forward/adjoint systems. Since many of the most important responses for linear systems involve the solutions of both the forward and the adjoint linear models that correspond to the respective physical system, the sensitivity analysis of such responses makes it necessary …

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): I. Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the mathematical framework of the n^th-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Response-Coupled Forward/Adjoint Linear Systems (abbreviated as “n^th-CASAM-L”), which is conceived for obtaining the exact expressions of arbitrarily-high-order (n^th-order) sensitivities of a generic system response with respect to all of the parameters (including boundary and initial conditions) underlying the respective forward/adjoint systems. Since many of the most important responses for linear systems involve the solutions of both the forward and the adjoint linear models that correspond to the respective physical system, the sensitivity analysis of such responses makes it necessary …

Simultaneous Dirac-Like Cones At Two Energy States In Tunable Phononic Crystals: An Analytical And Numerical Study, Mustahseen M. Indaleeb, Sourav Banerjee

Faculty Publications

Simultaneous occurrence of Dirac-like cones at the center of the Brillouin zone (Γ) at two different energy states is termed Dual-Dirac-like cones (DDC) in this article. The occurrence of DDC is a rare phenomenon. Thus, the generation of multiple Dirac-like cones at the center of the Brillouin zone is usually non-manipulative and poses a challenge to achieve through traditional accidental degeneracy. However, if predictively created, DDC will have multiple engineering applications with acoustics and vibration. Thus, the possibilities of creating DDC have been identified herein using a simple square periodic array of tunable square phononic crystals (PnCs) in air media. …

Modeling Electrokinetics Of Oxygen Electrodes In Solid Oxide Electrolyzer Cells, Korey Cook, Jacob Wrubel, Zhiwen Ma, Kevin Huang, Xinfang Jin

Faculty Publications

A microscale model is presented in this study to simulate electrode kinetics of the oxygen electrode in a solid oxide electrolyzer cell (SOEC). Two mixed ionic/electronic conducting structures are examined for the oxygen producing electrode in this work: single layer porous lanthanum strontium cobalt ferrite (LSCF), and bilayer LSCF/SCT (strontium cobalt tantalum oxide) structures. A yttrium-stabilized zirconia (YSZ) electrolyte separates the hydrogen and oxygen electrodes, as well as a gadolinium doped-ceria (GDC) buffer layer on the oxygen electrode side. Electrochemical reactions occurring at the two-phase boundaries (2PBs) and three-phase boundaries (3PBs) of single-layer LSCF and bilayer LSCF/SCT oxygen electrodes are …

An Optimized Machine Learning And Big Data Approach To Crime Detection, Ashokkumar Palanivinayagam, Siva Shankar Gopal, Sweta Bhattacharya, Noble Anumbe, Ebuka Ibeke, Cresantus Biamba

Faculty Publications

Crime detection is one of the most important research applications in machine learning. Identifying and reducing crime rates is crucial to developing a healthy society. Big Data techniques are applied to collect and analyse data: determine the required features and prime attributes that cause the emergence of crime hotspots. The traditional crime detection and machine learning-based algorithms lack the ability to generate key prime attributes from the crime dataset, hence most often fail to predict crime patterns successfully. This paper is aimed at extracting the prime attributes such as time zones, crime probability, and crime hotspots and performing vulnerability analysis …

An Efficient Track-Scale Model For Laser Powder Bed Fusion Additive Manufacturing: Part 1- Thermal Model, Reza Tangestani, Trevor Sabiston, Apratim Chsktsborty, Waqas Muhammad, Lang Yuan, Étienne Martin

Faculty Publications

This is the first of two manuscripts that presents a computationally efficient full field deterministic model for laser powder bed fusion (LPBF). A new Hybrid Line (HL) heat input model integrates an exponentially decaying (ED) heat input over a portion of a laser path to significantly reduce the computational time. Experimentally measured properties of the high gamma prime nickel-based superalloy RENÉ 65 are implemented in the model to predict the in-process temperature distribution, stresses, and distortions. The model accounts for specific properties of the material as different phases. The first manuscript presents the HL heat transfer model, which is compared …

An Efficient Track-Scale Model For Laser Powder Bed Fusion Additive Manufacturing: Part 2-Mechanical Model, Reza Tangestani, Trevor Sabiston, Apratim Chakraborty, Lang Yuan, Nicholas Krutz, Étienne Martin

Faculty Publications

This is the second of two manuscripts that presents a computationally efficient full-field deterministic model for laser powder bed fusion (LPBF). The Hybrid Line (HL) thermal model developed in part I is extended to predict the in-process residual stresses due to laser processing of a nickel-based superalloy, RENÉ 65. The computational efficiency and accuracy of the HL thermo-mechanical model is first compared to the exponential decaying heat input model on a single-track simulation. LPBF thin-wall builds with three different laser powers and four printing patterns are evaluated in this study and compared with part-scale simulations. The simulations show good agreements …

Meshfree Simulation And Experimental Validation Of Extreme Thermomechanical Conditions In Friction Stir Extrusion, Lei Li, Varun Gupta, Xiao Li, Anthony P. Reynolds, Glenn Grant, Ayoub Soulami

Faculty Publications

Friction stir extrusion (FSE) is a novel solid-phase processing technique that consolidates and extrudes metal powders, flakes, chips, or billets into high-performance parts by plastic deformation, which has the potential to save substantial processing time and energy. Currently, most studies on FSE are experimental and only a few numerical models have been developed to explain and predict the complex physics of the process. In this work, a meshfree simulation framework based on smoothed particle hydrodynamics (SPH) was developed for FSE. Unlike traditional grid-based methods, SPH is a Lagrangian particle-based method that can handle severe material deformations, capture moving interfaces and …

Evaluation Of Orthogonal Strain Components In Friction Extrusion, X Li, Md. Reza-E Rabby, M Ryan, G. Grant, Anthony P. Reynolds

Faculty Publications

Friction extrusion is a thermomechanical process that combines conventional extrusion with the action of a rotating die. The plastic deformation of the material being sheared and extruded is the primary source of process heat and it produces strain distributions unlike those resulting from conventional extrusion. This paper proposes an improved strain analysis that evaluates three main strain components in a series of rate-controlled friction extrusions in which the steady state was achieved. Cylindrical AA1100 extrusion billets with two embedded markers were extruded to wire with a 10:1 diametral reduction. The shape change of the embedded markers was determined via serial, …

Soft Elastomeric Capacitor For Angular Rotation Sensing In Steel Components, Han Liu, Simon Laflamme, Jian Li, Caroline Bennett, William N. Collins, Austin Downey, Paul Ziehl, Hongki Jo

Faculty Publications

The authors have previously proposed corrugated soft elastomeric capacitors (cSEC) to create ultra compliant scalable strain gauges. The cSEC technology has been successfully demonstrated in engineering and biomechanical applications for in-plane strain measurements. This study extends work on the cSEC to evaluate its performance at measuring angular rotation when installed folded at the junction of two plates. The objective is to characterize the sensor’s electromechanical behavior anticipating applications to the monitoring of welded connections in steel components. To do so, an electromechanical model that maps the cSEC signal to bending strain induced by angular rotation is derived and adjusted using …

Parameter Estimation And Application Of Anisotropic Yield Criteria For Cylindrical Aluminum Extrusions: Theoretical Developments And Stereodic Measurements, Farzana Yasmeen, Michael A. Sutton, Xiaomin Deng, Megan Ryan, Anthony P. Reynolds

Faculty Publications

Theoretical and experimental studies are presented to characterize the anisotropic plastic response under torsion loading of two nominally identical aluminum Al6061-T6 extruded round bars. Theoretical models are developed using isotropic (Von Mises 1913) and anisotropic (Barlat 1991) yield criteria, along with isotropic strain hardening formulae, to model post-yield behavior under simple torsion loading. For the case of simple shear loading, incremental plasticity theory is used to determine the theoretical elastic, plastic, and total shear strains. A set of experiments are performed to calibrate Barlat’s 1991 yield function. Several specimens are extracted at different orientations to the longitudinal direction of each …

High-Order Deterministic Sensitivity Analysis And Uncertainty Quantification: Review And New Developments, Dan Gabriel Cacuci

Faculty Publications

This work reviews the state-of-the-art methodologies for the deterministic sensitivity analysis of nonlinear systems and deterministic quantification of uncertainties induced in model responses by uncertainties in the model parameters. The need for computing high-order sensitivities is underscored by presenting an analytically solvable model of neutron scattering in a hydrogenous medium, for which all of the response’s relative sensitivities have the same absolute value of unity. It is shown that the wider the distribution of model parameters, the higher the order of sensitivities needed to achieve a desired level of accuracy in representing the response and in computing the response’s expectation, …

On The Need To Determine Accurately The Impact Of Higher-Order Sensitivities On Model Sensitivity Analysis, Uncertainty Quantification And Best-Estimate Predictions, Dan Gabriel Cacuci

Faculty Publications

This work aims at underscoring the need for the accurate quantification of the sensitivities (i.e., functional derivatives) of the results (a.k.a. “responses”) produced by large-scale computational models with respect to the models’ parameters, which are seldom known perfectly in practice. The large impact that can arise from sensitivities of order higher than first has been highlighted by the results of a third-order sensitivity and uncertainty analysis of an OECD/NEA reactor physics benchmark, which will be briefly reviewed in this work to underscore that neglecting the higher-order sensitivities causes substantial errors in predicting the expectation and variance of model responses. The …