Mechanical Engineering Commons^™

Multiaxial Stress And Deformation Analysis In Mechanical Structures Under Variable Dynamic Loads, Aqeel Naeem Fareed Al-Khafaji

Al-Esraa University College Journal for Engineering Sciences

Piping supports in gas and process facilities in Iraq are routinely exposed to operational vibration and moderate seismic actions, creating multiaxial, variable dynamic loads that are not fully captured by conventional uniaxial, static design checks. Welded brackets, in particular, are prone to local stress concentration and fatigue at weld toes. This study aims to quantify the multiaxial stress and deformation response of a welded steel pipeline support bracket under variable dynamic loading and to assess the implications for structural integrity and design practice. It was demonstrated by the development and validation of a three-dimensional finite element model of a bracket-pipe …

Characteristic Stress And Strain Optimization Of Cardiovascular Catheters With Laser-Cut Hypotubes Using Finite Element Analysis, Kyle E. Hirth

Master's Theses

Cardiovascular catheter systems rely on laser-cut hypotubes to balance flexibility and structural integrity required for minimally invasive surgical procedures.  Optimizing these mechanical characteristics remains a significant challenge.  This study aims to investigate the influence of key laser-cut geometric parameters on the mechanical performance of hypotubes through finite element analysis.

Commercially representative laser-cut hypotubes were modeled and a finite element model was developed.   Geometric design parameters were varied across a design space consisting of pitch values ranging from 0.006 in. to 0.018 in. and cuts per revolution (CPR) ranging from 2.5 – 4.5.  For each pitch and CPR combination, loading stiffness …

Niu Fsae Brake Rotor Design & Flywheel-Based Test Stand Development, Cody J. Marko, Austin Coyne, Alexander Boyden

Honors Capstones

This project addresses the need for a reliable and validated brake rotor for the Northern Illinois University Formula SAE vehicle following a prior catastrophic rotor failure within the team. Brake rotors in high-performance applications are subjected to significant thermal and mechanical loads, and inadequate design can lead to failure, posing serious safety risks and limiting vehicle performance. To solve this issue, a new brake rotor was designed alongside a dedicated test stand to both improve braking performance and enable experimental validation. The rotor was evaluated using finite element analysis (FEA), including transient thermal and structural simulations, to predict maximum temperature, …

Engineering Cryogenic Thermal Links And Transport Systems For Conduction-Cooled Superconducting Cavities, Jacob B. Lewis

Mechanical & Aerospace Engineering Theses & Dissertations

The Thomas Jefferson National Accelerator Facility (Jefferson Lab) is currently developing a prototype conduction-cooled 915 MHz SRF cryomodule proposed for industrial use, capable of increasing the energy of an electron beam with 5 mA current by ~ 4 MeV. Two Nb3Sn resonant cavities are under development for this project, in which cryogenic cooling is provided by closed cycle refrigerators (cryocoolers). One cavity utilizes high-purity electroformed copper on the outer surface to provide heat extraction from the cavity, the other relies on high-purity aluminum thermal links. This thesis investigated the thermal conduction pathways between the cavities and cryocooler cold heads, with …

Simulation Of Stress, Deformation, And Vibration In Unlubricated Ball Bearings At Varying Rotational Speeds, Billy Dwiki, Moh. Hartono

Journal of Mechanical Engineering Science and Technology (JMEST)

Bearings are critical components in rotating machinery, and their performance is highly influenced by operational factors such as rotational speed, load, and lubrication. This study aims to analyze the deformation, stress, and dynamic behavior of SAE 52100 bearings under dry operating conditions at various rotational speeds, as well as to propose mitigation strategies for high-speed industrial applications. A finite element simulation was conducted using ANSYS R19.2 to evaluate the total deformation, equivalent elastic strain, Von Mises stress, and vibrational characteristics of a 6204-type SAE 52100 bearing. The simulations were performed across a speed range of 600 to 2000 RPM under …

Numerical Comparative Study Of The Thermal Performance And Load-Bearing Capacity Of Hollow Clay Bricks Used In Construction In Libya, Osama Lawej, Mahmoud Ahmed, Ismael Ehtiwesh

Journal of Sustainable Construction Materials and Technologies

The optimization of structural and thermal performance in building components is a key challenge in sustainable construction, particularly in hot climate regions like Libya. Hollow clay bricks are widely used due to their local availability and affordability; however, their internal geometry is often not optimized for thermal resistance or mechanical integrity. This study addresses this gap by numerically investigating the effect of cavity geometry on the load-bearing capacity and thermal insulation performance of hollow clay bricks. Three configurations were analyzed, including two commercial designs from the Libyan market and a newly proposed arched cavity design. Finite Element Method (FEM) simulations …

Sae Baja Drivetrain Capstone 2024-2025, Leslie Alvarez Cisneros

University Honors Theses

This thesis reviews the 2024-2025 Baja SAE Drivetrain capstone project. The Baja SAE competition mimics real world engineering problems where teams of students design and build off-road vehicles that can handle tough, rough terrain. The objective of this capstone was to design a functional and reliable drivetrain system for the vehicle, within the constraints of a limited budget and the SAE competition guidelines. As part of a 12-member capstone team divided into three subgroups: frame, suspension, and drivetrain. As part of a four person drivetrain team, we picked up where the 2023-2024 team left off by relying on their past …

Computational Modeling Of Torque Arm And Load Cell Interactions In Uta Racing Brake Dynamometer, Anthony A. Aiyedun

2025 Spring Honors Capstone Projects - Archive

The UTA Racing Team is developing a brake dynamometer to measure the coefficients of friction of various brake pads and calipers under controlled conditions. The dynamometer simulates on-track braking scenarios, testing brake pads at temperatures up to 1300ºF and pressures similar to racing environments. Its primary goal is to generate accurate friction vs. temperature graphs for various brake pad and rotor combinations, addressing the need for dedicated testing equipment. This project creates an ANSYS simulation of the torque arm and load cell interaction. The computational model accurately represents the relationship between applied torque and measured load cell force, incorporating precise …

Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau

Honors Scholar Theses

Pulse shape analysis can be used to analyze radiation incident on a semiconductor diode detector. Finite element analysis (FEA) can be used to simulate high purity germanium detectors with user-specified geometry, impurity concentration, and bias voltage. Subsequent streamline calculation can be used to conduct pulse shape analysis for single and multiple site gamma-ray interactions within the detector volume. Cross sections of the detector can be visualized by contour plots of the electric field, drift velocity magnitude, and collection time, as well as t30 and t90 rise-time values.

The Design Of A Bioinspired Impact Mitigation System Towards The Prevention Of Brain Injuries, Bryce H. Reimer

Master’s Theses

Traumatic brain injuries (TBIs), including concussions and chronic traumatic encephalopathy (CTE), remain a major concern across contact sports, military operations, and transportation. Despite advancements in protective equipment, current strategies often fall short in preventing the mechanical conditions that contribute to long-term neurological damage. This thesis presents the design and validation of a bioinspired impact mitigation system modeled after bighorn sheep horn structures, which have evolved to endure high-energy collisions without apparent brain injury.

Using biomimetic principles, the research integrates experimental and computational methods to evaluate how horn-like geometries reduce impact-induced accelerations. A custom drop tower was built to test dynamic …

In-Situ Thermographic Monitoring And Numerical Simulations Of Laser-Foil-Printing Additive Manufacturing, Tunay Turk, Tao Liu, Chia Hung Hung, Richard Billo, Jonghyun Park, Ming C. Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-foil-printing (LFP) is an additive manufacturing (AM) technique offering advantages over traditional powder-based methods. A deeper understanding of the melt pool dynamics is crucial for optimizing process parameters and achieving high-quality builds. This paper presents a combined approach utilizing numerical simulations and in-situ thermographic monitoring to investigate the relationship between scanning strategies, melt pool dimensions, and cooling rate in LFP. The numerical simulations are employed to predict melt pool behavior using a time-dependent thermal finite element analysis (FEA). Results demonstrate that the simulations accurately predict melt pool dimensions, showing strong agreement with experimental data. Simultaneously, real-time melt pool dynamics were …

Design And Manufacturing Of Multifunctional Piezoelectric Composites, Huan Zhao

Dartmouth College Ph.D Dissertations

Piezoelectric materials possess a unique ability to convert mechanical energy into electrical signals and have broad industrial applications. However, monolithic piezoelectric materials such as piezoceramics and piezopolymers often suffer from inherent trade-offs among mechanical strength, elasticity, and durability. Piezoelectric composites, typically consisting of a polymer matrix with ceramic reinforcements, offer a solution by combining the advantages of each constituent. Nevertheless, maintaining stable mechanical performance in high-temperature environments remains a significant challenge as conventional polymer matrices usually experience structural degradation.

In this thesis, a novel piezoelectric composite is developed using a preceramic polymer (PCP) matrix with barium titanate (BTO) inclusions. PCPs …

Pre-Programmable Directional Stiffness In Continuum Robotic Arms: Effects Of Truss Configurations, Mostafa Abdelaziz, Zahy Elgendy, Mahmoud Magdy

Mechanical Engineering

This paper investigates the implementation of trussed designs in modular tendon-driven continuum arms (CAs) to address stiffness and stability limitations while maintaining adaptability. Various truss configurations— Single-Level, Combined-Level, and Alternated trusses—were analyzed using Finite Element Analysis (FEA) to evaluate their impact on flexural and axial stiffness under realistic loading conditions. Results demonstrate that truss placement significantly influences performance, with bottom-level trusses improving flexural stiffness by up to 33%, middle-level trusses enhancing axial stiffness by 43%. Further, Combined-Level configurations provide superior overall stiffness, with MiddleBottom trusses achieving a 66.5% improvement in flexural stiffness and a 70.9% increase in axial stiffness, while …

Advancements In Aerial Vehicle Platforms: A Guide For Design, Validation, And Implementation Of 3d Printed Drones, Alan Salvador Urteaga

Theses and Dissertations

Additive manufacturing methods have revolutionized the way products are designed and developed through a product's entire design life cycle. This is in part correlated with the nature of additive manufacturing methods that differentiate them from traditional methods. Some of the benefits of additive manufacturing methods include customizability, rapid prototyping, the production of complex design geometry, and embedded assembly manufacturing. Unmanned aerial vehicles have been on the rise for various military, commercial, or personal applications. The focus of this study is to provide detailed instructions on how to engineer a viable drone design that is impact-resistant, modular, and customizable. This study …

Process Modeling Of Composites For Automated Fiber Placement, Von Clyde Jamora

Mechanical & Aerospace Engineering Theses & Dissertations

Fiber-reinforced composites are available in various material systems, each requiring specific manufacturing techniques to exploit their unique properties fully. Systems such as woven fabrics and preimpregnated fibers employ distinctive methods to harness these properties effectively. For instance, non-crimp fabrics (NCF) use high-pressure resin transfer molding and prepregs, like IM7-8552, use manufacturing method called automated fiber placement (AFP). However, these manufacturing processes often introduce deposition features that can evolve into defects. Their occurrence and impact on morphology must be predicted using experimentally informed finite element models. The research began with compaction experiments on NCF fabric, leading to the development of a …

Design, Prototyping, And Characterization Of A Micro-Force Sensor Intended For Tissue Assessment In Confined Spaces, Shashank S. Kumat, Panos S. Shiakolas

Open Initiatives Grant Funded Publications-Archive

The quantitative characterization of soft tissue viscoelastic properties can aid in disease prognosis and diagnosis. Existing technologies present challenges to measuring localized in vivo tissue relaxation data while meeting load and geometric constraints. This research presents the design, prototype, and characterization of a micro-force sensor that could enable better access to confined spaces of the human body. The novel design of the uniaxial micro-force sensor has an external diameter of less than or equal to 3.5 mm and 1 N load capacity for transurethral palpation of the bladder interior wall. The conceptual design of the micro-force sensor and a finite …

Prediction Of Defects In Deep Drawn Rectangular Parts Using Finite Element Analysis (Fea) And Response Surface Methodology (Rsm), Mustafa M. Semman Eng., Mostafa Shazly, Mohamed H. Gadallah, Tamer Adel Mohamed, Abdallah S. Wifi

Mechanical Engineering

Abstract. Deep drawing defects such as thinning and earing present challenges to sheet metal forming industry while designers tend to favour the usage of new materials and production processes. The present work introduces an integrated approach using Design of Experiment, FEA experimentation and RSM to study the effect of deep drawing process parameters and resulting defects associated with sheet metal forming processes such as thinning and earing particularly in deep drawing of non-circular parts. The Design of Experiment (DoE) is used to generate a series of experiments for different process parameters in deep drawn rectangular products which are then simulated …

A Computational Framework For Predicting Cell-Specific Nucleo-Cytoskeletal Forces, Madison Leigh Goldfeldt

Boise State University Theses and Dissertations

Understanding the influence of mechanical forces on cell function and fate is crucial in unraveling the intricate mechanisms that govern cellular behavior. The cytoskeleton, a dynamic network of protein filaments, plays a pivotal role in sensing and transmitting mechanical cues within cells. The nucleus relies on cytoskeletal mechanical input through nuclear envelope adaptor proteins to sense external stimuli and respond by regulating intra-nuclear chromatin organization. This research provides a means for examining the interplay between mechanical forces and the cytoskeleton in regulating various cellular processes, including cell adhesion, migration, division, and differentiation. Through studying and simulating the cellular response to …

A Manufacturing-To-Response Pathway For Manufacturing Optimization Of Carbon Fiber Reinforced Polymer Composite Structures, Madhura Limaye

All Dissertations

Over the past decade, there has been an increased adoption of thermoplastic and thermoset based continuous carbon fiber reinforced polymer (CFRP) composites for structural applications in several industries. Among the different manufacturing methods, thermoforming process for thermoplastic based continuous CFRP’s offer a major advantage in reducing cycle times for large scale productions. Similarly, out-of-autoclave curing process for thermoset based continuous CFRP’s using heated tooling enables production of large composite structures. However, these manufacturing processes can have a significant impact on the structural performance of parts by inducing undesirable effects. These effects include inhomogeneous fiber orientations, thickness variations, and residual stresses …

Effect Of Resin Bleed Out On Compaction Behavior Of The Fiber Tow Gap Region During Automated Fiber Placement Manufacturing, Von Clyde Jamora, Virginia Rauch, Sergii G. Kravchenko, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

Automated fiber placement is a state-of-the-art manufacturing method which allows for precise control over layup design. However, AFP results in irregular morphology due to fiber tow deposition induced features such as tow gaps and overlaps. Factors such as the squeeze flow and resin bleed out, combined with large non-linear deformation, lead to morphological variability. To understand these complex interacting phenomena, a coupled multiphysics finite element framework was developed to simulate the compaction behavior around fiber tow gap regions, which consists of coupled chemo-rheological and flow-compaction analysis. The compaction analysis incorporated a visco-hyperelastic constitutive model with anisotropic tensorial prepreg viscosity, which …

Mechanical Characterization Of Functionally Graded M300 Maraging Steel Cellular Structures, Bradley Jay Sampson

Theses and Dissertations

Traditional methods for increasing the energy absorption of a structure involve using a stronger material or increasing the volume of the structure, resulting in a higher cost or additional weight. Additive manufacturing (AM) can be used to maximize the energy absorption of materials with the ability to create complex geometries such as cellular structures. Previous work has shown that the energy absorption of additively manufactured parts can be improved through functionally graded cellular structures; however, this strategy has not been applied to ultra-high strength steel materials. This work characterizes the effect of multiple functional-grading strategies (e.g. uniform, rod-graded, size-graded) on …

Microscale Modelling Of Lightning Damage In Fibre-Reinforced Composites, Scott L. J. Millen, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

In this work, three-dimensional (3D) finite element simulations were undertaken to study the effects of lightning strikes on the microscale behaviour of continuous fibre-reinforced composite materials and to predict and understand complex lightning damage mechanisms. This approach is different from the conventional mesoscale or macroscale level of analysis, that predicts the overall lightning damage in composite laminates, thus providing better understanding of lightning-induced thermo-mechanical damage at a fundamental level. Micromechanical representative volume element (RVE) models of a UD composite laminate were created with circular carbon fibres randomly distributed in an epoxy matrix. The effects of various grounding conditions (one-, two-, …

Design Of An Innovative Hybrid Sandwich Protective Device For Offshore Structures, Hozhabr Mozafari, Fabio Distefano, Gabriella Epasto, Linxia Gu, Emanoil Linul, Vincenzo Crupi

Department of Mechanical and Materials Engineering: Faculty Publications

Lightweight foam sandwich structures have excellent energy absorption capacity, combined with good mechanical properties and low density. The main goal of this study is to test the application of an innovative hybrid sandwich protective device in an offshore wind turbine (OWT). The results are useful for offshore structure applications. Different lightweight materials (aluminum foam, agglomerated cork, and polyurethane foam) were investigated using experimental tests and numerical simulations. Closed-cell aluminum foam showed the best performance in terms of the energy absorption capacity during an impact. As such, a Metallic Foam Shell (MFS) device was proposed for the fender of offshore wind …

Comparative Study Of Tapered Versus Conventional Cylindrical Balloon For Stent Implantation In Stenotic Tapered Artery, Xiang Shen, Jiabao Jiang, Hongfei Zhu, Kaikai Lu, Pengfei Dong, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The natural tapering of coronary arteries often creates a dilemma for optimal balloon sizing during stenting. The influence of different balloon types, namely, a tapered balloon and a conventional cylindrical balloon, on the mechanical performance of the stent as well as arterial mechanics was investigated via the finite element method. Stent free-expansion and stent deployment in a stenotic tapered artery were investigated numerically. The biomechanical behavior of the two balloon types was compared in terms of stent foreshortening, stent deformation, stent stress distribution, and arterial wall stress distribution. Results indicate that balloon types affect the transient behavior of the stent …

The Effect Of Soft Tissue And Bone Morphology On The Stresses In The Foot And Ankle, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

The foot and ankle interface with the ground, thus they absorb reaction forces and initiate load distribution through the body. The plantar fascia (PF) is a flexible structure that absorbs reaction forces and distributes loading across the foot. It is frequently a source of foot pain especially when people have plantar fasciitis and/or diabetes mellitus. Finite element (FE) models of the foot and ankle were created to examine the function however, the plantar fascia is frequently modeled as a 1D tension only spring, which does not represent variations caused by injury and/or disease.

As models move toward being patient specific, …

Computational Mechanics Implementation Of Performance Based Testing In Massive Concrete Structures, Gabriel Y. Riveros

ME 4233/6233 Fundamentals of FEA

Most of the nation’s critical water resource infrastructures are near or have exceeded their design lives. Consequently, there is a huge need for the development of assessment procedures that will change the way dams are maintained and operated with the intent of extending the service life. This is crucial for ensuring the safety and security of our nation’s public services. The combination of advanced computational mechanics and performance based testing (PBT) methods can be used to investigate the existing conditions of large concrete structures.

Performance based testing (PBT) is a new and innovative non-destructive testing technique that we are implementing …

Electromagnetic Modeling Of A Wind Tunnel Magnetic Suspension And Balance System, Desiree Driver

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnels are used to study forces and moments acting on an aerodynamic body. While most results involve some interference from the mechanical supports used to hold the model, a Magnetic Suspension and Balance System (MSBS) is void of these interferences and presents an ideal test scenario. To further investigate the feasibility of dynamic stability testing at supersonic speeds using a MSBS, a preliminary design idea is currently being developed using an existing MSBS in a subsonic wind tunnel. This review focuses on the development of a mathematical model to more accurately portray the capabilities of the 6 inch Massachusetts …

Method Of Embedded Imperfections For The Direct Simulation Of Deformation Instabilities In Film-Substrate Structures, Siavash Nikravesh Kazeroni

Mechanical Engineering ETDs

In this dissertation, a novel finite-element methodology called “embedded imperfections” is proposed and employed for computationally simulating various types of deformation instabilities observed in film-substrate structures subjected to mechanical loading. The approach involves the incorporation of elements having distinctive material properties within the film-substrate interface. One can interpret this practice as a deliberate distribution of material defects within the numerical model. It has been shown that embedded imperfections not only can trigger the onset of instability, but also can lead to “direct” simulation of deformation instability problems in that primary and subsequent instability modes can all be captured in a …

Thermoforming Process Effects On Structural Performance Of Carbon Fiber Reinforced Thermoplastic Composite Parts Through A Manufacturing To Response Pathway, Madhura Limaye, Sai Aditya Pradeep, Anmol Kothari, Sushil Savla, Akshat Agha, Srikanth Pilla, Gang Li

Publications

Thermoforming process of thermoplastic-based continuous CFRP's offer a major advantage in reducing cycle times for large-scale productions, but it can also have a significant impact on the structural performance of the parts by inducing undesirable effects. This necessitates the development of an optimal manufacturing process that minimizes the introduction of undesirable factors in the structure and thereby achieves the targeted mechanical performance. This can be done by first establishing a relationship between the manufacturing process and mechanical performance and successively optimizing it to achieve the desired targets. The current study focuses on the former part, where a manufacturing-to-response (MTR) pathway …

Structural And Hemodynamic Analysis Of Transcatheter Aortic Valves, Dong Qiu

Electronic Theses and Dissertations

The transcatheter aortic valve replacement (TAVR) procedure has become a well-established procedure for high, intermediate-risk, and low-risk patients. However, there is limited clinical data on the TAV's long-term durability, unlike SAV devices. Computational simulations can be an alternative way to evaluate the TAV devices. This dissertation aims to conduct structural and hemodynamic analyses on the TAV devices under different conditions using computational simulation approaches.

Initially, the impact of the bicuspid aortic valve on the TAV devices was evaluated. The result indicated that the CoreValve-like supra-annular self-expandable device was likely to have increased stress and strain on the leaflet when it …