Mechanical Engineering Commons^™

Iterative Learning Control Of Single Point Incremental Sheet Forming Process Using Digital Image Correlation, Joseph D. Fischer, Mitchell R. Woodside, Mercedes M. Gonzalez, Nathan A. Lutes, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Single Point Incremental Sheet Forming (SPIF) is a versatile forming process that has gained significant traction over the past few decades. Its increased formability, quick part adaption, and reduced set-up costs make it an economical choice for small batch and rapid prototype forming applications when compared to traditional stamping processes. However, a common problem with the SPIF process is its tendency to produce high geometric error due to the lack of supporting dies and molds. While geometric error has been a primary focus of recent research, it is still significantly larger for SPIF than traditional forming processes. In this paper, …

Nanoparticle Injector For Photonic Manipulators Using Dielectrophoresis, Jaykob Maser, Joshua Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We describe the concept of a dielectrophoretic nanoparticle injector and its use in a plasmonic/photonic-based nanoparticle manipulation system. Particle motion is achieved by generating an electrostatic, non-uniform field between two tilted plates and applying the corresponding dielectrophoretic force to net-neutral nanoparticles. We investigate the dependence the dielectrophoretic force has on the plate angle of the charged plates as well as their separation distance, dielectric filler material, and exit interface membrane. Our results indicate an increasing average and maximum dielectrophoretic force attainable in the axial direction with corresponding decreasing plate angle and gap distance. The model also predicts larger field variation …

Bulk-Explosion-Induced Metal Spattering During Laser Processing, Cang Zhao, Qilin Guo, Xuxiao Li, Niranjan Parab, Kamel Fezzaa, Wenda Tan, Lianyi Chen, Tao Sun

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Spattering has been a problem in metal processing involving high-power lasers, like laser welding, machining, and recently, additive manufacturing. Limited by the capabilities of in situ diagnostic techniques, typically imaging with visible light or laboratory x-ray sources, a comprehensive understanding of the laser-spattering phenomenon, particularly the extremely fast spatters, has not been achieved yet. Here, using MHz single-pulse synchrotron-x-ray imaging, we probe the spattering behavior of Ti-6Al-4V with micrometer spatial resolution and subnanosecond temporal resolution. Combining direct experimental observations, quantitative image analysis, as well as numerical simulations, our study unravels a novel mechanism of laser spattering: The bulk explosion of …

A Hybrid Process Integrating Reverse Engineering, Pre-Repair Processing, Additive Manufacturing, And Material Testing For Component Remanufacturing, Xinchang Zhang, Wenyuan Cui, Wei Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metallic components can gain defects such as dents, cracks, wear, heat checks, deformation, etc., that need to be repaired before reinserting into service for extending the lifespan of these parts. In this study, a hybrid process was developed to integrate reverse engineering, pre-repair processing, additive manufacturing, and material testing for the purpose of part remanufacturing. Worn components with varied defects were scanned using a 3D scanner to recreate the three-dimensional models. Pre-repair processing methods which include pre-repair machining and heat-treatment were introduced. Strategies for pre-repair machining of defects including surface impact damage, surface superficial damage and cracking were presented. Pre-repair …

Controlling Structures Of Battery Electrodes, Jonghyun Park, Jie Li

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Manufacturing an electrode by forming an electrode structure on a grounded conductive substrate and applying a voltage across the electrode structure to generate an electric field through the electrode structure to arrange the dipolar particles within the electrode structure.

Mass Accommodation At A High-Velocity Water Liquid-Vapor Interface, J. Nie, A. Chandra, Z. Liang, P. Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We Use Molecular Dynamics to Determine the Mass Accommodation Coefficient (MAC) of Water Vapor Molecules Colliding with a Rapidly Moving Liquid-Vapor Interface. This Interface Mimics Those Present in Collapsing Vapor Bubbles that Are Characterized by Large Interfacial Velocities. We Find that at Room Temperature, the MAC is Generally Close to Unity, and Even with Interfaces Moving at 10 Km/s Velocity, It Has a Large Value of 0.79. using a Simplified Atomistic Fluid Model, We Explore the Consequences of Vapor Molecule Interfacial Collision Rules on Pressure, Temperature, and Density of a Vapor Subjected to an Incoming High-Velocity Liquid-Vapor Interface.

Method And Apparatus For Fabricating Ceramic And Metal Components Via Additive Manufacturing With Uniform Layered Radiation Drying, Ming-Chuan Leu, Amir Ghazanfari, Wenbin Li, Greg Hilmas, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A freeform extrusion fabrication process for producing three - dimensional ceramic, metal and functionally gradient composite objects, including the steps of filling a plurality of paste sources with a respective plurality of aqueous paste compositions, operationally connecting respective syringes containing respective aqueous paste compositions to a mix ing chamber, moving a first aqueous paste composition from a first respective paste source into the mixing chamber, moving a second aqueous paste composition from a second respective paste source into the mixing chamber, mixing the first and second aqueous paste compositions to define a first admixture having a first admixture composition, extruding …

A Comparison Of Static And Dynamic Functional Connectivities For Identifying Subjects And Biological Sex Using Intrinsic Individual Brain Connectivity, Sreevalsan S. Menon, K. Krishnamurthy

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Functional magnetic resonance imaging has revealed correlated activities in brain regions even in the absence of a task. Initial studies assumed this resting-state functional connectivity (FC) to be stationary in nature, but recent studies have modeled these activities as a dynamic network. Dynamic spatiotemporal models better model the brain activities, but are computationally more involved. A comparison of static and dynamic FCs was made to quantitatively study their efficacies in identifying intrinsic individual connectivity patterns using data from the Human Connectome project. Results show that the intrinsic individual brain connectivity pattern can be used as a ‘fingerprint’ to distinguish among …

Manipulating Transverse Photovoltage Across Plasmonic Triangle Holes Of Symmetry Breaking, Marjan Akbari, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The transverse photo-induced voltages generated by the photon drag effect under normally and obliquely incident circularly polarized light across the plasmonic symmetry-breaking isosceles-triangle holes and right-triangle holes have been characterized. It is observed that the sign of transverse photovoltage flips when the incident circular polarization is switched for both types of plasmonic triangle holes. However, the unbalanced photovoltage between two circular polarizations is achieved across the plasmonic right-triangle holes, compared to the balanced photovoltage in the plasmonic isosceles-triangle holes. Such manipulation of the sign and the amplitude of transverse photovoltage is enabled by the broken symmetries of the electric and …

Optical Transportation And Accumulation Of Microparticles By Self-Accelerating Cusp Beams, Weiwei Liu, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Most of the self-accelerating beams have monotonous single-channel bending structures, which greatly limit their applications in many fields such as microscopic imaging and particle manipulation. In this paper, the self-accelerating cusp beams with variable numbers of multichannel bending structures are generated to demonstrate the optical transportation and accumulation of micrometer polystyrene particles. The transportation velocity and optical force profiles of the microparticles moving along the bending channels of cusp beams are analyzed. Parallel particle transportation and particle accumulation manipulation from all the bending channels are further demonstrated. These results will inspire a lot of promising applications for self-accelerating beams especially …

Design And Fabrication Of Automatic Single Axis Solar Tracker For Solar Panel, Ghazanfar Mehdi, Naveed Ali, Shafquat Hussain, Asad A. Zaidi, Ahmer Hussain Shah, M. Mustafa Azeem

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sun energy is a considered to be one of most promising sources to address the world energy crises. Photovoltaic cell is one of the prominent sources of energy. The most important factors that affect the efficiency of solar cells are cell temperature, maximum power point tracking (MPPT) and energy conversion efficiency. The optimization of these factors improves solar cells efficiency for more reliable applications. This study associated by means of the designing and manufacturing process of single axis tracker device by using photo voltaic conversion panels. This solar tracker system assures the conversion optimization of electricity from the source of …

On The Feasibility Of Tailoring Copper-Nickel Functionally Graded Materials Fabricated Through Laser Metal Deposition, Sreekar Karnati, Yunlu Zhang, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, pulse‐width modulation of laser power was identified as a feasible means for varying the chemical gradient in copper—nickel‐graded materials. Graded material deposits of 70 wt. %. copper‐30 wt. %. nickel on 100 wt. %. nickel and vice versa were deposited and characterized. The 70/30 copper—nickel weight ratio in the feedstock powder was achieved through blending elemental copper and 96 wt. %. Ni—Delero‐22 alloy. At the dissimilar material interface over the course of four layers, the duty cycle of power was ramped down from a high value to optimized deposition conditions. This change was theorized to influence the …

Cutter Elements For Drill Bits And Methods For Fabricating Same, Guodong Zhan, Biju Pillai Kumar, Russell C. Gilleylen, Michael D. Hughes, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A method of fabricating a PCD cutter element including a diamond table including a plurality of coated diamond particles fabricated using an atomic layer deposition (ALD) process.

Substrate Support Ring For More Uniform Layer Thickness, Heng Pan, Lara Hawrylchak, Christopher S. Olsen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Embodiments of substrate support rings providing more uniform thickness of layers deposited or grown on a substrate are provided herein. In some embodiments, a substrate support ring includes: an inner ring with a centrally located support surface to support a substrate; and an outer ring extending radially outward from the support surface, wherein the outer ring comprises a reaction surface area disposed above and generally parallel to a support plane of the support surface, and wherein the reaction surface extends beyond the support surface by about 24 mm to about 45 mm.

Fluorine-Containing Oxidizers For Metal Fuels In Energetic Formulations, Siva Kumar Valluri, Mirko Schoenitz, Edward Dreizin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fluorine containing oxidizers, primarily polymers, are extensively used in pyrotechnic compositions. Fluorinated oxidizers are less explored for metalized propellants and explosives despite a potential advantage of substantial heat release combined with gaseous combustion products. This review summarizes different types of fluorinated oxidizers used in energetic formulations or of potential interest for such systems, including gases, polymers, and inorganic compounds. Types of energetic formulations employing metals and fluoropolymers are discussed in more detail, including methods used to prepare composites and resulting salient features of the obtained materials. Laboratory experiments characterizing such materials, in particular, electron microscopy and thermal analysis, are discussed, …

A Framework For Process Inspection Of Metal Additive Manufacturing, Chih-Kun Cheng, Frank W. Liou, Yi-Chien Cheng, Sheng-Chih Shen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we propose a process inspection framework for metal additive manufacturing (AM) processes. AM, also known as 3D printing, is the process of joining materials to make objects on the basis of 3D model data and is envisioned to play a strategic role in maintaining economic and scientific dominance. Different from conventional manufacturing methods, the AM process is a point-by-point and layer-by-layer manufacturing. Thus, there are many opportunities to generate a process error that can cause quality issues in an AM part. A systematic AM process inspection is needed to yield acceptable performance of the part. The critical …

Aerosol-Jet Printing And Flash Sintering Of Conformal Conductors On Non-Planar Surfaces, I-Meng Chen

Masters Theses

”The printed electronics have been broadly applied in our daily lives, many new manufacturing methodologies are studied and investigated. The research here presented the full manufacturing process of printed conductors of aerosol printing and flash sintering techniques on substrates such as planar and non-planar surfaces.

The aerosol printing (AJP) was introduced because of its simplicity in experimental setup and flexibility of printing. It produces less ink waste and consumes less manufacturing cost. Furthermore, it has the direct-write ability to print in any customized patterns or shapes on non-planar surfaces. In this study, the Cu NPs was selected as the functioning …

Determine Airborne Release Fractions (Arf) / Respirable Fractions (Rf) For Use In Safety Based Documents, Michael Quinn, Jacob Miller

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Atomistic Simulations Of Nanoindentation Response Of Irradiation Defects In Iron, M. Mustafa Azeem, Qingyu Wang, Muhammad Zubair

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Radiation response of a material is a consequence of defects' evolution in any radiation damage event. The radiation-induced defects can significantly alter the mechanical properties of a material. Radiation damage initiates from incident neutron by bombardment on solid material causing production and evolution of Frenkel defects. Since voids are formed due to aggregation of a large number of vacancies that cause dimensional changes and hence irradiation-induced swelling. In order to characterize the effect of irradiation defects, we have performed molecular dynamics (MD) simulations to investigate nanoindentation response of point defects and voids in Fe and their effects on mechanical parameters. …

Electric Solid Propellant Ablation In An Arc Discharge, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled, and extinguished) through the application and removal of an electric current. Electric solid propellants are also being considered for pulsed arc ablation electric thrusters, such as the pulsed plasma thruster. The focus of this work is the electrical and ablation characteristics of electric solid propellant within an arc discharge. Arc discharges of 5–20 J per pulse were created within a cylindrical cavity, and results for the electric solid propellant are compared with polytetrafluoroethylene (PTFE), which is a traditional propellant in ablative pulsed plasma thrusters. The …

Experimental Investigation Of Mixtures Of 1-Ethyl-3-Methylimidazolium Ethyl Sulfate And Ethylammonium Nitrate With Electrospray Propulsion Applications, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Physical properties, performance metrics, and mass spectra of mixtures of two ionic liquids (1-ethyl-3-methylimidazolium ethyl-sulfate aka [Emim][EtSO4] and ethyl ammonium nitrate aka EAN) are investigated from the standpoint of electrospray propulsive characteristics. Spectra suggest that as the [Emim][EtSO4] mixture fraction increases, the intensity of [Emim][EtSO4] related species in the plume also increases, while the presence of EAN decreases. Spectra also show presence of both EAN proton transfer species and species related to chemical reaction of [EtSO4] and water. Despite the volatility of EAN, it emits stably into vacuum at low flow rates when mixed with 25% [Emim][EtSO4]. Spectra also show …

Hydroxylammonium Nitrate Species In A Monopropellant Electrospray Plume, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince, Steven P. Berg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A mixture of 1-ethyl-3-methylimidazolium ethyl sulfate ([Emim][EtSO4]) and hydroxylammonium nitrate (HAN) is an energetic monopropellant potentially suitable in a multi-mode chemical-electric microtube-electrospray micro propulsion system. In this work, electrospray plume mass spectra are compared between the monopropellant mixture and neat [Emim][EtSO4]. This comparison clearly indicates new and additional species present in the plume due to the addition of HAN. Mass spectra from 20-600 amu/q were obtained over a variety of angles and flow rates from 2 pL/sec to 3 nL/sec in both cation and anion extraction modes. Mass spectrum dependence on flow rate and angular orientation agree qualitatively well with …

Enhanced Quantum Dots Spontaneous Emission With Metamaterial Perfect Absorbers, Wei Wang, Xiaodong Yang, Ting S. Luk, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metamaterial perfect absorbers (PAs) made of a hexagonal array of holes on Ag-SiO 2 -Ag thin films have been realized and utilized to enhance the spontaneous emission rate and photoluminescence intensity of CdSe/ZnS quantum dots (QDs) spin-coated on the absorber top surface. Perfect absorption of incoming light occurs at the wavelength where the impedance is matched to that of the free space. When QDs strongly excite both the electric and magnetic resonances at this perfect absorption wavelength, a significant Purcell effect on the spontaneous emission process and enhanced radiative outcoupling of photoluminescence intensity are expected. For perfect absorbers with near-unity …

Fabrication Of Alcocrfeni High-Entropy Alloy Coating On An Aisi 304 Substrate Via A Cofe₂Ni Intermediate Layer, Wenyuan Cui, Sreekar Karnati, Xinchang Zhang, Elizabeth Burns, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Through laser metal deposition, attempts were made to coat AlCoCrFeNi, a high-entropy alloy (HEA), on an AISI 304 stainless steel substrate to integrate their properties. However, the direct coating of the AlCoCrFeNi HEA on the AISI 304 substrate was found to be unviable due to cracks at the interface between these two materials. The difference in compositional change was suspected to be the source of the cracks. Therefore, a new transition route was performed by coating an intermediate layer of CoFe₂Ni on the AISI 304 substrate. Investigations into the microstructure, phase composition, elemental composition and Vickers hardness were …

Active-Passive Dynamic Consensus Filters: Theory And Applications, John Daniel Peterson

Doctoral Dissertations

”This dissertation presents a new method for distributively sensing dynamic environments utilizing integral action based system theoretic distributed information fusion methods. Specifically, the main contribution is a new class of dynamic consensus filters, termed active-passive dynamic consensus filters, in which agents are considered to be active, if they are able to sense an exogenous quantity of interest and are considered to be passive, otherwise, where the objective is to drive the states of all agents to the convex hull spanned by the exogenous inputs sensed by active agents. Additionally, we generalize these results to allow agents to locally …

Build Strategy Investigation Of Ti-6al-4v Produced Via A Hybrid Additive Manufacturing Process, Lei Yan

Doctoral Dissertations

“Till now, laser metal deposition (LMD) has been developed with the capability of near-net shape high-performance metal parts fabrication, especially complicated titanium alloys, nickel alloys, and aluminum alloys. However, LMD processed parts usually do not meet end-use requirements without post treatments. In-process part quality inspection and inner features machining are impossible within a single LMD process. Hybrid additive manufacturing (HAM), which integrates additive and subtractive manufacturing in one process, has been proposed to increase the feasibility of complex parts fabrication. This dissertation aims to improve the applications of Ti-6Al-4V parts fabricated via a HAM technique. The first research topic is …

Light Touch Based Virtual Cane For Balance Assistance During Standing, Sindhu Reddy Alluri

Masters Theses

"Can additional information about one's body kinematics provided through hands improve human balance? Light-Touch (LT) through hands helps improve balance in a wide range of populations, both healthy and impaired. The force is too small to provide any meaningful mechanical assistance -- rather, it is suggested that the additional sensory information through hands helps the body improve balance.

To investigate the potential for improving human balance through biofeedback through hands, we developed a Virtual Cane (VC) for balance assistance during standing. The VC mimics the physical cane's function of providing information about one's body in space. Balance experiments on 10 …

Characterization Of The Surface Condition In Aa6061 Resulting From Deep Rolling As A Function Of Common Industrial Parameters, Andrew Kenneth Layer

Masters Theses

"Roller burnishing is widely used in industry to improve the surface finish and fatigue life of components. As weight reduction continues to grow in the automotive and transportation industries, deep rolling can help maintain product performance by mitigating the increase in component stresses resulting from lower weight systems. Deep rolling parameters such as tool, applied angle, feed rate, spindle speeds, and relative tool direction all affect cycle time, product performance, and appearance. The effects of common industrial parameters on the resultant surface roughness and residual stress profiles were studied in this investigation. The samples were manufactured on a CNC lathe …

The Effect Of Cell Size And Surface Roughness On The Compressive Properties Of Abs Lattice Structures Fabricated By Fused Deposition Modeling, Leah Hope Mason

Masters Theses

"Postprocessing is an important step in many manufacturing methods, but it is especially important for additive manufacturing. Researchers looking to improve the surface roughness of acrylonitrile butadiene styrene (ABS) parts fabricated by fused deposition modeling (FDM) have determined that acetone smoothing not only achieves improved surface roughness but increases compressive strength as well. This could be very beneficial to lattice structures, which are known for already having an excellent strength to weight ratio. If the compressive strength of ABS lattice structures could be improved even further using acetone smoothing, it could expand the applications for plastic lattice structures and improve …

Multiphysics Prediction Model Of Microwave Curing For Thick Polymer Composites, Siva Dasari

Masters Theses

"Microwave curing technologies have many advantages over the traditional thermal curing methods for the manufacturing of fiber reinforced polymers, especially the processing speed and energy efficiency. Energy can be instantaneously transferred through applied electromagnetic fields and heat is generated based on dipolar rotational interactions. Microwave curing processes have been used for glass fiber composites but there are significant challenges associated with microwave curing of carbon fiber composites. Efficient heating may be difficult due to high dielectric loss associated with carbon fibers. Laminate quality will be highly dependent on the uniformity of the electromagnetic field in the material. In this work, …