Aerospace Engineering Commons^™

Enhancing High Cycle Fatigue Perfomance Of Electron Beam Melted Ti6al4v: A Study On Shot Peening And Hot Isostatic Pressing, Naghmeh M. Mojib, Dwayne D. Arola, Ramulu Mamidala

15th International Conference on Shot Peening

The qualification of electron beam powder bed fusion (PBF-EB) for safety-critical applications is hindered by variability in high cycle fatigue performance, largely due to surface roughness and internal defects. While Hot Isostatic Pressing (HIP) effectively reduces internal porosity, it does not address surface-initiated fatigue failures. This study investigated the combined effects of HIP and shot peening on enhancing the fatigue performance of PBF-EB Ti6Al4V. Over 50 specimens, including both vertical and horizontal build orientations, underwent high cycle fatigue testing per ASTM E466. X-Ray computed tomography confirmed decrease in defect distribution following HIP, while shot peening resulted in a more uniform …

Improvement Of The Fatigue Behaviour Of Additive Manufatured Scalmalloy By Using Surface Improvement Processes, Francisco José Boby Alcaide, Irene Eras, José Manuel De Los Santos, Alejandro Munoz Castro, Antonio Perinan Butrón, Jorge Sogorb

15th International Conference on Shot Peening

The use of light metals such as Aluminum alloys has experienced a remarkable increase for the additive manufacturing (AM) industry, especially in aerospace.

AM Scalmalloy®. (an Al-Mg-Sc alloy) shows outstanding behavior with much higher mechanical performance with respect to other alloys for powder bed fusion laser-based (PBF-LB) process like AlSi10Mg or AlSi7Mg. Recent studies have mainly focused on static loading, with minor attention to cyclic loading despite its vital importance in many applications.

In this work, the fatigue performance of PBF-LB Scalmalloy was investigated considering the effects of surface treatments to identify the set of optimal post-processes. Shot peening with …

Methodologies And Applications Of Precision Shot Peening To Hole Or Slot Geometry, James C. Hoffman

15th International Conference on Shot Peening

Shot peening, a commonly used method of fatigue and surface enhancement, is a critical process in many of the components in the aerospace industry. When it comes to small holes and/or slot geometries in these components, the process can become a challenge when these features are smaller than a conventional size Almen strip. In these cases, a decision must be made about how to process this type of geometry. Oftentimes, the method to apply the shot peen process is already defined in a process specification or part print so we must adhere to that method. If a method is not …

The E-Strip® As A Tool For Predictive Maintenance To Monitor And Control Shot Peening Processes, Walter A. Beach, Scott Glasier

15th International Conference on Shot Peening

The primary objective of this paper is to demonstrate the E-Strip® is capable of providing real-time feedback to the machine controller for making necessary process adjustments due to external forces, such as machine wear. Adjustments may include regulating air pressure and shot flow within pre-defined tolerances dictated by specification. It is anticipated that this integrated approach will significantly reduce variations in intensity levels observed from part to part and lot to lot.

Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy

15th International Conference on Shot Peening

The deep penetration of laser peening (LP) and retention of residual stress at high temperature by LP is significant in improving fatigue life and strength of superalloys exposed to high temperature and corrosion. Single crystal CMSX-4, was evaluated for stress relaxation and both fatigue life and fatigue strength of material that was LP-treated compared to non-LP and shot-peened (SP) specimens. LP was done with multiple layers using a 20 J/pulse laser where the laser high energy enabled using a 5 mm spot size on the metal surface. Stress measurements by the slitting technique showed the plastic penetration depth exceeded SP …

Overcoming Variable Illumination In Photovoltaic Snow Monitoring: A Real-Time Robust Drone-Based Deep Learning Approach, Amna Mazen, Ashraf Saleem, Kamyab Yazdipaz, Ana Dyreson

Michigan Tech Publications

Snow accumulation on photovoltaic (PV) panels can cause significant energy losses in cold climates. While drone-based monitoring offers a scalable solution, real-world challenges like varying illumination can hinder accurate snow detection. We previously developed a YOLO-based drone system for snow coverage detection using a Fixed Thresholding segmentation method to discriminate snow from the solar panel; however, it struggled in challenging lighting conditions. This work addresses those limitations by presenting a reliable drone-based system to accurately estimate the Snow Coverage Percentage (SCP) over PV panels. The system combines a lightweight YOLOv11n-seg deep learning model for panel detection with an adaptive image …

Performance Of A Two-Body Wave Energy Converter With An Annular Heave Plate, Raj Tamakuwala, Muhammad Usman, Nathan Tom, Hassan Masoud

Michigan Tech Publications

We theoretically examine the performance of a two-body wave energy converter (WEC) featuring a floating sphere and a submerged annular heave plate, connected by a power take-off (PTO) system. Utilising linear wave theory, we derive the system's frequency-domain response to regular plane waves and analyse the impact of varying disk porosity on power generation. Our results suggest that annular disks can enhance power extraction efficiency in various cases compared with solid heave plates. Additionally, permeable plates can broaden operational conditions by reducing oscillation amplitudes and decreasing the mechanical strain on the PTO system without substantially compromising the power conversion efficiency. …

Cryogenic Gas Cell For Infrared Space Instrumentation, Trent Newswander, Scott Bailey, Mark Hervig, Phillip Scott, Ryan Luder, Mike Watson, Mike Oksness, Cody Secrist, Zack Hatfield

Space Dynamics Laboratory Publications

The Doppler Wind and Temperature Sounder (DWTS) is being developed for flight on NASA’s Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC) satellite. DWTS will view the Earth limb orthogonal to the spacecraft ram and uses gas-filter correlation radiometry to detect the Doppler shift of atmospheric emission. The observations yield horizontal winds and kinetic temperature with high precision, excellent spatial resolution, and altitude coverage from 40–250 km. DWTS detects Doppler shifting of NO and 13CO2 atmospheric emission lines by passing the incident light through an onboard cell containing both gases that is cooled to near cryogenic temperatures. This work describes the DWTS instrument, …

Occulation Observations With Event-Based Vision Sensors [ Poster ], Rachel Oliver, Paul Rickerhauser, Brian Mcreynolds

Faculty Publications

Event-based vision sensors (EVS) offer exceptional change detection capabilities due to their asynchronous and independent pixels which record binary events with changes in their photocurrent. The resulting address event representation data is a sparse timeseries list.

A Feasibility Study Into The Usability And Application Of An Unmanned Aerial Vehicle For Aircraft Inspection And Quality Assurance Inspections, Reece P. Bhave

Journal of Aviation Technology and Engineering

The global aviation industry is often characterized as one of the safest modes of transportation in the modern world. With an abundance of quality assurance inspections and checks to determine operations safety, modern-day commercial aircraft that are utilized for passenger and cargo flights are held to a higher safety standard defined by regulatory bodies, such as the Federal Aviation Administration in the United States of America and the European Union Aviation Safety Agency in the European Union. While these quality standards are maintained via a series of inspections, checks, and preventative maintenance procedures, they are limited to only visual or …

Self-Organization In Metal Plasticity: An Ilg Update †, Avraam Konstantinidis, Konstantinos Spiliotis, Amit Chattopadhyay, Elais C. Aifantis

Michigan Tech Publications

In a 1987 article of the last author dedicated to the memory of a pioneer of classical plasticity Aris Philips of Yale, the last author outlined three examples of self-organization during plastic deformation in metals: persistent slip bands (PSBs), shear bands (SBs) and Portevin Le Chatelier (PLC) bands. All three have been observed and analyzed experimentally for a long time, but there was no theory to capture their spatial characteristics and evolution in the process of deformation. By introducing the Laplacian of dislocation density and strain in the standard constitutive equations used for these phenomena, corresponding mathematical models and nonlinear …

Energy-Aware Optimal Reconfiguration Of A Heterogeneous Connected And Automated Vehicle Cohort On A Limited-Access Highway, Pruthwiraj Santhosh, Darrell Robinette, Daniel Knopp, Jeffrey Naber, Jungyun Bae

Michigan Tech Publications

This paper presents an optimized vehicular reordering methodology designed to minimize energy consumption within heterogeneous cohorts operating at constant velocity on limited-access highways. The approach addresses the challenge of optimizing vehicle sequencing by considering both aerodynamic drag reduction benefits and the energy costs of reconfiguring a cohort from a stochastic initial state. This study provides empirical validation through on-road vehicle tests, demonstrating significant energy savings, achieving up to 10% reduction in axle energy for optimally configured cohorts compared to independent operation. A System of Systems (SoS) simulation environment, integrating micro-traffic, validated powertrain, and aerodynamic drag reduction models, was developed to …

Terra Lunaris: Assessment Of A Lunar Habitat For Scientific Astronauts, Space Miners, Or Space Tourists, Dirk Schumann, Robert A. Goehlich

Publications

This conceptual paper explores ground- based habitable space modules for various applications. The Terra Lunaris concept serves as the baseline and is evaluated in comparison to existing and theoretical studies in this field. Terra Lunaris is a compact hybrid habitat that expands to offer nearly four times its transport volume by combining rigid modules with an inflatable shell. With most interior elements pre-installed and foldable, setup time and complexity are minimized. The design integrates technical zones, living quarters, and shared spaces, while also supporting psychological well-being under extreme conditions. The paper provides both qualitative and quantitative analyses of lunar habitation …

Nitric Oxide Radiometer Development, Deron Scott, Phil Scott, Trent Newswander, Marty Mlynczak

Space Dynamics Laboratory Publications

SDL developed a small satellite payload to support the NICEcube mission concept capable of measuring vertical profiles of infrared radiance at 5.3 µm from nitric oxide (NO) in the atmospheric limb (100-250 km). These radiance measurements can be directly inverted to achieve vertical profiles of infrared cooling rates which are crucial to understanding the density response to the thermosphere in times of elevated geomagnetic activity. The payload was designed to fit on a 12U cube sat, function at low power and small mechanical envelope. Completed work includes building the telescope, integrating a representative detector, alignment, test planning, and initial testing. …

A Polar Turbulence Invariant Map With Applicability To Realisable Machine Learning Turbulence Models, James G. Wnek, Christopher Schrock, Eric M. Wolf, Mitch Wolff

Mechanical and Materials Engineering Faculty Publications

Invariant maps are a useful tool for turbulence modelling, and the rapid growth of machine learning-based turbulence modelling research has led to renewed interest in them. They allow different turbulent states to be visualised in an interpretable manner and provide a mathematical framework to analyse or enforce realisability. Current invariant maps, however, are limited in machine learning models by the need for costly coordinate transformations and eigendecomposition at each point in the flow field. This paper introduces a new polar invariant map based on an angle that parametrises the relationship of the principal anisotropic stresses, and a scalar that describes …

A Test Rig For An Aircraft Propeller Powered By Battery Motor, C. M. Vigneswaran, J. Induja, K. S. Bharath, M. J. Spoorthi, R. Chethana

Journal of Aviation Technology and Engineering

The propeller test rig is a crucial component in aeronautical engineering that plays a vital role in the development, testing, and optimization of propeller systems for aircraft. This research outlines the design, development, and performance evaluation of a state-of- the- art propeller test rig developed for research and testing purposes. The primary objective of this project is to enhance the understanding of propeller dynamics and efficiency, leading to the improvement of aircraft propulsion systems. The test rig provides a controlled environment to evaluate and compare multiple propeller designs, aiding engineers in making informed decisions during the design process. An advanced …

A Framework For Test Planning Of A Vision System Supporting Aerial Refueling, Jonathon K. Parry, Donald H. Costello, Michael D. M. Kutzer, Charles J. Doherty, Sarah M. Hubbard

Journal of Aviation Technology and Engineering

This essay presents a framework for evaluating a computer vision system providing perception for an uncrewed aircraft completing the automated air-to-air refueling (A3R) task. As the Department of Defense acquires capabilities that exhibit increasing levels of autonomy, the test and evaluation community must adapt the current framework to provide airworthiness officials the information required to accurately access the risks associated with the system underdoing testing. Following a brief introduction to A3R, this essay lays out a testing framework that leverages dendritic analysis and effectively deconstructs the critical issue into measurable data elements that can be used to support test and …

Event-Based Sensor Noise Modeling For Space-Based Space Domain Awareness, Rachel Oliver, Brian Mcreynolds, Dmitry Savransky

Faculty Publications

Building off the foundation of a physics-based end-to-end model for event-based vision sensors (EVS) observing resident space objects (RSOs), we apply new techniques to model realistic low-light sensor noise. While previous approaches simulate memorized current leakage and apply temporal noise models, our methods improve on these approaches and additionally account for current-following noise as an event source. These improvements are key components for accurate event-generating simulators which can advise requirements and concepts of operations for dedicated event-based Space Domain Awareness (SDA) architectures. The EVS pixel’s independent and asynchronous recording of changes in photocurrent produces data with high temporal resolution and …

The Atmospheric Waves Experiment (Awe), L. Scherliess, M. J. Taylor, P.-Dominique Pautet, Y. Zhao, B. Lamborn, H. Latvakoski, G. Cantwell, P. Sevilla, E. Syrstad, J. Forbes, S. Eckermann, D. Fritts, D. Janches, H. Liu, J. Snively

Space Dynamics Laboratory Publications

Modern theory and modeling indicate that atmospheric gravity waves (AGWs) play an important role in vertical coupling of the atmosphere-ionosphere system. Although small-scale AGWs (horizontal wavelengths ~30–300 km) are thought to account for the dominant energy and momentum inputs at Ionosphere-Thermosphere-Mesosphere (ITM) altitudes, the sources, variability, and influences of small-scale AGWs are still major unknowns. NASA’s Atmospheric Waves Experiment (AWE) mission is a Heliophysics Small Explorers Mission of Opportunity designed to investigate how terrestrial weather affects space weather, via small-scale AGWs produced in Earth’s atmosphere. Installed on the International Space Station (ISS) in November 2023, AWE began its 2-year mission …

Electrical Characterization Of Germanium Tin Alloys And Devices For Space Reliability, Kevin K. Choe

Theses and Dissertations

GeSn (germanium tin) alloys are potentially well suited for near-mid infrared space optoelectronic applications. Alloys of GeSn have similar properties to group III-V and mercury-cadmium-telluride semiconductors and are compatible with cost-effective complementary metal oxide semiconductor (CMOS) manufacturing technology. Recent progress in non-equilibrium remote plasma-enhanced chemical vapor deposition (RPECVD) has enabled the crystalline growth of GeSn with Sn concentrations of up to 10% without Sn surface segregation. Several experimental studies in previous literature report CVD- or molecular beam epitaxy (MBE)-grown GeSn alloys achieving a direct bandgap with 6%-9% Sn content. This novel growth technique opens opportunities for a cost-effective, next-generation optical …