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Articles 301 - 330 of 3261
Full-Text Articles in Aerospace Engineering
Finite-Time Control Strategies For Rendezvous And Proximity Operations, John Tamotsu Akagi
Finite-Time Control Strategies For Rendezvous And Proximity Operations, John Tamotsu Akagi
All Graduate Theses and Dissertations, Fall 2023 to Present
One common metric to use when designing a controller is the time that the system will take to reach the desired state. Unfortunately, many approaches to developing controllers only guarantee that the system will approach, but not exactly reach, the desired state. This can become a limitation in time-sensitive situations where rapid and complete convergence is necessary. One group of control methods, known as finite-time control, does guarantee both faster convergence and that the desired state will be reached, but often fails to define exactly what time that will occur, how much control will be used to get there, and …
Improving Robustness Of Learning-Based Approaches In Autonomous Systems And Engineering Education, Godwyll Aikins
Improving Robustness Of Learning-Based Approaches In Autonomous Systems And Engineering Education, Godwyll Aikins
Theses and Dissertations
This dissertation advances the development of robust learning-based approaches across two complementary domains: engineering education and autonomous systems. Through four studies, this research addresses critical challenges in preparing data-proficient engineers and developing reliable autonomous systems that can operate under uncertainty and incomplete information. The engineering education study examines how mechanical and aerospace engineering undergraduates conceptualize and develop data proficiency skills essential for modern engineering practice. Through interviews with 27 students, the research employs the How People Learn framework to analyze student perspectives on information literacy, data interpretation, and computational thinking. The findings inform pedagogical strategies for developing data proficiency in …
Biaxial Strain Tuned Upconversion Photoluminescence Of Monolayer Ws2, Shrawan Roy, Xiaodong Yang, Jie Gao
Biaxial Strain Tuned Upconversion Photoluminescence Of Monolayer Ws2, Shrawan Roy, Xiaodong Yang, Jie Gao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Monolayer tungsten disulfide (1L-WS2) is a direct bandgap atomic-layered semiconductor material with strain tunable optical and optoelectronic properties among the monolayer transition metal dichalcogenides (1L-TMDs). Here, we demonstrate biaxial strain tuned up conversion photoluminescence (UPL) from exfoliated 1L-WS2 flakes transferred on a flexible polycarbonate cruciform substrate. When the biaxial strain applied to 1L-WS2 increases from 0 to 0.51%, it is observed that the UPL peak position is redshifted by up to 60 nm% strain, while the UPL intensity exhibits exponential growth with the up-conversion energy difference varying from − 303 to − 120 meV. The measured …
Uncovering Upconversion Photoluminescence In Layered Pbi2 Above Room Temperature, Sharad Ambardar, Xiaodong Yang, Jie Gao
Uncovering Upconversion Photoluminescence In Layered Pbi2 Above Room Temperature, Sharad Ambardar, Xiaodong Yang, Jie Gao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
As a van der Waals (vdW) layered semiconductor material, lead iodide (PbI2) possessing a direct bandgap with strong photoluminescence emission in visible range has gained wide attention in applications of photonic and optoelectronic devices. Here, up conversion photoluminescence (UPL) in exfoliated PbI2 flakes is demonstrated at room temperature and elevated temperatures. The linear power dependence of UPL emission with 532 nm excitation suggests the one-photon involved multiphonon-assisted UPL emission process, which is revealed by the temperature-dependent UPL emission measurement. Meanwhile, the nonlinear power dependence of UPL emission with 561 nm excitation indicates the transition of UPL emission mechanism from linear …
Quasi-Static Indentation Characteristics Of Foam-Filled Sandwich Composite Structures With Additively Manufactured Cfrp And Gfrp Corrugated Cores, S.Z.H. Shah, Juhyeong Lee, Khurram Altaf, M. Mohammad, M.Z. Hussain, R.S. Choudhry
Quasi-Static Indentation Characteristics Of Foam-Filled Sandwich Composite Structures With Additively Manufactured Cfrp And Gfrp Corrugated Cores, S.Z.H. Shah, Juhyeong Lee, Khurram Altaf, M. Mohammad, M.Z. Hussain, R.S. Choudhry
Mechanical and Aerospace Engineering Faculty Publications
This paper presents an experimental investigation on the quasi-static indentation performance of polyurethane (PU) foam-filled carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) corrugated sandwich composite structures (SCSs) under different indenter tip geometries (conical, trapezoidal, hemispherical, pyramidal, and cylindrical shapes). The SCSs were produced using hybrid manufacturing methods: (1) the facesheets were fabricated using the vacuum-assisted resin infusion (VARI) process, (2) the CFRP and GFRP corrugated cores were additively manufactured using the fused filament fabrication (FFF) process, and (3) the self-expanding PU foam-filled the open spaces in the core. The results elucidated that the indenter tip geometry and core …
Development And Testing Of A Fast-Acting, 8-Bit, Digital Throttle For Hybrid Rocket Motors, Stephen A. Whitmore
Development And Testing Of A Fast-Acting, 8-Bit, Digital Throttle For Hybrid Rocket Motors, Stephen A. Whitmore
Mechanical and Aerospace Engineering Faculty Publications
The potential for throttle control of hybrid rocket systems has long been known as a potential advantage for a variety of applications. Because only a single flow path is controlled, theoretically, hybrids should be significantly easier to throttle than bipropellant systems. Unfortunately, the slow response times and nonlinearity of traditional position-control valves have limited practical applications of hybrid throttling. This paper presents an alternative throttling system where the oxidizer flow path is broken into multiple streams, with each flow path controlled by a solenoid-operated on/off valve. The parallel paths allow significantly faster and more precise control than can be achieved …
Multiscale Analysis Of Thermal Barrier Coated Cfrp Composites Under Thermal Loading, Devin Nielsen, Trenton M. Ricks, Juhyeong Lee
Multiscale Analysis Of Thermal Barrier Coated Cfrp Composites Under Thermal Loading, Devin Nielsen, Trenton M. Ricks, Juhyeong Lee
Mechanical and Aerospace Engineering Student Publications and Presentations
Carbon-fiber reinforced polymer (CFRP) composites are commonly used in high performance applications. Although offering several advantages (i.e., superior specific properties and improved structural rigidity), traditional CFRP composites often exhibit poor thermal stability due to a low matrix thermal decomposition temperature. The effective operating temperature of the CFRP composites can be raised by applying an outermost, protective thermal barrier coating (TBC) layer. Prefabricated high void content ceramic TBCs are ideal for composite applications due to their high thermal stability and relatively low thermal conductivity. In this paper, the thermo-mechanical response of the TBCCFRP composite laminate subjected to 500°C are assessed through …
Numerical Study Of Flow Control On An Asymmetric Beveled Trailing Edge, M. M. Mosallem, Zienab A. Ahmed
Numerical Study Of Flow Control On An Asymmetric Beveled Trailing Edge, M. M. Mosallem, Zienab A. Ahmed
Journal of Engineering Research
The current research aims to numerically study the effect of inserting a small rod into the wake of an asymmetric beveled trailing edge on the hydrodynamic forces and wake structure. The test model used in this study is a blunt-faced flat plate of thickness H and having an asymmetrical 60° beveled trailing edge. A control rod with diameter d = 0.2 H was inserted into two different locations (Location (1); x/H = 0.18, y/H = 1.0) and (Location (2); x/H = 0.28, y/H = 0.9) behind the trailing edge. Unsteady 2D numerical simulation was performed at Reynolds number, …
Editorial For The Special Issue On Nanomaterials For Micro/Nanodevices, Amir Hussain Idrisi
Editorial For The Special Issue On Nanomaterials For Micro/Nanodevices, Amir Hussain Idrisi
Michigan Tech Publications
The Special Issue of Micromachines, titled "Nanomaterials for Micro/Nanodevices", comprehensively examines the intersection of nanotechnology and micro/nanodevices [...].
Study Of The Synthesis Mechanism And Some Properties Of Oligomers Based On Epichlorohydrin And Diphenylguanidine, Rovshan Israilovich Ismailov, Normuhamad Edgarov, Alisher Israilovich Ismailov
Study Of The Synthesis Mechanism And Some Properties Of Oligomers Based On Epichlorohydrin And Diphenylguanidine, Rovshan Israilovich Ismailov, Normuhamad Edgarov, Alisher Israilovich Ismailov
Technical science and innovation
In this work, the synthesis and the scheme for obtaining an oligomer based on epiiodhydrin with diphenylguanidine were studied, the proportions of epiiodhydrin in the initial mixture, the yield of oligomers, and the reduced viscosity were studied. The results of spectroscopic and elemental analyzes are obtained, which show that changes in the ratio of monomers have almost no effect on the iodine content in the oligomer. This is apparently due to the fact that epiiodhydrin is much more active in reactions than amino compounds. By studying the degree of conversion on the viscosity of the oligomerization products, the effects on …
Study Of The Physical-Chemical Properties Of Chitosan Synthesized By The Cryogenic Method From Apis Mellifera Bees, Dilnoza Sohibovna Isomitdinova, Gulnora Akmalovna Ikhtiyarova, Jahongir Mustaqim O’G’Li Sharopov
Study Of The Physical-Chemical Properties Of Chitosan Synthesized By The Cryogenic Method From Apis Mellifera Bees, Dilnoza Sohibovna Isomitdinova, Gulnora Akmalovna Ikhtiyarova, Jahongir Mustaqim O’G’Li Sharopov
Technical science and innovation
Chitosan was synthesized from Apis Mellifera dead bees by traditional and cryogenic methods, and the degree of deacetylation, viscosity, and molecular mass of the synthesized sample was studied. Chitosan was synthesized by deacetylation of chitin under cryogenic conditions. NaOH concentration 40%, temperature 90 ± 3 °C, time 120 min. The degree of deacetylation, and molecular mass was determined using an Ubbelode viscometer. DDA was determined by conductometric titration under standard conditions. The degree of deacetylation of Apis Mellifera chitosan was 87%. synthesized by cryogenic method DDA of chitosan was 83% synthesized by traditional method. Conducting the synthesis in liquid nitrogen …
Justification Of The Effectiveness Of Software For The Design Of Open-Pit Mining, Tolib Olimovich Komilov, Bobirjon Nabijonovich Ashurov, Ulugbek Bakhtiyorovich Sattarov, Ma’Ruf Ixtiyorovich Karimov
Justification Of The Effectiveness Of Software For The Design Of Open-Pit Mining, Tolib Olimovich Komilov, Bobirjon Nabijonovich Ashurov, Ulugbek Bakhtiyorovich Sattarov, Ma’Ruf Ixtiyorovich Karimov
Technical science and innovation
The article notes that the economic feasibility of implementing a project based on deposits directly affects the economy of the country and the region, as well as the construction of new facilities, the use of the most balanced approaches and design solutions in a complex will allow achieving the set goal of increasing production volumes and bringing the enterprise to a new level of development. In order to achieve the above goals, it has been proven with the implementation of investment projects using software for the design of open-pit mining, it is possible to further develop the region, agriculture with …
Development Of A Universal Humidity Converter At Ultra High Frequency, Hulkar Asadullayevna Usmonova, Asadulla Turgunbayev
Development Of A Universal Humidity Converter At Ultra High Frequency, Hulkar Asadullayevna Usmonova, Asadulla Turgunbayev
Technical science and innovation
The article proposes the and principle of operation of a universal primary measuring transducer of humidity at an ultra-high frequency with reciprocating motion along the vertical axis of rotation, which allows increasing the information redundancy of the primary measuring transducer (the influence of inhomogeneities, including humidity in the composition of the material, on the measurement result is averaged). The design of the primary measuring transducer under consideration provides for correction of the moisture measurement result by the mass (density) of the material, which will make it possible to carry out measurements without preliminary weighing the sample. The obtained results of …
Advancements In The Programmable Hyperspectral Seawater Scanner Measurement Technology For Enhanced Detection Of Harmful Algal Blooms, John J. Langan, Jungyun Bae
Advancements In The Programmable Hyperspectral Seawater Scanner Measurement Technology For Enhanced Detection Of Harmful Algal Blooms, John J. Langan, Jungyun Bae
Michigan Tech Publications
The Programmable Hyperspectral Seawater Scanner (PHySS) represents a significant breakthrough in monitoring harmful algal blooms (HABs), specifically targeting the “Florida red tide” caused by Karenia brevis. By utilizing a Fourth-Derivative Spectral Similarity Index (SI), this study establishes a strong positive correlation between the SI and phytoplankton counts, underscoring the PHySS’s potential for early detection and effective management of HABs. Our findings suggest that the PHySS could act as a predictive tool, offering crucial lead time to mitigate the ecological and economic repercussions of blooms. However, this study also identifies certain limitations of the PHySS technology, such as its inability to …
Cryogenic Fuel Applications To Sustainable Commercial Aircraft, Jack R. Kisling, Lillian Panning
Cryogenic Fuel Applications To Sustainable Commercial Aircraft, Jack R. Kisling, Lillian Panning
College of Engineering Summer Undergraduate Research Program
Finding a source of clean and renewable energy is one of the greatest challenges humanity will face in the 21st century. With populations expanding, developing countries increasing their use of resources, and the rapid and alarming effects of climate change, a shift to a sustainable future is an existential prospect.
The goal of our project is to take the first steps toward getting safety procedures and lab space established, so mechanical engineering senior projects can quickly begin to experiment with cryogenic fuels. They will explore the application of cryogenic fuels to commercial aviation.
Kinetic Modeling Of Dust Grain Dynamics In Electrostatic Sieving, Aaron Berkhoff, Easton Ingram, Fateme Rezaei, Jeffrey Smith, David Bayless, William Schonberg, Daoru Han
Kinetic Modeling Of Dust Grain Dynamics In Electrostatic Sieving, Aaron Berkhoff, Easton Ingram, Fateme Rezaei, Jeffrey Smith, David Bayless, William Schonberg, Daoru Han
Chemical and Biochemical Engineering Faculty Research & Creative Works
A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith dust 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. a case study for a concept of electrostatic sieving was chosen to validate the new model. the simulation achieved similar performance of particle size classification as reported in the literature. the new model is computationally efficient (takes a few minutes on a PC-type laptop computer) so …
Impact-Free Gaits For Planar Bipeds: Changing Walking Speed And Gait, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee
Impact-Free Gaits For Planar Bipeds: Changing Walking Speed And Gait, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The problems of changing the walking speed and stride length of impact-free gaits for point-foot planar bipeds are addressed. The impact-free gaits are designed using an approach developed in prior work. It is shown that the impulse controlled Poincaré map (ICPM) approach can be modified to transition between orbits defining gaits with different walking speeds, and the continuous controller can be changed during the swing phase to transition between gaits that have distinct stride lengths. The effectiveness of the approaches is demonstrated using simulations carried out on a five-link biped.
Iterative Correction Of Robotic Grinding Using Spatial Feedback For Precision Applications, Philip A. Olubodun, Joseph D. Fischer, Douglas A. Bristow
Iterative Correction Of Robotic Grinding Using Spatial Feedback For Precision Applications, Philip A. Olubodun, Joseph D. Fischer, Douglas A. Bristow
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Since the advent of robots, many tasks that were originally performed by humans have now been tasked to industrial robots. From a manufacturing standpoint, robots have primarily been used in pick-and-place or other non-machining operations that require high repeatability. However, with the increasing availability of CAD/CAM software and the development of high-precision metrology, comes the opportunity to integrate robots into a wider variety of manufacturing processes through the use of feedback control. One such machining operation that is being explored is precision grinding of metal parts. Most other work in this area has focused on force regulation to improve grind …
A Feedforward Kinematic Error Controller With An Angular Positioning Deviations Model For Backlash Compensation Of Industrial Robots, Mitchell R. Woodside, Tian Hao Cui, John Emelko, Soichi Ibaraki, Robert G. Landers, Douglas A. Bristow
A Feedforward Kinematic Error Controller With An Angular Positioning Deviations Model For Backlash Compensation Of Industrial Robots, Mitchell R. Woodside, Tian Hao Cui, John Emelko, Soichi Ibaraki, Robert G. Landers, Douglas A. Bristow
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The accuracy of industrial robots, typically on the order of several millimeters, has inhibited their adoption in advanced aerospace manufacturing applications, such as robotic machining. For this reason, extensive investigations have been conducted to develop solutions to improve their accuracy. These solutions can be categorized into offline and online compensation strategies, both of which have advantages and limitations. Offline compensation has been shown to improve the accuracy of industrial robots by two to three orders of magnitude; however, the sensitivity of these solutions to environmental changes and external disturbances can degrade their performance. In contrast, online compensation, which utilizes real-time …
Wind Shear Induced Tornados With Full Thermodynamic Effects, Kakkattukuzhy M. Isaac
Wind Shear Induced Tornados With Full Thermodynamic Effects, Kakkattukuzhy M. Isaac
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Wind shear-induced Tornado behavior under full thermodynamic formulation using the ideal gas equation is investigated. The computational fluid dynamics model that includes the energy equation is used to obtain solutions of a natural-scale tornado under pressure and temperature boundary conditions that account for their variations vs. altitude in the atmosphere. The present results show significant differences from previous isothermal simulations and those using the Boussinesq model for buoyancy under small temperature differences. Results show that the downdraft observed in tornados originating from supercells, often accompanied by rain and hail can be captured using the present model that simulates the genesis, …
Boosting Predictive Accuracy Of Single Particle Models For Lithium-Ion Batteries Using Machine Learning, Emmanuel Olugbade, Jonghyun Park
Boosting Predictive Accuracy Of Single Particle Models For Lithium-Ion Batteries Using Machine Learning, Emmanuel Olugbade, Jonghyun Park
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The accuracy of single particle (SP) models for lithium-ion batteries at high C-rates is constrained by lithium concentration gradients in the electrolyte, which affect ionic conductivity, overpotential, and reaction rates. This study addresses these limitations using extreme gradient boosting machine learning (ML). By training our ML model with data from a comprehensive electrochemical (P2D) model and performing sensitivity analysis on key battery parameters, we enhance predictive accuracy. Compared to conventional SP and P2D models under constant current loading, our ML-based SP model achieves similar predictive accuracy to P2D, with significant improvements in computational efficiency. Additionally, the ML-based SP model demonstrates …
Redwater Test Data, Paul Van Susante, Kris Zacny
Redwater Test Data, Paul Van Susante, Kris Zacny
Michigan Tech Research Data
The RedWater mission is to extract water from subterranean glaciers found on Mars. Honeybee robotics has contracted the PSTDL to conduct small scale tests in order to collect data on the power consumed by a high-density cartridge heater to melt through cryogenic clear ice at Martian atmospheric pressure.
Experimental Study Of Drag Characteristics And Dust Removal Performance Of A Hybrid Wet-Filter Precipitator, Hang Yi, Zifeng Yang, Deqiang Chang, Xinjiao Tian, Jingxian Liu
Experimental Study Of Drag Characteristics And Dust Removal Performance Of A Hybrid Wet-Filter Precipitator, Hang Yi, Zifeng Yang, Deqiang Chang, Xinjiao Tian, Jingxian Liu
Mechanical and Materials Engineering Faculty Publications
With their advantages of high dust removal efficiency and low drag characteristics, hybrid wet-filter precipitators have great potential for dust control in coal mines, but the underlying mechanisms are not well understood. In this study, to help fill this knowledge gap, a hybrid wet-filter precipitator consisting of a 40-layer metal filter and a defogger device is designed and a prototype is constructed. Experiments are conducted to investigate its drag characteristics under wind velocities from 0.85 to 5.68 m/s and its dust removal performance under wind velocities of 2 and 4 m/s. On the basis of results with the initial design, …
Surrogate-Based Multidisciplinary Optimization For The Takeoff Trajectory Design Of Electric Drones, Samuel Sisk, Xiaosong Du
Surrogate-Based Multidisciplinary Optimization For The Takeoff Trajectory Design Of Electric Drones, Samuel Sisk, Xiaosong Du
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Electric vertical takeoff and landing (eVTOL) aircraft attract attention due to their unique characteristics of reduced noise, moderate pollutant emission, and lowered operating cost. However, the benefits of electric vehicles, including eVTOL aircraft, are critically challenged by the energy density of batteries, which prohibit long-distance tasks and broader applications. Since the takeoff process of eVTOL aircraft demands excessive energy and couples multiple subsystems (such as aerodynamics and propulsion), multidisciplinary analysis and optimization (MDAO) become essential. Conventional MDAO, however, iteratively evaluates high-fidelity simulation models, making the whole process computationally intensive. Surrogates, in lieu of simulation models, empower efficient MDAO with the …
A Robust Recurrent Neural Networks-Based Surrogate Model For Thermal History And Melt Pool Characteristics In Directed Energy Deposition, Sung Heng Wu, Usman Tariq, Ranjit Joy, Muhammad Arif Mahmood, Asad Waqar Malik, Frank Liou
A Robust Recurrent Neural Networks-Based Surrogate Model For Thermal History And Melt Pool Characteristics In Directed Energy Deposition, Sung Heng Wu, Usman Tariq, Ranjit Joy, Muhammad Arif Mahmood, Asad Waqar Malik, Frank Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In directed energy deposition (DED), accurately controlling and predicting melt pool characteristics is essential for ensuring desired material qualities and geometric accuracies. This paper introduces a robust surrogate model based on recurrent neural network (RNN) architectures—Long Short-Term Memory (LSTM), Bidirectional LSTM (Bi-LSTM), and Gated Recurrent Unit (GRU). Leveraging a time series dataset from multi-physics simulations and a three-factor, three-level experimental design, the model accurately predicts melt pool peak temperatures, lengths, widths, and depths under varying conditions. RNN algorithms, particularly Bi-LSTM, demonstrate high predictive accuracy, with an R-square of 0.983 for melt pool peak temperatures. For melt pool geometry, the GRU-based …
Customized Agile Project Management For Scientific Computing: Addressing Challenges And Developing A Framework, Yashesh Sakharikar
Customized Agile Project Management For Scientific Computing: Addressing Challenges And Developing A Framework, Yashesh Sakharikar
Harrisburg University Dissertations and Theses
This paper presents a novel Agile framework tailored for scientific computing projects. Identifying gaps in existing methodologies, the research emphasizes the need for adaptable solutions in this dynamic field. The proposed framework, characterized by flexibility and stakeholder engagement, addresses specific challenges posed by scientific computing endeavors. Through a comprehensive literature review, the paper highlights the limitations of generic Agile practices and positions the proposed framework as a valuable contribution. The study motivates further exploration into specialized Agile approaches, promising enhanced efficiency and success in scientific computing projects.
Enhancing Crossflow Dynamics Through The Gas Injection From Multiple Cylinders, Sahrish B. Naqvi, Sadia Siddiqa, Maciej Matyka, Rama S. R. Gorla, Md. Mamum Molla
Enhancing Crossflow Dynamics Through The Gas Injection From Multiple Cylinders, Sahrish B. Naqvi, Sadia Siddiqa, Maciej Matyka, Rama S. R. Gorla, Md. Mamum Molla
Faculty Publications
We investigate unsteady, two-dimensional laminar fluid flow around cylinders, focusing on understanding the impact of injecting methane gas through two diametrically opposite arcs on the cylinder in the crossflow of the second fluid. This study encompasses applications in mixing and dispersion, which are crucial in various technological and natural processes. Our analysis addresses velocity field’s contribution to the spatiotemporal distribution of transported quantities. We observed that mixing induces a transition from laminar to turbulent flow. Depending on the injected-to-crossflow velocity ratios, the wake vortices downstream of cylinder arrays separate from or connect to the injected gas. This phenomenon significantly impacts …
Experimental And Computational Investigation Of Green Laser Propagation Through Turbulent Medium In A Water Tank, Richard Owusu Adansi
Experimental And Computational Investigation Of Green Laser Propagation Through Turbulent Medium In A Water Tank, Richard Owusu Adansi
Open Access Theses & Dissertations
Turbulence medium poses significant challenges to the propagation of laser beams, impacting applications such as free-space optical communication, remote sensing, and laser weapons systems. Therefore, comprehending and mitigating turbulence effects are vital for enhancing the performance of these systems. Analysis of a strong turbulence impact on electromagnetic wave propagation requires extensive knowledge of the Earth's atmospheric and Oceanic phenomena and Maxwell's electromagnetic theory of light as a propagating wave of electric and magnetic fields. Optical systems' propagation often encounters Strong Turbulence, causing interference and diffraction. Nonetheless, light propagation through randomly fluctuating media has been an exciting and active area of …
Trade-Offs In Lighting For Dic Strain Measurements In Vibration-Based Fatigue Testing, Jacob R. Rigby
Trade-Offs In Lighting For Dic Strain Measurements In Vibration-Based Fatigue Testing, Jacob R. Rigby
All Graduate Theses and Dissertations, Fall 2023 to Present
Vibration based fatigue testing offers a fast and efficient method for determining the breaking point of a material. This method often uses a device, called a strain gage, to measure the deformation of a test sample at a single spot on the test sample. However, these strain gages often break before testing is complete. To overcome this premature break, a laser vibrometer is often used to measure the amount of movement or the speed of the test sample throughout the vibration test. The deformation measured by the strain gage is compared against the amount of movement or velocity of the …
Heat Treatment Post-Processing For The Improved Mechanical Properties Of Scalmalloy® Processed Via Directed Energy Deposition, Rachel Boillat-Newport, Sriram Praneeth Isanaka, Frank Liou
Heat Treatment Post-Processing For The Improved Mechanical Properties Of Scalmalloy® Processed Via Directed Energy Deposition, Rachel Boillat-Newport, Sriram Praneeth Isanaka, Frank Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
As high-strength aluminum alloys present several processability issues with additive manufacturing (AM), Scalmalloy®, an Al-Mg-Sc-Zr-based alloy, has been developed. This alloy is age-hardenable, allowing it to precipitate out a strengthening precipitate phase, Al3(Sc,Zr). The manufacturer recommends a single-stage aging treatment at 325 °C for 4 h; however, the majority of the literature studies utilize a powder bed processing known as selective laser melting (SLM) over powder-fed processing directed energy deposition (DED). This study addresses the lack of information on heat treatments for DED fabrication by exploring the application of artificial aging temperatures of 300–400 °C for 2, 4, and 6 …