Mechanical Engineering Commons^™

Internal Resonance Of A T-Shaped Electrostatic Levitation Actuator, Ali Eskandari, Mohammad Alzgool, Yu Tian, Mohammad I. Younis, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This study explores the internal resonance of a T-shaped beam subjected to electrostatic forces at the MEMS scale. The actuator's unique configuration includes a side substrate, a fixed bottom substrate, and a suspended beam, enabling out-of-plane movement when excited. The T-shaped beam is designed to have a commensurate ratio of 1:2 between the fifth and sixth modes. The mathematical model of the system is developed and the shooting method is used to solve the reduced order model. Theoretical and experimental results reveal the interaction of two modes. The results indicate that due to the exchange of energy between the two …

Advances In Encapsulated Phase Change Materials For Integration In Thermal Management Applications, Muhammad Ghufran, David Huitink

Mechanical Engineering Faculty Publications and Presentations

Encapsulated phase change materials (ePCMs) have the potential to emerge as a key solution for efficient thermal management in various applications. This review paper explores the recent advancements in ePCMs for thermal energy storage and thermal management. We start with a basic overview of the PCMs and then performance enhancements of PCMs through the encapsulation, critical parameters for encapsulation, various encapsulation methods, and their evaluation are discussed. This review also discusses key properties and proposed figure of merit for ePCMs, impact of encapsulation on thermophysical properties, performance evaluation of ePCMs, thermal management needs, and the role of PCMs. The paper …

Multiphysics Modeling, Analysis, And Design Of Ceramic Hollow Fiber Membranes For Oxygen Separation, Hamed Abdolahimansoorkhani

Theses and Dissertations

Oxygen plays a central role in numerous industrial processes. Several technologies have been reported for producing oxygen from air. Among them, oxygen transport membrane (OTM) technology—based on mixed-conducting, gas-tight ceramic membranes—has attracted significant attention due to its high oxygen selectivity, relatively low capital and operating costs, and versatility for both ex-situ and in-situ applications. Mathematical modeling of OTMs offers a powerful tool to investigate internal multi-physics transport phenomena, providing deeper insight into fundamental mechanisms while serving as a cost-effective approach for optimizing membrane stack designs.

After a comprehensive introduction, in the first part of this dissertation (chapter 2), a comprehensive …

Recognizing The Unexpected: Deep Learning Across Complex Environments, Ge Song

Theses and Dissertations

Ensuring the security, trustworthiness, and operational integrity of modern autonomous and cyber-physical systems presents a critical challenge. While widely utilized in various engineering applications, such as intelligent transportation and industrial manufacturing, these systems require robust monitoring frameworks to identify unexpected anomalies in real-time, thereby maintaining operational safety and efficiency. This dissertation develops advanced deep learning methodologies for anomaly detection and health monitoring, with a particular emphasis on semisupervised reconstruction-based approaches that identify anomalies in complex environments using models trained only with normal operational patterns.

Building on this theme, the first study focuses on analyzing pedestrian behavior and detecting anomalies at …

Multi-Layer Decision Making For Long-Term Autonomous Mission Based On Dual Process Theory, Shruti Jadhav

Theses and Dissertations

Unmanned aerial vehicles (UAVs) are increasingly used in precision agriculture, where extended autonomous operation is required for monitoring, intervention, and field management. However, achieving long-term autonomy remains challenging due to battery constraints, environmental uncertainty, and the need to balance exploration with event-driven tasks. To address these challenges, a multi-layer decision-making framework inspired by Dual Process Theory (DPT) is developed. The framework combines reactive return-tobase strategies, exploratory navigation, and directional bias from prior missions, with a conflict-monitoring mechanism that adapts system behavior based on real-time conditions. The approach is implemented in a simulated agricultural grid environment, demonstrating improved adaptability and coverage …

Reduced Order Simulator Of A Nuclear Thermal Propulsion System, Jackson Taylor Zazzaro

Theses and Dissertations

This thesis presents the development of a reduced-order simulator for a nuclear thermal propulsion (NTP) system, designed to capture the key thermo-fluid and performance characteristics of such systems while maintaining computational efficiency. The primary objective of this work is to develop and demonstrate a modular simulation framework capable of modeling the coupled physics of an NTP reactor, nozzle, and orbital transfer system. The simulator integrates a reduced-order thermal-fluid model of the reactor, a simplified nozzle model, and an orbital transfer model, providing a comprehensive yet computationally efficient representation of the propulsion process. By employing reduced-order modeling techniques, the simulator achieves …

Rate-Dependent Interlaminar Shear Characterization In Solid-State Extruded Ultrahigh Molecular Weight Polyethylene Film Composites, Frank David Thomas Jr.

Theses and Dissertations

Ultrahigh Molecular Weight Polyethylene (UHMWPE) cross-ply [0o/90o] thin film composites are emerging as an effective material for impact applications due to their high axial strength-to-weight ratio and favorable delamination properties. Mode-II interlaminar shear (ILS) fracture-driven delamination has been shown to be a significant energy absorption mechanism. Therefore, accurately characterizing ILS behavior as a function of strain rate in these composites is essential to inform computational models. Since these composites are significantly thinner and weaker in both interlaminar shear and transverse tension than traditional carbon fiber epoxy composites, standard ILS Mode II test methods/specimens such as end-notched flexure (ENF) are expected …

Enhancing Two-Phase Heat Spreading: Development And Performance Evaluation Of Hermetically Sealed Hybrid Heat Sinks, Walker Ryan Champion

Theses and Dissertations

Modern, high-performance technology presents challenges for thermal management based on power density. To cool heat fluxes to this degree, conventional liquid-cooled heat sinks are utilized because air cooling becomes insufficient (>100 𝑊/𝑐𝑚² ). This study introduces a hybrid heat sink that integrates liquid cooling with a dropwise-enhanced vapor chamber, contains a hermetic seal, and achieves high thermal performance with low energy consumption. The temperature hotspots, thermal resistances, gravitational/pin effects, temperature uniformity, and coefficient of performance were investigated. Experimental results demonstrate a high cooling capacity of 600 W over a 6.25 𝑐𝑚² heating area with a low cooling …

Compost Grinder For The University Of South Carolina Office Of Sustainability, Rori E. Pumphrey, Grace Yaegel, Aaron R. Sawyer, Bradley White

Senior Theses

This project originates from a collaboration with the USC Office of Sustainability, which seeks to improve the handling and processing of food waste generated on campus. The primary challenge is the difficulty in composting certain types of food waste, such as avocado pits, pumpkin rinds, and other dense or fibrous organic materials that are not easily broken down using conventional methods. Existing commercial solutions are often too large and expensive, or electrically powered, and are thus not well suited for the volume or nature of USC's food waste. To address these limitations, our team designed a manually operated food waste …

Determination Of Tensile Strength Distribution Of Single Carbon Fibers At Microscale Gagelengths, Karan Deepak Shah

Theses and Dissertations

High performance carbon fibers are widely used as reinforcements in composite material systems for aerospace, automotive, and defense applications. The tensile strength of commercial fibers is significantly less than its theoretical limits. The composite systems are often overdesigned, thus any increase in the fiber tensile strength can yield significant cost and weight savings. Modification of fiber surface treatment (sizing) during manufacturing is a potential route to enhance fiber strength. Single fiber tensile testing at millimeter-scale is typically used to characterize the effect of sizing on the fiber strength. However, the longitudinal tensile failure of a composite system is a result …

Integration Of Sco2 Brayton Cycles With Carbon Capture Systems, Nathan C. Stearns, Rajarshi Roy, Brian Schooff, Andrew Chiodo, Andrew R. Fry, Brian D. Iverson

Faculty Publications

Increasing global energy consumption and greater market penetration of intermittent energy sources require a baseline power source to enable renewable energies. Here, a case is made for pairing supercritical CO₂ Brayton cycles with carbon capture to create low-emission, high-efficiency, combustion-based power generation systems. Pairing carbon capture and storage (CCS) systems with supercritical carbon dioxide (sCO₂) Brayton cycles enables the reduction of greenhouse gas emissions in combustion systems, but with an associated energy cost. Three different representative models of CCS systems (oxyfuel combustion, amine scrubbing, and cryogenic carbon capture) are considered for pairing with an sCO2 Brayton cycle, …

Mems 4110: Asme Waste Collection Challenge, Evelyn Madrigal, Letty Patino, Bing Ling, Michael Avaliani

Mechanical Engineering Design Project Class

Make a remote-controlled vehicle that can traverse the course below (obeying traffic laws), collect garbage units from collection bins and deliver the garbage units to a receptacle.

Mems 4110: N1 Precise Water Distribution System, Lillian Salter, Ye Huang, Elaine Wang, Joy Luo

Mechanical Engineering Design Project Class

The aim of the project is to construct a precise water distribution system for anthropology graduate student Christina Youngpeter, who is studying the impact of hydration levels on the growth of quinoa plants. As her experiment grows in scale, she increasingly needs a system that can measure and distribute water for her, saving hours otherwise spent meticulously measuring water for 36 plants and counting. The system must measure water accurately and distribute it to the plants cleanly and efficiently. It should also be scalable and autonomous, requiring minimal human intervention.

Mems 4110: Asme Waste Collection Challenge, Theo A. Mass, Grant Kaplan, Emanoeel Ghabrial, Joseph Gillett

Mechanical Engineering Design Project Class

The Efficient Jolley Trash Grabber (EJTG) is a teleoperated vehicle adherent to the modified rules of the 2025-26 ASME Student Design Competition, hosted in MEMS 4110: Mechanical Engineering Design Project. The vehicle design was informed first by understanding the problem of waste collection. Patents, existing devices, user needs, and relevant codes and standards were reviewed to survey potential design approaches. The concept for the vehicle was generated by setting functionality, and brainstorming solutions to accomplish each goal. A mock-up vehicle was created using available materials, and four complete concepts were drawn each with a different design. Rigorous methods were used …

Mems 4110: Conservation Of Angular Momentum Demo, Matthew Brouillet, Iyanu Akinyemi, Mingxuan Bi, Matthew Gimbel

Mechanical Engineering Design Project Class

A demo was built to serve as a hands-on experience for reinforcing concepts behind the conservation of angular momentum.

Mems 4110: Parachute Snatch Force Tester, Adam Mallalieu, Ethan Riak, Jackson Shurman, Ryan Schmadtke

Mechanical Engineering Design Project Class

This report discusses the design, development, and testing of a parachute snatch force tester for MEMS 411 Senior Design. The device is for the WURocketry Team, and aims to measure the peak force exerted on the rocket bulkhead during parachute ejection. This peak force is known as the snatch force, and is incredibly important when it comes to maintaining safety, improving performance, and material selection during the rocket’s production process. Current methods for testing and recording this snatch force are limited, so our team aimed to create a simple and cost effective solution. Our design utilizes a vertical support that …

Mems 4110: Asme Challenge, Jon Cossman, Jonathan Young, Nate Nowel

Mechanical Engineering Design Project Class

The goal of this project was to design and assemble a remote controlled device for a competition that can maneuver through a course, collect trash units from 3D-printed trash bins, and bring them to a receptacle at the end of the course. Important factors to consider in the design involved ensuring it followed traffic laws through the course, making sure it could operate multiple times, and fit within price and space constraints. Prototypes were tested against the ability to deliver 75 percent of trash units within 5 minutes, 50 percent of trash units within 5 minutes without any traffic violations, …

Feasibility Of Helium And Nitrogen As Surrogate Gases For Hydrogen Jet Using Planar Laser-Induced Fluorescence In A Constant Volume Chamber, Jungho Justin Kim, Seong Young Lee, Youngmin Ki, Joonsik Hwang, Choongsik Bae

Michigan Tech Publications

This study investigates the feasibility of using helium and nitrogen as surrogate gases for visualizing the non-reactive behavior of hydrogen jets in a constant volume chamber. Hydrogen, helium, and nitrogen were individually mixed with acetone vapor and injected using a hollow-cone injector. The fuel distribution was visualized using Planar Laser-Induced Fluorescence (PLIF), while simultaneous Schlieren imaging was employed to capture overall jet structures. Quantitative comparisons of jet areas extracted from both imaging techniques demonstrated that acetone effectively followed the gas-phase flow of each species, validating its use as a flow tracer. Furthermore, helium and nitrogen exhibited jet dispersion patterns comparable …

Wmu Maritime Affairs Conference 2025 : Transforming A Maritime Future : Digitalization And Decarbonization, World Maritime University

Books

No abstract provided.

Engineering, Innovation, And God’S Creation, Fred Haan

University Faculty Publications and Creative Works

Took place at YPPH Annual Retreat 2025 Coram Deo In the Presence of God Reflections on Biblical Christian Worldview at Pelita Harapan University on 9/26/2025 in Jakarta, Indonesia.

Hydrogen Embrittlement In Shot-Peened Steel, Jia-Huei Tien, David R. Johnson, David Bahr

15th International Conference on Shot Peening

This work investigates the role of shot peening on hydrogen embrittlement resistance in quenched and tempered 1070 steel. Thermal desorption spectroscopy results revealed that shot-peened specimens contained nearly twice the hydrogen (H) content of unpeened samples when charged under the same electrochemical conditions, suggesting the introduction of additional trapping sites occur during peening. The mechanism underlying this behavior can be associated with increased dislocation density and is more consistent with the HELP mechanism. Residual stress measurements show a significant relaxation of compressive stresses in shot-peened specimen after H charging, indicating H enhanced dislocation rearrangement. Both unpeened and peened specimens exhibited …

Anisotropic Residual Stress Measurements In Additively Manufactured 316 Stainless Steel Parts, Rajeshree Varma, Donovan Stumpf, Paul R. Mort

15th International Conference on Shot Peening

Additive manufacturing (AM) using laser powder bed fusion (L-PBF) is increasingly used to produce complex parts for industries like aerospace and medical devices. The intrinsic characteristics of AM – layer-wise deposition and rapid thermal cycling – generate significant, anisotropic, residual stresses that can compromise part quality and performance. Recent studies highlight how these stresses are strongly influenced by process parameters and build orientation. X-ray diffraction (XRD) techniques, including sin²ψ and advanced two-dimensional approaches, have become the preferred methods for non-destructive, directionally resolved measurement of residual stress in AM metals. This review surveys advancements in XRD residual stress methods with a …

From Strain To Stress: Stress Map Testing Of Almen Strips, Donovan Stumpf, Rajeshree Varma, Paul R. Mort

15th International Conference on Shot Peening

Almen strips have long been used to evaluate shot peening intensity, with arc height serving as a proxy for compressive residual stress. Stress mapping tests (SMT) in this work involve the controlled flattening of an Almen test strip onto a spatial pressure sensor, acting as an inferential measurement for the net bending moment caused by the relaxation of the peened strip. This work explores how stress mapping tests add insight into the stress state of Almen strips, potentially offering a fast and practical alternative to residual stress depth profiling. SMT data analysis provides a framework for relating Almen gauge height …

Fourier Analyses Of Optical Profilometry As An Inferential Measurement For Impact Coverage., Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A critical consideration in peening process design is achieving sufficient impact coverage. Conventional methods for assessing coverage rely on manual inspection, which is time-consuming and poorly suited for automated control. In this work, we investigate the use of frequency-domain analysis to quantify surface modification in peened samples using optical profilometry (OP) data. Three-dimensional surface maps of Almen strips were acquired using a high-resolution OP system and analyzed via fast Fourier transform (FFT) to compute spatial power spectral densities (PSDs). PSD maps and radially averaged profiles reveal consistent amplification of harmonic components similar to the nominal particle size, with increasing intensity …

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 …

Comparison Of Peening Effect Between Additive Manufacutred And Drawing Titanium Alloy, Hitoshi Soyama

15th International Conference on Shot Peening

Although additively manufactured (AM) metals are attractive materials, their remarkable weak fatigue properties are an obstacle to their practical application. Thus, post-processing to improve their fatigue properties is required. In the present study, powder bed fusion using laser sintering titanium alloy, i.e., PBF-LS/Ti6Al4V was treated by shot peening (SP), submerged laser peening (SLP), cavitation peening (CP), and fine particle bombarding (FPB), then the fatigue properties were investigated by a torsional fatigue test, comparing with drawing Ti6Al4V. It was revealed that the fatigue strength at 10⁷ was 446 ± 5 MPa for PBF-LS/Ti6Al4V treated by FPB+CP, 359 ± 9 MPa …

Reduced Order Approach For Peening Stress Field Variability, Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A common goal in shot peening research is to connect operational parameters to resultant residual stress fields, providing a means to control and optimize the effectiveness of surface treatment. In practice, experimental measurements of residual stresses are often averaged values over regions that are large in comparison to an impact dimple. In fact, the stochastic nature of impact locations leads to residual stress fields that are distributed. Finite element peening simulations confirm this observation. The goal of this report is to connect operational parameters to localized fluctuations in residual stress through probabilistic reasoning (Figure 1). In particular, the development of …

Adaptation Of Shot Peen Parameters For Gear Geometry, David J. Breuer, Beth Matlock

15th International Conference on Shot Peening

Shot peening is a well established process for the surface enhancement of gearing. Gearing is a primary example of a high cycle fatigue application that can benefit from residual stress enhancement. Designing shot peening parameters to specific gear geometry based on material, heat treatment, and surface finish is a more precise way to achieve better performance outcomes. One of the best tools to assist in the optimal shot peening is x-ray diffraction (XRD) and its ability to measure small differences that can result in significant performance outcomes. XRD residual stress measurements are a direct measurement of elastic strain. The diffraction …

Investigations On The Fatigue Strength Of Threads Produced By Different Fabrication Techniques, Philippe Du Maire, Jürgen Hoffmeister, Andreas Öchsner, Michael Johlitz

15th International Conference on Shot Peening

The increasing importance of sustainability in engineering demands the development of long-lasting, high-performance components that reduce material and energy consumption over time. This study investigates how different thread manufacturing processes, i.e., cutting, rolling, and deep rolling, affect the fatigue strength of bolts made from 42CrMo4+QT steel. Cylindrical specimens with M12 threads were subjected to cyclic tensile loading with constant mean stress. Fatigue strength was evaluated using the staircase method, and supporting analyses included X-ray diffraction for residual stress, and full width half maximum examination and Vickers microhardness measurements. Results show that thread rolling significantly improves fatigue strength, achieving 113.8 MPa …

Numerical Assessment Of Shot Peening Contribution To The Fatigue Strength Of Gear Tooth Root, Gurutz Cortabitarte Laucirica, Xuban Telleria, Iñigo Llavori, Ibai Ulacia, Miren Larrañaga, Jon Ander Esnaola

15th International Conference on Shot Peening

Gears are commonly treated with shot peening (SP) and/or case hardening to enhance fatigue resistance. However, their effects are often conservatively assessed using standardized methods, which can limit their optimal application in industrial components. Particularly, the effect of SP over case-hardened gears remains insufficiently explored. Therefore, the present study evaluates the contribution of SP on single tooth bending fatigue (STBF) strength of raw and case-hardened spur gears, commonly used in automotive and heavy machinery industries. In the study four conditions are addressed: (i) untreated, (ii) case-hardened, (iii) shot-peened, and (iv) case-hardened and shot-peened. First, the residual stress field of the …