Mechanical Engineering Commons^™

Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies, Easton Ingram, Emmanuela Amen Eze, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith particles with applications to the concept of electrostatic sieving. The new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. Case studies for a concept of electrostatic sieving were chosen to validate the new model. The simulation achieved similar yields reported in previous works, which served as validation of the model. The new model is computationally efficient and could serve as a design, analysis, and optimization tool.

Impact Of Quenching Intensity Conditions On Using A Finite Element Model To Investigate The Microstructure And Hardenability Of Low-Alloy Steel, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

Quenching is one of the primary processes to improve mechanical properties in steels, particularly hardness. Quenching is well established for different geometries of individually treated steel components; while in-steam quenching of large diameter continuously cast steel bar has several specific features which are difficult and costly to experimentally optimize. The end-quench Jominy test has been used extensively to study the hardenability of different steel grades. Different numerical, analytical, and empirical models have been developed to simulate the Jominy process and to understand quenching of steels. However, it is not straight forward to translate experimental data from Jominy test on instream …

Magnetic Separation Of Lunar Regolith Simulants With Applications To In Situ Resource Utilization On The Moon, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

The development of in situ resource utilization (ISRU) for metal extraction is imperative as a steppingstone for habitation construction in lunar and non-terrestrial environments. Separation of minerals by chemical composition is important to optimize metal and oxygen liberation from lunar ore. to this effect, devices capable of separating aluminum bearing minerals from iron-bearing minerals from the lunar regolith simulants have been developed. Twenty-eight different simulants have been used in this study. a dual-belt separator was designed to reduce middlings. Para-magnetic minerals were reliably separated using a neodymium N52-magnet-separator system. Effective separation of aluminum-bearing minerals from iron-bearing minerals was greater than …

Impact Of Quenching Intensity Conditions On Using A Finite Element Model To Investigate The Microstructure And Hardenability Of Low-Alloy Steel, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

Quenching is one of the primary processes to improve mechanical properties in steels, particularly hardness. Quenching is well established for different geometries of individually treated steel components; while in-steam quenching of large diameter continuously cast steel bar has several specific features which are difficult and costly to experimentally optimize. the end-quench Jominy test has been used extensively to study the hardenability of different steel grades. Different numerical, analytical, and empirical models have been developed to simulate the Jominy process and to understand quenching of steels. However, it is not straight forward to translate experimental data from Jominy test on instream …

A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a concept of producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method developed at Missouri University of Science and Technology. This paper aims to demonstrate the use of electro-deoxidation to reduce aluminum oxide (i.e., alumina) into aluminum and oxygen gas via electrolysis in a molten salt bath for the production of aluminum on the Moon. It is shown that with a steady supply of hydrogen chloride, this in-situ resource utilization (ISRU) method could supply several necessary materials consumed in the electro-deoxidation process except hydrogen chloride to produce …

Advanced Manufacturing Of Nanomaterials For Energy Storage And Biomedical Applications, Hiep Pham

Doctoral Dissertations

"Nanomaterials have emerged as an important component to the advancement of many fields, ranging from advanced energy materials in the energy field to highly sophisticated treatment vehicles in the biomedical field. Understanding the physical behavior of nanomaterials is critical to design materials with excellent properties and performance for the many disciplines in which they are utilized and is necessary to master the various manufacturing processes that influence nanomaterial properties and behavior. This research focused on a fundamental study into the behaviors of newly developed nanomaterials under both conventional and new manufacturing processes for high performance lithium-ion batteries and for advanced …

Melt Pool Feature Extraction, A State-Space Model And Spatial Layer-To-Layer Control For Powder Bed Fusion, Xin Wang

Doctoral Dissertations

"Powder Bed Fusion (PBF) is an Additive Manufacturing (AM) technique which can reduce material waste and is a fast-prototyping technique for complex geometries. However, the lack of consistent quality is a major problem in industrial applications. An InfraRed (IR) camera is a common tool to monitor a surface temperature field and melt pool morphology in PBF. With melt pool features from camera videos, manufacturing researchers use spatial feature maps to visualize defect locations and control researchers use layer-to-layer control to achieve more uniform melt pools and less defects.

Paper I presents a simulation method to characterize the effect of down-sampling …

Material Models For Simulation Of Steel Hot Rolling Process Using Experimentally Determined Properties At Elevated Temperatures And Strain Rates, Siva Sai Krishna Dasari

Doctoral Dissertations

"Hot rolling is one of the most important and complex process that includes large material deformation, different contact conditions, complex geometries and different temperature gradients along with micro structural changes such as viscoplasticity, dynamic recrystallization, and static softening. In the present work, the viscoplasticity, damage evolution, static softening and void closure of alloyed metal during hot rolling process was numerically investigated. Gleeble^TM hot compression and double hit tests were performed to provide experimental stress-strain curves at recrystallization temperatures and at different strain rates. Johnson-Cook viscoplastic model was calibrated using experimental stress-strain curves. Static softening model was developed at varying …

Additive Manufacturing Of Steel And Aluminum Structures: Modeling And Experiments, Manoj Kumar Reddy Rangapuram

Doctoral Dissertations

"Additive manufacturing (AM) is defined as the process of joining materials to make objects from three-dimensional model data. Complex geometries can be easily manufactured compared to conventional subtractive methods with more freedom and flexibility in the design process. As the demand for AM process increased, it has become critical to understand the process and various parameters that constitute in affecting the quality of the manufactured part. Conducting experiments can be time intensive and costly to optimize a process. Modeling can be used as an aid to optimize, examine, and predict the process outcome.

The objective of this study is (i) …

Methodology For Parameter Determination For Simulation Software, Aaron Flood

Doctoral Dissertations

"This research aims to present a methodology for optimizing input datasets to increase the accuracy of mathematical models and accelerate their application to engineering problems. To accomplish this goal, this work focused on the application of mathematical models to metal additive manufacturing (AM), specifically the thermal history of laser directed energy deposition (DED) of aluminum alloys. The initial steps of this body of work were to develop a mathematical model that is capable of simulating the metal AM process and applying it to the laser DED of aluminum. It was validated using the well characterized material Ti-64 and shown to …

Kinetic Modeling And Simulations Of Plasma-Surface-Dust Interactions For Lunar Exploration, David Clifford Lund

Doctoral Dissertations

"Due to the recent relevance of NASA’s focus on lunar missions, a better understanding of the lunar plasma-surface-dust environment is vital for their success. The lunar surface, devoid of an atmosphere and a global magnetic field, is directly exposed to solar radiation and solar wind plasma. This exposure leads to the electrical charging of the lunar surface due to the bombardment of solar wind plasma and the emission/collection of photoelectrons. Therefore, this research developed accurate and efficient computational models of plasma-surface-dust interactions and extend a legacy simulation code, namely the Immersed-Finite-Element Particle-in-Cell (IFE-PIC), to a parallel version: Parallel Immersed-Finite-Element Particle-in-Cell …

In Situ Infrared Thermographic Inspection In Additive Manufacturing, Tao Liu

Doctoral Dissertations

"Laser Powder Bed Fusion (LPBF) is a key technique in metal additive manufacturing and has undergone extensive research over the past few decades. It enables the fabrication of complex geometries directly from digital design models. The solidification process in LPBF is heavily influenced by the characteristics of the powder layer, including its thickness and thermal transport properties. Additionally, the performance of the printed part is impacted by the temperature history during solidification and the final residual stress field. While these topics have been the focus of many studies, almost all research has concentrated on ex-situ measurement and testing. These ex-situ …

Optimizing The Total Life Cycle Of Li-Ion Batteries: From Constant Gradient Charging To Aged Cell Performance Restoration, Kasim Adesegun Adewuyi

Doctoral Dissertations

As demand for Lithium-Ion Batteries (LIBs) have skyrocketed over the past decade, the need for better charging methodologies and recycling methods have become vitally important. At a fundamental level, this dissertation strives to fulfill the green promise of a future without fossil fuels. In order to promote a transition away from fossil fuels, LIBs for vehicles require ultrafast charging times equivalent to a normal vehicle (6 mins). However, this process leads to high volume expansion for next generation electrode materials which causes degradation. Without limiting this factor, the environmental impact shifts from oil rigs to Li mines and landfills. The …

Communication Modality And Activity Recognition In Smart Manufacturing, Haodong Chen

Doctoral Dissertations

"Advancements in sensors, computational intelligence, and big data have been rapidly transforming and revolutionizing the manufacturing sector, leading to robot-rich and digitally connected factories. To facilitate such a transformative process, workforce training and coordination between the human workforce and robots have remained a major challenge. This study aims to create intelligent workforce training systems for human-computer interaction and human-robot collaboration. It proposes the use of dynamic gestures and speech commands for seamless communication between a worker and a robot, leveraging Convolutional Neural Networks (CNN) and multiple threading for recognition and integration. Additionally, a fine-grained activity recognition model has been crafted …

Effect Of Ai–Si Coating Weights On Corrosion And Weldability Of Ultra-High-Strength Steel Usiborr 1500 Used In Automotive Structures, Hilary Anayochukwu Onyishi

Doctoral Dissertations

"There has been increased demand for hot-stamped pre-coated Usibor 1500R in automotive industries due to its excellent properties (ultra-high strength, weight reduction, low spring back and excellent corrosion protection). In this research work, investigation was conducted to better understand the effect of Ai-Si Coating Weights on weldability and corrosion of Ultra-High-Strength Steel Usibor 1500R used in Automotive Structures”. The results show that weld nugget diameter increases with increasing weld current, better spot-weld nugget diameter is recorded at weld currents above 7.5 kA for both AS80 and AS150 and the weld current range decreases as the interdiffusion layer (IDL) thickness increases. …

The Role Of Atomic Layer Deposited Coatings On Lithium-Ion Transport: A Comprehensive Study, Yufang He, Hiep Pham, Xinhua Liang, Jonghyun Park

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Use of Ultrathin Film Coatings Prepared through Atomic Layer Deposition (ALD) Has Become Widespread for Improving Lithium-Ion Diffusivity of Active Particles, Which Plays a Crucial Role in Determining the Rate Capability of Lithium-Ion Batteries (LIBs). in This Study, the Impact of ALD Coating Thickness on Ionic Diffusivity in CeO2-Coated LiMn2O4 (LMO) Cathode Particles is Comprehensively Investigated through First-Principles Calculations by Focusing on the Trade-Offs between the Physical Properties of the Film and its Impact on the Diffusivity of Ions. Our Findings Indicate that Several Physical Factors Affect the Diffusivity of the Coating, Including the Crystal-Amorphous Structure that Depends on …

Microstructure, Mechanical Properties And Oxidation Behavior Of Refractory Multi-Principal Element Alloys By Laser Remelting And Conventional Manufacturing, Visharad Jalan, Seth Crawford, Sung Heng Wu, Frank Liou, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Refractory multi-principal element alloys (RMPEAs), HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al, were manufactured using vacuum arc melting followed by laser remelting to mimic additive manufacturing. the microhardness of the as-cast HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al samples after arc melting was measured as 6.20, 7.63, and 6.89 Gpa, respectively. after laser remelting and re-solidification, the hardness increased by ~ 30% for each composition; the hardest was (HfNbTaTiZr)9Cr measured at 9.60 GPa, while the softest was HfNbTaTiZr with a hardness of 8.42 GPa, which was still harder compared to all the other samples. the addition of Al and Cr led to enhanced oxidation resistance for …

Effects Of Simultaneous Co2 Addition To The Fuel And Oxidizer Streams On Soot Formation In Co-Flow Diffusion Ethylene Flame, Yu Yang, Shu Zheng, Yuzhen He, Hao Liu, Ran Sui, Qiang Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Soot formation in a co-flow diffusion ethylene flame with the addition of CO₂ to the fuel (the CO₂-F), oxidizer (the CO₂-O), and fuel/oxidizer (the CO₂-F/O) streams was numerically and experimentally investigated in this study. The effects of different CO₂ addition ways on soot inception, soot condensation, H-abstraction-C₂H₂-addition (HACA) and oxidation by O₂/OH processes, were quantitatively analyzed by introducing the integrated reaction rates over the whole computational domain. The simulated and experimental results showed that the CO₂-F/O was the most effective in inhibiting soot formation …

Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microstructural changes and softening due to static recrystallization have a critical influence on thermo-mechanical behavior of high strength steels during industrial multi-pass hot rolling. Numerical simulation using finite element analysis (FEA) can be used to accurately predict the softening behavior during the hot rolling process. Therefore, the implementation of an experimentally defined static recrystallization model into FEA is necessary to get realistic simulation prediction. in this study, the extent of softening during static recrystallization in Si and Mn alloyed high strength steel was measured using double hit tests. a Gleeble™ thermo-mechanical simulator was used to perform the double hit tests …

Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured steels are expected to have enhanced irradiation tolerance and improved strength. However, they suffer from poor microstructural stability at elevated temperatures. in this study, Fe–21Cr–5Al–0.026C (wt.%) Kanthal D (KD) alloy belonging to a class of (FeCrAl) alloys considered for accident-tolerant fuel cladding in light-water reactors is nanostructured using two severe plastic deformation techniques of equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), and their thermal stability between 500–700 °C is studied and compared. ECAP KD is found to be thermally stable up to 500 °C, whereas HPT KD is unstable at 500 °C. Microstructural characterization reveals that ECAP KD …

Design Of Impact-Free Gaits For Planar Bipeds And Their Stabilization Using Impulsive Control, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of designing and stabilizing impact-free gaits is considered for point-foot planar bipeds. A set of geometric constraints, which eliminate impact forces at the time of leg interchange, are used to design the gaits. A family of gaits, where the stride length and walking speed can be chosen independently for each gait, is guaranteed to exist. A continuous controller is used to enforce the constraints associated with a desired gait and intermittent impulsive inputs are applied to stabilize the gait. A five-link biped example is used to illustrate the procedure for designing impact-free gaits. The effectiveness of the continuous …

Searching For Unknown Material Properties For Am Simulations, Aaron Flood, Rachel Boillat, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive manufacturing (AM) simulations are effective for materials that are well characterized and published; however, for newer or proprietary materials, they cannot provide accurate results due to the lack of knowledge of the material properties. This work demonstrates the process of the application of mathematical search algorithms to develop an optimized material dataset which results in accurate simulations for the laser directed energy deposition (DED) process. This was performed by first using a well-characterized material, Ti-64, to show the error in the predicted melt pool was accurate, and the error was found to be less than two resolution steps. Then, …

Atomic Insights Into The Structural Properties And Displacement Cascades In Ytterbium Titanate Pyrochlore (Yb2ti2o7) And High-Entropy Pyrochlores, M. Mustafa Azeem, Qingyu Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pyrochlore oxides ((Formula presented.) are potential nuclear waste substrate materials due to their superior radiation resistance properties. We performed molecular dynamics simulations to study the structural properties and displacement cascades in ytterbium titanate pyrochlore ((Formula presented.)) and high-entropy alloys (HEPy), e.g., (Formula presented.), (Formula presented.), and (Formula presented.). We computed lattice constants (LC) ((Formula presented.)) and threshold displacement energy (Ed). Furthermore, the calculation for (Formula presented.) and ionic radius ((Formula presented.)) were performed by substituting a combination of cations at the A and B sites of the original pyrochlore structure. Our simulation results have demonstrated that the lattice constant is …

The Investigation Of A Likely Scenario For Natural Tornado Genesis And Evolution From An Initial Instability Profile, Alexios Nicolas Philippou, Kakkattukuzhy M. Isaac

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …

From A Single Grain To Microstructure: How Explosive Grains Interact Under Shock Compression, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We studied the effect of varying the HMX concentration in a plastic-bonded explosive (PBX) by analyzing the time-dependent thermal emission with short (4 ns) duration shocks that produced pressures of about 20 GPa. We found that the HMX tended to aggregate even at the lowest concentrations. Once the cluster size reached about 15 μm, at 30 wt.%, the cluster size started increasing more dramatically, but energy release during deflagration reached a plateau. These observations are consistent with the idea that the clusters act as a limiting factor for hot spot criticality, possibly due to heat loss mechanisms such as conduction …

Porosity: The Key To Initiating Metallic Composite Particles Under Shock Compression, Siva Kumar Valluri, Edward L. Dreizin, Dana D. Dlott

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The use of metallic composites as additives can potentially improve the energy density of explosives. Before employing them as additives it is imperative to design composites with physically separated metal fuel and oxidizer that can combust on short time scales, tens of nanoseconds, similar to high-performance molecular explosives. Towards that end, sensitizing composite powder particles to shock compression is crucial. In the current work, particle porosity is explored as means to induce hotspot formation within the particle through pore-collapse. Particles of two porous powders, Al-MoO3-KNO3 (equivalence ratio 3) and Al-CuO (equivalence ratio 4) prepared by arrested reactive milling with emulsion …

Seeing Inside Shocked Plastic-Bonded Explosives, Dhanalakshmi Sellan, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott, Xuan Zhou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new method is described to study how microstructures within a plastic-bonded explosive (PBX) interact with shock waves to produce hot spots, and to identify the critical hot spots that grow into a deflagration. A unique feature of this method is that it allows us to see every crystal in the PBX during the shock. We used an HMX-based PBX fabricated into a wafer about one crystal thick so there are no crystals hidden from view. The wafer is embedded in a transparent polymer in a traveling wave geometry, and a microscope with a laser flyer launcher and a nanosecond …

Stochastic Modeling Of Physical Drag Coefficient – Its Impact On Orbit Prediction And Space Traffic Management, Smriti Nandan Paul, Phillip Logan Sheridan, Richard J. Licata, Piyush M. Mehta

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ambitious satellite constellation projects by commercial entities and the ease of access to space in recent times have led to a dramatic proliferation of low-Earth space traffic. It jeopardizes space safety and long-term sustainability, necessitating better space domain awareness (SDA). Correct modeling of uncertainties in force models and orbital states, among other things, is an essential part of SDA. For objects in the low-Earth orbit (LEO) region, the uncertainty in the orbital dynamics mainly emanate from limited knowledge of the atmospheric drag-related parameters and variables. In this paper, which extends the work by Paul et al. (2021), we develop a …

In-Situ Lock-In Thermographic Measurement Of Powder Layer Thermal Diffusivity And Thickness In Laser Powder Bed Fusion, Tao Liu, Edward C. Kinzel, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The thermal transport properties of the powder layer play a crucial role in the process of laser powder bed fusion (LPBF). This paper introduces an in-situ measurement method utilizing active lock-in infrared thermography (LIT) to determine the thermal diffusivity and thickness of the powder layer. The proposed method exhibits great potential for accurate powder property and thickness measurements and real-time process monitoring. In this lock-in thermographic technique, the LPBF laser beam is directed through an optical diffuser and modulated into a square thermal wave. This thermal wave serves as an active heat source to heat the surface of the powder …

A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario Buchely, Ronald O'Malley, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Most of the face-centered cubic (FCC) multi-principal element alloys (MPEAs) developed thus far contain cobalt. for many applications, it is either required or beneficial to avoid cobalt, since cobalt has long-term activation issue (for nuclear applications), is expensive, and is considered a critical material. in addition, FCC structured solid-solution MPEAs tend to have relatively low strength. an FCC solid-solution Fe30Ni30Mn30Cr10 (at %) MPEA was fabricated via arc melting, followed by homogenization at 1100 °C for 12 h. the alloy was hot rolled at 1100 °C with a total reduction of up to 97 %. the microstructure was characterized, and mechanical …