Mechanical Engineering Commons^™

Sensitivity Study Regarding Abs Formulation On Hybrid Rocket Performance, Ava T. Wilkey, Ryan J. Thibaudeau, Stephen A. Whitmore

Mechanical and Aerospace Engineering Student Publications and Presentations

Acrylonitrile butadiene styrene (ABS) has emerged as a widely adopted solid fuel for hybrid rocket propulsion due to its compatibility with fused deposition modeling and favorable regression characteristics. As a terpolymer, however, ABS monomer mass fractions vary across commercial sources, introducing thermochemical variability that is rarely accounted for in propulsion modeling. This study presents a sensitivity analysis examining how compositional variability among ten commercially available ABS feedstock propagates into hybrid rocket performance predictions. Each source was characterized using bomb calorimetry and Fourier-transform infrared spectroscopy to derive source-specific constituent mass fractions and enthalpies of formation, which were supplied to NASA’s Chemical …

Direct Ink Writing Of Functional Fiber/Granular Composites, Zhuoyuan Yang

Doctoral Dissertations and Master's Theses

Direct ink writing provides a versatile manufacturing route for fabricating functional fiber and granular composites with controlled architecture, tunable interfaces, and customized material distributions. Fiber reinforced composites offer high stiffness, strength, fatigue resistance, and functional anisotropy, while granular composites provide scalable access to particle based structures with high material efficiency and broad resource compatibility. However, the additive manufacturing of these composite systems remains challenging. For fiber based composites, precise control of fiber placement, matrix impregnation, interfacial bonding, and freestanding deposition is difficult to achieve during printing. For granular composites, stable particle flow, controllable packing, binder infiltration, and shape retention are …

A Novel Hexagonal-Zigzag Cellular Infill Structure For Additive Manufacturing, Md. Saidur R Roney, Amm Nazmul Ahsan, Prosenjit Barua

Manufacturing & Industrial Engineering Faculty Publications

The rigidity of the Additively Manufactured objects can be tailored by manipulating the infill lattice type and density. In this research, an island type novel infill structure termed as Hexagonal-Zigzag pattern is introduced, and its mechanical performance is investigated. In this pattern, the zigzag raster reflects the repeating hexagonal shaped cell constituting the parallel-oriented islands and 90° rotation of the pattern in each layer distributes the island span along both transverse and longitudinal directions of the printing contour. A mathematical model is established to illustrate the effect of the infill parameters on hexagon unit cell size and relative infill density. …

Simulation Of Powder Spreading For Metal Additive Manufacturing, Florence Duff

Master's Theses

The powder recoating process for Laser Powder Bed Fusion requires iterative experimentation to develop the correct process parameters that will result in high quality parts. There currently lacks good spread quality metrics and models for optimizing spread quality. A machine that simulates the powder spreading process was built to streamline the process of selecting process parameters for specific types of powders without having to operate the full laser system. The parameters investigated were the layer thickness and spreading speed. The response variables were metrics developed to assess spread quality: the percentage of the build plate covered by powder and the …

Effects Of Niobium On The Mechanical And Oxidation Properties Of Additively Manufactured Tungsten, Alexander Lesieur, Cayla Eckley, Ryan A. Kemnitz

Faculty Publications

Although additive manufacturing presents a novel and customizable approach to fabricating tungsten (W) alloys, the layer-by-layer production technique presents a unique set of processing challenges which are further exacerbated by the metal’s refractory properties. In this study, additions of niobium (Nb) were found to improve the mechanical properties and oxidation resistance of additively manufactured W. Microstructural investigation revealed the effect of Nb on the cracking, grain size, and texture in the as-built material. Mechanical compression testing showed significant improvement in ductility with increasing Nb content. The low concentrations of Nb used did not induce large changes in the yield strength …

Quantitative Phase-Field Modeling Of Nonequilibrium Microstructural Evolution In Rapid Solidification For Additive Manufacturing, Leiji Li, Fei Xiao, Ying Zhou, Xiaorong Cai, Chongfeng Zhang, Jinzhong Gao, Xiaopeng Shen, Tianchi Zhu, Sihan Wang, Yijia Gu, Xuejun Jin

Materials Science and Engineering Faculty Research & Creative Works

Fusion-based metal additive manufacturing (AM) relies on layer-by-layer deposition and rapid solidification, where the material transitions swiftly from liquid to solid. A key phenomenon during this process is solute trapping, a nonequilibrium effect governed by a velocity-dependent partition coefficient, which critically influences microstructure kinetics, morphology, and phase formation. In this study, we employ a recently proposed quantitative phase field (PF) model to systematically explore solute trapping, solute drag, and their impacts on pattern formation during rapid solidification at AM-relevant velocities, in both one and two dimensions. Our simulations reveal a growth mode transition from planar to cellular to dendritic, and …

Roadmap On Artificial Intelligence-Augmented Additive Manufacturing, Ali Zolfagharian, Liuchao Jin, Qi Ge, Wei-Hsin Liao, Andrés Díaz Lantada, Francisco Franco Martínez, Tianyu Zhang, Tao Liu, Charlie C.L. Wang, Mohammad Hossein Mosallanejad, Reza Ghanavati, Abdollah Saboori, Alejandro De Blas De Miguel, William Solórzano-Requejo, Yi Cai, Xiangyang Dong, Huangyi Qu, Najmeh Samadiani, Guangyan Huang, Austin Downey, Yanzhou Fu, Lang Yuan

Faculty Publications

Artificial intelligence-augmented additive manufacturing (AI2AM) represents a transformative frontier in digital fabrication, where artificial intelligence (AI) is embedded not as a peripheral tool, but as a central framework driving intelligent, adaptive, and autonomous additive manufacturing (AM) systems. The objective of this Roadmap is to present a comprehensive vision of the state-of-the-art developments in AI2AM while charting the future trajectory of this rapidly emerging field. As AM applications continue to expand across diverse sectors, conventional design and control strategies face growing limitations in scalability, quality assurance, and material complexity. AI uses tools like computer vision, generative design, and large language models …

Investigation Of Process Parameters To Fabricate Tiwmo Refractory Medium Entropy Alloy Via Laser Powder Bed Fusion, Abdullah Al Masum Jabir, Lindsey A. Salazar, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications

This paper presents an experimental study on the fabrication of a TiWMo refractory medium-entropy alloy (RMEA) using laser powder bed fusion (PBF-LB/M, commonly known as selective laser melting) from elemental powders as well as successful alloy formation on titanium substrates. The effects of tungsten particle size and process parameters on successful TiWMo RMEA fabrication have been explored using scanning electron microscopy (SEM), x-ray diffraction, hardness measurement and microstructural analysis. Scanning electron microscope (SEM) analysis revealed that the lowest percentage (0.01%) of unmelted tungsten particles was observed at a laser power of 350 W and scanning speed of 250 mm/s, particularly …

Artificial Intelligence And Additive Manufacturing As A Coupled Design System: Rethinking Inference, Manufacturability, And Design Education, Charul Chadha, Garth Crosby, Sabit Ekin, Mohamed Gharib, Eman Hammad, Congrui Jin, Ali Ahmad Malik, Noemi Mendoza Diaz, Calahan Mollan, Monsuru Ramoni

Manufacturing & Industrial Engineering Faculty Publications

Artificial intelligence (AI) is becoming deeply integrated into additive manufacturing (AM) workflows, reshaping how designers approach geometry, materials, and process constraints. AI holds significant potential by accelerating design exploration, revealing complex patterns in AM behavior, and supporting earlier assessment of manufacturability. At the same time, it introduces new risks related to model transparency, data quality, physical validity, and the potential for overreliance by students and practitioners. This perspective examines these issues through four guiding questions that address the role of AI in AM-enabled design, the gaps that limit or enable AI contribution, the implications for engineering education, and the responsibilities …

Overcoming Resolution Vs. Throughput Trade-Offs In Ceramic Material Extrusion Additive Manufacturing Via Viscoelastic Filament Stretching, Abid H. Rafi, David W. Lipke, Jeremy L. Watts, Gregory E. Hilmas, Ming C. Leu

Materials Science and Engineering Faculty Research & Creative Works

Fabricating large, monolithic ceramic parts using material-extrusion additive manufacturing remains challenging due to difficulty maintaining uniform moisture content during printing, which can lead to drying-induced defects such as warping and cracking, especially as part size and print time increase. Fabricated parts have trade-offs among print resolution, high throughput, and structural fidelity. Our study has shown that increasing the ratio of nozzle traverse speed vs. material extrusion speed increases filament stretching in viscoelastic ceramic paste, helping to overcome the trade-offs between resolution and throughput. Using aqueous ZrB2–SiC (70/30 vol.%) as a representative ultra-high temperature ceramic paste, rheological characterisation revealed viscoelastic yield-stress …

A Full Polymer Piezoelectric Flextensional Energy Harvester, Nadia Ahbab, Sidra Naz, Bingqi Zhao, Tian-Bing Xu

Mechanical & Aerospace Engineering Faculty Publications

This study presents a full polymer piezoelectric flextensional energy harvester (FPPFEH) comprising a single-layer poly(vinylidene fluoride) (PVDF) film bonded to a 3D-printed polylactic acid (PLA) flextensional frame. For an arm inclination angle of θ=10°, the free-body model gives a theoretical geometric force-amplification factor of M_F=cot θ ≈ 5.67; this value represents an ideal upper bound and was not independently validated by local force or strain measurements. During assembly, the film was tensioned only to remove visible slack and maintain a flat configuration. No intentional pretension was applied, and any residual tension was not measured. Off-resonance force-controlled tests showed …

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.

Nondestructive Evaluation Of Additively Manufactured Parts Using Resonant Inspection And Frequency Domain-Based Correlation Criteria, Gita Deonarain

Dissertations, Master's Theses and Master's Reports

Additive manufacturing (AM) enables the production of highly customized and geometrically complex components; however, these parts remain susceptible to a wide range of defect types and severities. The combination of complex geometries and distributed defects presents a significant challenge for post-process nondestructive evaluation (NDE). Conventional inspection techniques, such as computed tomography and ultrasonic testing, are often limited by geometry, material, accessibility, and cost, while in situ monitoring is not yet sufficiently mature to replace post-process inspection.

This dissertation establishes the Frequency Domain Assurance Criterion (FDAC) as a quantitative, vibration-based framework for defect detection in AM components. FDAC captures spatial–spectral correlations …

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 …

Influence Of Build Plate Location On Tensile Properties And Residual Stresses In Lpbf-Fabricated Stainless Steel 316 Components, Yareli Zelaya Pavón

Honors Program Theses and Research Projects

Additive manufacturing (AM), particularly Laser Powder Bed Fusion (LPBF), enables rapid production of complex metal components with minimal waste. Stainless Steel 316 (SS316) is widely used in engineering applications due to its corrosion resistance and mechanical reliability. This study investigates the influence of build plate location on tensile properties and residual stresses in LPBF-fabricated SS316. Twelve tensile specimens and nine unsupported bridge structures were fabricated at different build plate positions using a “machine model.” Tensile testing provided stress-strain data to evaluate peak stress, elastic modulus, and strain at break, while bridge curvature measurements quantified residual stress through warping. Results indicate …

Bending Fatigue In Additively Manufactured Metals: A Review Of Current Research And Future Directions, Md Bahar Uddin, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metal additive manufacturing (MAM), also referred to as 3D printing, has proven remarkable in the fabrication of complex metal components in multiple sectors. However, the assessment of this revolutionary process through bending fatigue is frequently impeded due to concerns about mechanical and physical conditions of the printed components. The unique layer-by-layer production process results in varied microstructures, anisotropy, and intrinsic defects that considerably differ from traditionally manufactured wrought metals. This review article aims to integrate and evaluate historical and contemporary research on the bending fatigue of additively manufactured materials. More specifically, the impact of process parameters, build orientation, surface conditions, …

Hybrid Multi-Layer Sandwich Beams Using 3d Printing Technology With Energy Absorption Features, Hour Ali Alhefeiti

Thesis/ Dissertation Defenses

This study explores the use of additive manufacturing (AM) technology to create sandwich composite structures, focusing on the manufacturing process, testing, and anticipated impact. The rising cost of manufacturing prototypes using conventional methods has led to the exploration of 3D printing as a viable alternative. The research problem addresses the challenges in manufacturing sandwich composites and the need for automation across the civil, mechanical, aerospace, and aviation industries. The study aims to investigate 3D-printed sandwich composite structures and compare experimental, finite-element analysis, and theoretical results. The proposed methodology includes preparing a CAD model with five different core infill patterns (Cross …

Experimental Investigation Of 3d Printed Tpu Triboelectric Composites For Biomechanical Energy Conversion In Knee Implants, Osama Abdalla, Milad Azami, Amir Ameli, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Although total knee replacements have an insignificant impact on patients’ mobility and quality of life, real-time performance monitoring remains a challenge. Monitoring the load over time can improve surgery outcomes and early detection of mechanical imbalances. Triboelectric nanogenerators (TENGs) present a promising approach as a self-powered sensor for load monitoring in TKR. A TENG was fabricated with dielectric layers consisting of Kapton tape and 3D-printed thermoplastic polyurethane (TPU) matrix incorporating CNT and BTO fillers, separated by an air gap and sandwiched between two copper electrodes. The sensor performance was optimized by varying the concentrations of BTO and CNT to study …

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 …

The Effect Of Surface Treatment On The Fatigue Strength Of Sus316l Additive Manufactured Products, Hitoshi Nishijima, Yuji Kobayashi, Toshiya Tsuji, Kiyotaka Masaki

15th International Conference on Shot Peening

Rotating bending fatigue tests were conducted to investigate the effect of shot peening and barrel finishing on fatigue properties of SUS316L made by laser PBF which was one of additive manufacturing processes. Surface roughness, residual stress, and fatigue strength were investigated for each specimen. As a result, the fatigue strength of the barrel finished specimens was almost same or better than that of the shot peened specimens. Barrel finished specimens increased 4.1 times higher fatigue strength than as-built specimens. The surface roughness of the specimens after barrel finishing was reduced by up to 96% compared to the as-built specimens. On …

Digital Twins, Ai, And Cybersecurity In Additive Manufacturing: A Comprehensive Review Of Current Trends And Challenges, Md Sazol Ahmmed, Laraib Khan, Muhammad Arif Mahmood, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The development of Industry 4.0 has accelerated the adoption of sophisticated technologies, including Digital Twins (DTs), Artificial Intelligence (AI), and cybersecurity, within Additive Manufacturing (AM). Enabling real-time monitoring, process optimization, predictive maintenance, and secure data management can redefine conventional manufacturing paradigms. Although their individual importance is increasing, a consistent understanding of how these technologies interact and collectively improve AM procedures is lacking. Focusing on the integration of digital twins (DTs), modular AI, and cybersecurity in AM, this review presents a comprehensive analysis of over 137 research publications from Scopus, Web of Science, Google Scholar, and ResearchGate. The publications are categorized …

Impact Of Print Speed And Nozzle Temperature On Tensile Strength Of 3d Printed Abs For Permanent Magnet Turbine Systems, Wirawan Wirawan, Hilmi Iman Firmansyah, Satworo Adiwidodo, Mohammad Sukri Mustapa

Journal of Mechanical Engineering Science and Technology (JMEST)

Operational parameters must be integrated into turbine systems' main components, which are determined by turbine systems' functional requirements. The need for producing component designs more effectively raises the possibility of using additive manufacturing. The study focuses on the optimization of the mechanical properties of the principal components of magnetic turbines manufactured with 3D printers using Acrylonitrile Butadiene Styrene (ABS), by changing the temperature and speed of the nozzle. The approach consisted of modeling a standard test piece in CAD software and producing ABS-based test pieces using a 3D printer with print speeds of 50, 70, 90, and 110 mm/s and …

3d Printed Cnt/Tpu Triboelectric Nanogenerator For Load Monitoring Of Total Knee Replacement, Osama Abdalla, Mahmood Chahari, Milad Azami, Amir Ameli, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This study presents the development and characterization of a novel triboelectric nanogenerator (TENG) designed as a self-powered sensor for load monitoring in total knee replacement (TKR) implants. The triboelectric layers comprise a 3D-printed thermoplastic polyurethane (TPU) matrix with carbon nanotube (CNT) nanoparticles and kapton tape, sandwiched between two copper electrodes. To optimize sensor performance, the proposed CNT/TPU TENG sensor is fabricated with varying CNT concentrations and thicknesses, enabling a comprehensive analysis of how material composition and structural parameters influence energy harvesting efficiency. The 1% CNT/TPU composite demonstrates the highest power output among the tested samples. The solid CNT/TPU-based TENG generated …

Surface Resistivity Correlation To Nano-Defects In Laser Powder Bed Fused Molybdenum (Mo)-Silicon Carbide (Sic) Alloys, Andrew Mason, Larry W. Burggraf, Ryan A. Kemnitz, Nate Ellsworth

Faculty Publications

The integration of Silicon Carbide (SiC) nanoparticles into Laser Powder Bed Fusion (LB-PBF) Molybdenum (Mo) printing represents a significant advancement in refractory metal additive manufacturing. Our investigation examined how varying SiC nanoparticle sizes affect the microstructural and electrical properties of LB-PBF-printed molybdenum components while maintaining a 0.01 mass fraction of Mo. At an Linear Energy Densities (LED) of 1.8 J/mm, the addition of 80 nm SiC particles achieved a 46% reduction in porosity, while sheet resistance decreased by 6% at LED of 2.0 J/mm with 80 nm SiC particles. These performance improvements stem from several mechanisms: SiC particles serve as …

Advancing Additive Manufacturing For Extreme Environments Through Simulated Microgravity Printing, Laura Nayeli Molina

Open Access Theses & Dissertations

Additive Manufacturing (AM) holds significant potential for space exploration by enabling on-demand fabrication of components, reducing payload costs, and enhancing mission adaptability. However, microgravity introduces challenges in thermal regulation, material deposition, and structural integrity. This research explores the feasibility of submerged AM using neutral buoyancy in silicone oil to simulate microgravity conditions on Earth. A 3D printer was modified for submerged operation, with samples printed under three conditions: no oil (ambient air), submerged in oil, and simulated microgravity at varying temperatures. Mechanical tests, fracture surface analysis, and density measurements were performed to evaluate tensile strength, surface adhesion, and dimensional stability. …

Open Accessarticle Crystal Plasticity Modeling Of Dislocation Density Evolution In Cellular Dislocation Structures, Md Mahabubur Rohoman, Caizhi Zhou

Faculty Publications

The complex thermal cycles during the solidification process in metal additive manufacturing (AM) lead to the formation of high-density dislocation networks, organizing into submicron-scale cellular structures. These ultrafine structures are recognized as crucial for enhancing the mechanical properties of AM metals. In this study, we investigate the evolution of dislocation density within these cellular structures under plastic deformation and its impact on mechanical response using dislocation density-based crystal plasticity finite element (CPFE) modeling. The model incorporates the evolution of both statistically stored dislocation (SSD) and geometrically necessary dislocation (GND). Our simulations reveal that the yield and flow stresses of dislocation …

Impact Of Delayed Artificial Aging On Tensile Properties And Microstructural Evolution Of Directed Energy Deposited Scalmalloy®, Rachel Boillat-Newport, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Scalmalloy® is a novel alloy designed to work with the unique processing inherent in additive manufacturing (AM). This alloy is post-processed using a single artificial aging treatment rather than a multistep heat treatment, as often noted in traditional manufacturing processes. Much of the literature details the impact of direct aging treatments around the temperature and time recommended by the manufacturer, 325 °C for 4 h; however, few studies have explored the impact of delayed artificial aging on the resulting mechanical and microstructural behavior. This study explored this missing link and determined the impact that the time between the fabrication of …

Additive Manufacturing Applications In Mission-Critical Operations: A Review, Arup Dey, Olusanmi Adeniran, Monsuru Ramoni

Manufacturing & Industrial Engineering Faculty Publications

Additive manufacturing (AM) is used to fabricate complex components from a wide variety of materials in an additive manner. AM brings several benefits, such as reduced lead times, on-demand production, creation of complex customized designs without tooling requirements, and remote design sharing. However, the use of AM for critical components is limited in large missions due to quality and reliability concerns, as is the case with many manufacturing technologies. Enhancing the acceptance of AM-built parts for mission-critical components can be achieved by producing highly reliable parts, establishing robust quality standards, and continually improving part properties. This review article comprehensively explores …

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …

Oxidation–Reduction Of Ti-6al-4v In Direct Energy Deposition Subject To Minimum Argon Consumption, Bharadwaja Ragampeta, Prashansa Ragampeta, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ti-6Al-4V is a well-known alloy for its low density and excellent corrosion resistance, making it popular in aerospace, marine, medical, and automotive applications. However, at elevated temperatures, the alloy forms oxides, leading to embrittlement. In additive manufacturing, particularly in the direct energy deposition (DED) process, which involves high temperatures, the alloy experiences oxidation. An inert gas chamber provides shielding during the process but limits the size of the manufactured components, and deposition in a vacuum chamber can alter the chemical composition of the alloy. Local shielding is a technique generally used for such applications, but it uses a high volume …