Mechanical Engineering Commons^™

Additive Manufacturing Of Metals: Mechanical Properties And Their Implications, Sean Chih

Discovery Day - Daytona Beach

Additive manufacturing of metals is a relatively new and groundbreaking approach to manufacturing high-performance components. However, variability in mechanical properties from the process creates a barrier before this manufacturing technique can be widely applied. Understanding when and where to use this manufacturing is also important to create components with efficiency and without harmful defects. The objective of this research is to evaluate the effects of build orientation, printing parameters, internal defects, thermal history, and residual stresses, post-processing heat treatments, and fatigue behavior on additively manufactured components. Literature-based research is conducted on commonly used metals for additive manufacturing, such as stainless …

Influence Of Infill Geometry On The Vibrational Behavior Of 3d-Printed Cantilever Beams, Owen Maute

Discovery Day - Daytona Beach

Vibration and damping are important considerations in many engineering structures, especially as additive manufacturing becomes more widely used in functional mechanical components. This project investigates how the internal structure of 3D-printed parts affects their vibrational behavior. A series of cantilever beams with identical outer dimensions will be designed and manufactured using a 3D printer with PLA filament, since PLA is one of the most commonly used materials in consumer and prototyping-level additive manufacturing. The study will examine five different infill patterns at three different infill densities, producing multiple beam configurations that vary only in their internal geometry. In addition to …

Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer

Faculty Publications and Presentations

The Cosmic Fabric Model establishes a continuum-mechanics isomorphism to General Relativity by representing physical space as an elastic three-dimensional hyperplate embedded in a four-dimensional spatial bulk. Reproducing vacuum kinematics requires a vanishing P-wave modulus, which in turn implies a negative bulk modulus—an apparent thermodynamic instability in a closed system. This paradox is resolved by recasting the framework as an open system: the instability is not pathological but instead drives cosmic expansion. In this interpretation, the observable universe is a lower-energy solid formed through continuous solidification from a higher-dimensional precursor fluid. Using multiplicative kinematics from finite-growth mechanics, the model shows that …

Magnetic Field-Induced Transformation In Polycrystalline Ni2mnal Heusler Type Magnetic Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The martensitic and magnetic transformations, as well as the mechanical properties, of Ni₂MnAl alloys in as-cast (AC) and heat-treated (HT) conditions were investigated. Magnetic-field-induced strain was evaluated via magnetostriction, with reversible strains of 0.14% and 0.2% achieved in the martensitic phase at 2 K for the AC and HT alloys, respectively. Transformation temperatures and Curie temperatures were determined under constant applied magnetic field, revealing that γ-phase inclusions in the AC microstructure suppress antiferromagnetic domain response, yielding a lower magnetization (∼8.4 emu g⁻¹) compared to the HT alloy (∼13.4 emu g⁻¹). Both alloys exhibited hysteretic behavior in the martensitic state and …

Cal Poly Fluid Powered Vehicle Challenge 2025/2026, Ethan Malachi Nejame Zeiset, Christian Anthony Cuamani, Daniel Chacon-Bizarro, Marcus Minera, Bradley Hansell

Mechanical Engineering

In this Final Design Report, the Cal Poly Fluid Power Vehicle Challenge Contending Team competed in Sun Hydraulics’ 2026 Fluid Powered Vehicle Challenge. The objective of the competition is to expose college students to the fluid power sector, the “hidden giant” of the engineering industry. Specifically, student teams are tasked with the development of a human-powered, fluid-driven vehicle for use in various competitive settings. The team prioritized the optimization of an existing prototype for simplicity, ease of maintenance, and reliability during the competition. The existing prototype exhibited issues related to the main frame’s deflection under load, a lack of gear …

Electropulse Annealing: Phase Composition Of Tial6v4, Vaughn Eckhardt, Ethan Croke, Ian Baker, Russ Taylor

Wetterhahn Science Symposium Posters

Titanium alloy TiAl6V4 is the most ubiquitous titanium alloy used for dental care, aerospace manufacturing, and for high performance vehicles. The material typically undergoes a thermal heat  treatment, but electropulse annealing is another process that involves sending current through the material to heat it up at a quicker rate. The rate of post-annealing cooling is high, and around the material's critical point, its two components, alpha and beta phase, change in relative concentration. After testing multiple current densities and temperatures, in general, as the current density that the sample received during electropulse annealing decreased, both the alpha and beta phases …

Mechanical Characterization And Modeling Of Rat Myocardia Under The Influence Of Epirubicin, Abdallah Mahmoud Alkhaiyat

Theses and Dissertations

Cancer remains a predominant health challenge that is responsible for a significant portion of global morbidity and mortality. Epirubicin (EPI), a chemotherapeutic anti-cancer drug, has shown remarkable efficacy in combating various malignancies. However, it is known to have undesirable side effects on the heart, collectively referred to as cardiotoxicity. This research investigates the adverse effects of chemotherapy on cardiac contractility through an in vitro examination of the mechanics of healthy and infarcted animal heart tissues. Electrically stimulated slices of rat ventricular tissue were tested using an isometric force measurement tissue bath. The tissue slices were subjected to uniaxial stretching, allowing …

The Effects Of Mold Flux Contamination On Oxide Scale Formation And Hydro-Descaling Efficiency During Steel Processing, Tochukwu Princewill Ojiako, Richard Osei, Mario Buchely, Haiming Wen, Simon Lekakh, Ronald O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Oxide scale formation during thin-slab continuous casting has a complex structure, which is influenced by mold flux contamination, that modifies interfacial reactions during solidification, subsequent reheating, and descaling. While individual aspects of the oxidation behavior of carbon steel have been previously examined, the synergetic effects of mold flux contamination during continuous casting and subsequent reheating on scale modification and the efficiency of hydraulic descaling remain inadequately studied. This study quantitatively examines the effect of flux composition on oxide scale evolution, adhesion, and hydraulic removal in low-carbon steel under simulated industrial conditions. Slab samples with as-cast, cleaned, and flux-coated surfaces were …

Thermal Transformations And Mechanical Properties Of All-D-Metal Mn2fecu Heusler-Type Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely

Materials Science and Engineering Faculty Research & Creative Works

All-d-metal Heusler alloys are emerging functional materials in which magnetic ordering, lattice distortion, and mechanical behavior are strongly coupled through d–d electronic interactions. This study systematically investigates the structural, thermal, magnetic, and mechanical properties of Mn₂FeCu synthesized within a Heusler-type compositional framework. SEM/EDS revealed a dual-phase FCC-based microstructure consisting of Mn–Fe–rich and Mn–Cu–rich domains, while XRD confirmed FCC symmetry with compositional partitioning rather than full L2₁ ordering. Differential scanning calorimetry identified partial melting of the Cu-rich phase near ~ 900 °C. Dilatometry showed a thermoelastic FCC → FCT transformation at ~ 770–780 °C with a recoverable strain of ~ 0.067%. …

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Parts, Logan Trimmer

Harrisburg University Other Works

Presentation covering the broad strokes of the project. The goal was to prove the viability of hybrid/additive manufacturing for high stress automotive applications. This project focused on recreating a piston from an old engine to examine if hybrid manufacturing could be used for such applications. On a small scale, hybrid manufacturing was able to be more cost effective if the costs of the equipment and electricity were ignored. The decision to ignore those costs came from the inability to find accurate prices for industrial casting.

Akron Soap Box Derby Super Kids Car, Alexis Schultz, Cooper Sites, Sean Stevenson

Williams Honors College, Honors Research Projects

This project aims to redesign the All-American Soap Box Derby Super Kids vehicle to enhance safety, accessibility, and performance while maintaining full compliance with official regulations. The Super Kids program enables children with physical and cognitive disabilities to race alongside a co-pilot, but the current vehicle design presents challenges in stability, entry/exit accessibility, and control—especially following recent regulation changes that increased vehicle speed. The redesigned car will focus on improved ergonomics, lightweight construction, and structural integrity within a $1,000 budget and a 165 lb weight limit.

An iterative engineering design process will guide the project through research, CAD modeling, FEA …

Critical Parameters Controlling Oxide Scale Formation And Hydro-Descaling Efficiency During Steelmaking, Tochukwu Princewill Ojiako

Doctoral Dissertations

In modern steelmaking, cast slabs are exposed to high-temperature oxidizing environments during secondary cooling, reheating, and hot rolling, resulting in the formation of multilayer oxide scales on the steel surface. These scales interact with mold-flux residues originating from the casting process (CC). The morphology, chemistry, and adhesion of oxide scale strongly influence its removability during high-pressure hydraulic descaling and ultimately determine the surface quality of hot-rolled products. However, the mechanistic relationship between oxide scale evolution, scale-steel interfacial structure, and hydraulic descaling performance remains poorly understood.

This dissertation investigates oxide scale formation, modification, and removal in low-carbon thin-slab steels produced by …

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Components, Logan Trimmer

Harrisburg University Other Works

The goal of this research was to establish the viability of using hybrid manufacturing for automotive applications. By verifying that high-stress components can be created, it can be assumed that any other lower stress part could be made to match the strength requirements. A limiting factor of adoption for hybrid manufacturing is how new the technology is. Studies on time and cost were performed allowing for comparisons with traditional manufacturing technologies (casting, forging, milling) used in automotive applications. This research utilized a Haas Automation UMC750 5-axis CNC mill with a Meltio laser wire direct energy deposition attachment. Fusion 360 was …

Entropic Forces Near Fluctuating Surfaces, Rubayet Hassan

Dissertations

Nanoscale structures are inherently dynamic due to persistent thermal fluctuations. Even in solid materials, these random deformations, driven by ambient thermal energy, can become significant when their characteristic scale approaches that of the structure itself and strongly influence their overall mechanical behavior. Examples of such structures include crystalline membranes, appearing in diverse forms such as nanotubes, nanoribbons, and kirigami/origami structures. Similarly, biological nanostructures, including lipid membranes, microtubules, actin filaments, and DNA, exhibit extreme flexibility and responsiveness due to their low bending rigidity. Numerous physiological processes are intrinsically linked to these thermal fluctuations, including exocytosis and endocytosis, membrane fusion, pore formation, …

Powder Degradation Analysis In Reused Pure Tungsten For Electron Beam Melting (Ebm), Hernan Valenzuela

Open Access Theses & Dissertations

Additive manufacturing (AM) enables unparalleled design freedom and geometric complexity, driving its adoption in aerospace and medical fields. A major advantage of metal powder AM technologies, such as Electron Beam Melting (EBM), is its ability to reuse unused metal powder, reducing material waste and costs. However, reusing powder repeatedly alters its properties, affecting the final product. Despite its significance, research on powder degradation remains limited, primarily focusing on alloys like Ti-6Al-4V. This thesis investigates the degradation of pure tungsten powder reused over multiple Electron Beam Melting (EBM) cycles. A literature review revealed general powder-reuse mechanisms across additive manufacturing (AM) technologies …

Coupling Material Formulation Strategies To Tailor Piezoelectric Properties Of Ceramic Lattices, Amanda Lauren Borgaro

Open Access Theses & Dissertations

This thesis examines the material formulation and infiltration processes required to create interpenetrating ceramic composites with a particular focus on developing piezoelectric ceramic-epoxy lattice structures (PCELS). Following this, a high–solid loading barium titanite photopolymer resin (BT40) was developed to produce BTO scaffolds with controlled porosity suitable for metal infusion. The resin’s shear-thinning behavior and scattering-dominated curing response enabled the formation of stable, uniform ceramic structures whose pore networks directly influence infiltration behavior. Building on this foundation, a low-temperature Field’s Metal (FM) infiltration method was established using controlled thermal equilibration and the melting of pre-formed alloy rods. By maintaining the ceramic …

Decoupling Piezoelectric And Pyroelectric Effects In Anisotropic Polymer-Ceramic Lattices Produced Via Fused Filament Fabrication, Sofia Alexandra Perez

Open Access Theses & Dissertations

This thesis investigates how multi-material fused filament fabrication (FFF) can be used to engineer lattice structures that decouple piezoelectric and pyroelectric responses within a single polymer–ceramic composite. A hybrid ABS–BaTiO3/PLA lattice—referred to as the Hybrid PIZCAL—was designed to direct mechanical strain along the Z-axis while suppressing deformation in the transverse directions. After thermal poling, the lattice exhibited a 293% increase in Z-axis voltage sensitivity compared to a monolithic ABS–BaTiO3 cube and significantly reduced off-axis electromechanical output. Finite element simulations and directional compression testing confirmed that geometric anisotropy and material zoning produce strong, axis-selective piezoelectric behavior. The second part of this …

Characterization Of The Fatigue Threshold Behavior Of Uhmwpe, Bethany B. Smith, Anurag Roy, Robert O. Ritchie, Lisa A. Pruitt

Faculty Journal Articles

Ultra-high-molecular-weight-polyethylene (UHMWPE) has been the material of choice for bearings in total joint replacements (TJRs) for decades as a result of its excellent wear resistance, chemical inertness, energetic toughness, low friction, and biocompatibility. Utilization of this polymer in orthopedic devices requires oxidation, wear, and fatigue resistance. Balancing these important properties by tailoring processing techniques and modulating microstructural features has been an ongoing endeavor in the field. Research into the clinical applications of UHMWPE has primarily focused on the challenges of wear and oxidation while studies into the realm of fatigue have been more limited. Literature gaps exist in fully understanding …

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 …

Expansion Of Laser Peening Application With A High-Power Microchip Laser On A Robotic Arm, Yuji Sano, Yoshio Mizuta, Satoshi Tamaki, Tomonao Hosokai, Tomoharu Kato, Yoshihiro Sakino, Volker Schneidau, Sebastian Holz, Jörg Behler

15th International Conference on Shot Peening

Laser peening (LP) introduces compressive residual stress (RS) onto the surface of metallic materials using nanosecond laser pulses irradiated through a water layer, thereby effectively suppressing fatigue crack initiation. However, conventional LP systems require large, stationary setups, restricting their use to indoor environments. To overcome this limitation, a portable LP device featuring a finger-sized microchip laser mounted on a collaborative robot arm has been developed. Equipped with a compact power supply and a water circulation/recovery system, the device can operate on-site with minimal setup. Successful processing across various materials has confirmed both compressive RS induction and fatigue life extension. Notably, …

Effects Of Laser Peening On Fatigue Properties Of Welded Aluminum Thin Plates, Kiyotaka Masaki, Yoshio Mizuta, Satoshi Tamaki, Yuji Sano

15th International Conference on Shot Peening

To improve the fatigue properties of welded aluminum alloy thin plates used in transportation machinery, handheld laser peening (HH-LP) was applied to 2 mm-thick A5083-O specimens prepared by bead-on TIG welding. Conventional laser peening often causes warping in thin plates, but the HH-LP treatment using low-energy laser pulses avoids this problem. The HH-LP treatment introduced compressive residual stresses of over 200 MPa on the heat-affected zone (HAZ) of the welded specimens. Fatigue tests under plane bending conditions revealed that the HH-LP treatment significantly improved the fatigue strength of the welded specimens, achieving a level comparable to that of the base …

Shape Memory Behavior In Medium To High Entropy Shape Memory Alloys: Design, Prediction, And Experimental Analysis, Hatim Raji

Theses and Dissertations

This dissertation provides a data-driven system integrating synthetic data generation and machine learning (ML) techniques to create multicomponent SMA compositions with specific transformation temperatures (TTs). Models were trained to represent the nonlinear dependencies influencing martensitic transformation behavior by using elemental, thermodynamic, and process-related aspects. The capacity of the ML models on medium entropy NiTiHfPd and high entropy NiTiHfZrCu systems accuracy was confirmed by experimental validation showing TTs closely matched with model outputs.

Advancing Multi-Physics Modeling For Microwave Heating: Application In Micro-Reactor Design And Optimization, Raghav Adhikari

All Theses

Microreactors are a type of small-scale chemical reactors for achieving reduced volume, improved product selectivity and higher reaction rate. It allows precise temperature control, which is crucial for sensitive chemical processes. Microreactors can be employed as key components of conducting small-scale reactions with improved reactor configuration and process efficiency. It is important to identify a localized and precise heating mechanism to trigger and control the corresponding chemical reactions.

In fact, microwave heating has gathered significant attention in recent years due to its ability to deliver efficient, rapid, and localized heating, which can accelerate reaction rates and enhances the reaction selectivity. …

Comparative Study Of Experimental And Fea Strain Data For Cnt-Coated Fiberglass Sensors, Extensometers, And Metal Foil Strain Gauges, Omar Dwidar

Master's Theses

Material testing is essential across industries such as aerospace, automotive, and construction, playing a critical role in verifying material selection, diagnosing failures, and understanding the development of flaws in structures. These insights are key to designing successful, reliable systems. Conventional metal foil strain gauges are low cost and reliable but provide limited sensitivity with a typical gauge factor around 2. Extensometers provide highly sensitive strain measurements with the disadvantage of a bulky form factor. With advanced materials such as carbon nanotubes, it is possible to manufacture a sensor with the sensitivity closer to that of an extensometer with the small …

Tailoring Functional And Sensing Properties Of Polymer-Ceramic Composites Via 3d Printing, Alexis Lopez

Open Access Theses & Dissertations

Section 1.1. Abstract This chapter investigates the use of direct ink write (DIW) additive manufacturing to control grain orientation in non-toxic barium titanate (BTO) ceramics by blending spherical and platelet-shaped particles in the ink. A series of inks containing 0–40 wt.% BTO platelets were formulated with poly(vinyl alcohol), polyethylene glycol, poly(acrylic acid-co-maleic acid), and ammonium hydroxide to ensure printability and homogeneous dispersion. Cylindrical specimens (20 mm × 3 mm) were printed using a Hyrel 30M DIW system and subjected to de-binding (650 °C, 2 h) followed by a two-step sintering schedule (T₁: 1200–1350 °C; T₂: 700–850 °C; 24 h dwell). …

Mechanistic Insights Into Polymer-Assisted Graphene Exfoliation: The Roles Of Velocity, Adhesion, Cohesion, Temperature, Peeling Mode, And Edge Defect Via Coarse-Grained Molecular Dynamics, Linjiale Dai

All Theses

Graphene exfoliation is a critical step in the fabrication of high-quality graphene

layers. However, the underlying fracture mechanisms remain poorly understood. In this

work, I employed coarse-grained (CG) molecular dynamics (MD) simulations to

investigate how factors such as interfacial binding energy, substrate cohesion, temperature,

peeling mode, and edge defects influence the outcome of the exfoliation process. To model

polymer-assisted mechanical exfoliation, I used a finite-size system in which multilayer

graphene (MLG) is sandwiched between two thin polymer films. Leveraging the

spatiotemporal efficiency of the CG model, I performed fifty simulation iterations per

parameter set and analyzed the results from a …

Experimental And Theoretical Fracture Analysis Of Additively Manufactured Orthotropic V-Notches, Venkata Siva Sainath Bavapuram

Theses and Dissertations

This study presents a comprehensive investigation into the fracture behavior of additively manufactured orthotropic V-notched components made of Acrylonitrile Butadiene Styrene (ABS) material. The research integrates both theoretical and finite element approaches to evaluate stress intensity factors (SIFs) in Modes-I and II, which are fundamental in characterizing stress field distributions around notches under applied loading conditions. Unlike isotropic materials, where stress fields depend only on geometry of the component, the anisotropic nature of 3D-printed ABS introduces a dependency on material properties that necessitate different approaches to include anisotropy of the material.

Tensile specimens are 3D-printed with specific material orientations to …

Approach Formula To Increase Energy Efficiency Of Internal Combustion Engines In The “Green Economy” And Impact On The Natural Ecosystem, Zakirjon Ergashevich Musabekov, Hilola Zokir Qizi Uralova, Sayyodbek Ilxomjon O‘G‘Li Abdullajonov

Technical science and innovation

This article discusses, analyzes, and proposes solutions for the role of internal combustion engines in forming a "green economy", as well as ways to replace or modernize them. The relationship between internal combustion engines and the "green economy," as well as their energy efficiency and impact on natural ecosystems, is a crucial and urgent issue. These engines primarily generate energy through the combustion of petroleum-based fuels such as gasoline and diesel. However, this process releases harmful gases into the atmosphere, contributing to environmental degradation. The green economy is an economic model designed to protect the environment, ensure the efficient management …

Improvement Of Microcracking And Mechanical Properties Of Tungsten Fabricated Via Laser Powder Bed Fusion Through Alloying With Reactive Secondary Constituents, William S. Mockel

Theses and Dissertations

Tungsten (W), a Group VI transition metal, possesses a number of advantageous properties, most notably its impressive mechanical performance at extreme temperatures. While tungsten's nature render traditional manufacturing methods difficult, additive manufacturing through laser powder bed fusion (LPBF) presents a promising avenue for fabricating tungsten components. However, the material’s high ductile-to-brittle transition temperature combined with the embrittling effect of impurities mean that the residual stresses imparted by LPBF result in microcracking in tungsten, degrading its usefulness. This study sought to improve the characteristics of LPBF-W through the removal of embrittling oxygen content via alloying with low concentrations of reactive elements, …

Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

Nitrogen pickup during air induction melting can result in porosity and a loss of fracture toughness in ultrahigh-strength quenched and tempered steel castings. Nitrogen atoms are easily adsorbed into liquid steel upon exposure to the air, and argon shrouding alone has limited effectiveness. Previous studies have shown that proper charge sequencing and maintaining a high amount of dissolved oxygen in the melt prior to tapping and deoxidation can limit nitrogen pickup in the melt. In the current study, the effect of melt practice and charging procedure on nitrogen pickup was studied as a function of hold time in a series …