Acoustics, Dynamics, and Controls Commons^™

Me3329 Modular Phonograph Gearbox, Garrett Andrik Leighton, Preston Robert Hupe, Gavin Carter Ebner, Andrew Renato Reyes

Mechanical Engineering

The Mechanical Engineering Department at California Polytechnic State University, San Luis Obispo (Cal Poly), seeks to develop a laboratory tool allowing students to reinforce concepts of gears for Mechanical Systems Design (ME329). Some current laboratories do not provide students with hands-on interaction, and the department lacks equipment and documentation to support a standardized lab. With ME329 expanding from ten to fifteen weeks, there is an opportunity to create a physical gearbox design lab allowing students to reinforce lecture material in engaging ways, while standardizing student learning. This senior project is presented and sponsored by Professor Alan Zhang. It will be …

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 …

Versatile Exoskeleton Control Paradigms For Agile Human Locomotion: Task-Agnostic And Stability-Augmented Assistance, Miao Yu

All Dissertations

Lower-limb exoskeletons have shown great potential for assisting human locomotion, but designing controllers that provide assistance across diverse locomotor tasks and under external perturbations remains a major challenge. Many existing controllers for steady-state walking rely on pre-defined reference trajectories, which constrain voluntary human motion and limit adaptability across tasks. Moreover, they usually assume stable walking, while their performance under unstable conditions remains largely unexplored. In addition, existing gait stability augmentation controllers are often reactive rather than proactive to unstable conditions. In this dissertation, we propose control frameworks that preserve voluntary human motion while addressing two major challenges: providing task-agnostic assistance …

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 …

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

Mechanical and Materials Engineering Faculty Publications

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

Data-Driven Constrained Control, Ali Kashani

Mechanical Engineering ETDs

Ensuring safety is a fundamental challenge. Traditional methods often rely on precise mathematical models, which are difficult, impractical, or costly to obtain for real-world systems with complex, nonlinear dynamics. This dissertation develops direct data-driven control approaches that enable safe and efficient operation of nonlinear systems without requiring explicit models or performing system identification. This effort leverages machine learning, optimization, and control theory to bridge theoretical rigor and practical applicability. Deterministic guarantees are provided based on the Lipschitz continuity of the system, and probabilistic guarantees through scenario optimization. The computation of safe sets is performed using one-shot approaches with broad neural …

Capacitive Sensors With Ultra-Small Capacitance For Smart Measurement And Control Systems, Rustam Baratov, Farrux Jabbor O'G'Li Ko'charov

Chemical Technology, Control and Management

This article discusses methods of low capacitance measurement of capacitive sensors. The results of the study of the amplitude-frequency (AF) and phase-frequency (PF) response of measurement circuits of capacitive sensors for low capacitances measurement, consisting of RC - differentiating elements are presented. The input and output parameters of the differentiating circuit and the complex transfer function are analyzed. The research results show that low capacitances measurement by measuring the rectangular pulses duration is the most effective measurement method.

A Computational Investigation Of Wood Selection For Acoustic Guitar, Jonah Osterhus

Senior Honors Theses

The acoustic guitar is a stringed instrument, often made of wood, that transduces vibrational energy of steel strings into coupled vibrations of the wood and acoustic pressure waves in the air. Variations in wood selection and instrument geometry have been shown to affect the timbre of the acoustic guitar. Computational methods were utilized to investigate the impact of material properties on acoustic performance. Sitka spruce was deemed the most suitable wood for guitar soundboards due to its acoustic characteristics, strength, and uniform aesthetic. Mahogany was deemed to be the best wood for the back and sides of the guitar body …

Numerical Investigation Of Supersonic Flow Over A Wedge By Solving 2d Euler Equations Utilizing The Steger–Warming Flux Vector Splitting (Fvs) Scheme, Mitch Wolff, Hashim H. Abada, Hussein Awad Kurdi Awad Kurdi Saad

Mechanical and Materials Engineering Faculty Publications

Supersonic flow over a half-angle wedge (θ = 15°) with an upstream Mach number of 2.0 was investigated using 2D Euler equations where sea level conditions were considered. The investigation employed the Steger–Warming flux vector splitting (FVS) method executed in MATLAB 9.13.0 (R2022b) software. The study involved a meticulous comparison between theoretical calculations and numerical results. Particularly, the research emphasized the angle of oblique shock and downstream flow properties. A substantial iteration count of 2000 iteratively refined the outcomes, underscoring the role of advanced computational resources. Validation and comparative assessment were conducted to elucidate the superiority of the Steger–Warming flux …

Numerical Simulation Of Laser Induced Elastic Waves In Response To Short And Ultrashort Laser Pulses., Alireza Zarei

All Dissertations

In an era of intensified market competition, the demand for cost-effective, high-quality, high-performance, and reliable products continues to rise. Meeting this demand necessitates the mass production of premium products through the integration of cutting-edge technologies and advanced materials while ensuring their integrity and safety. In this context, Nondestructive Testing (NDT) techniques emerge as indispensable tools for guaranteeing the integrity, reliability, and safety of products across diverse industries.

Various NDT techniques, including ultrasonic testing, computed tomography, thermography, and acoustic emissions, have long served as cornerstones for inspecting materials and structures. Among these, ultrasonic testing stands out as the most prevalent method, …

Long-Term Simulation Of Stem Cell Mechanobiology, Manoochehr Rabiei

Mechanical and Aerospace Engineering Dissertations - Archive

An accurate representation of cellular mechanobiology necessitates the inclusion of subcellular elements characterized by minute masses and dimensions. These minute objects yield multiscale dynamic models with disproportionate terms, which require inordinate amounts of computational time to simulate. The computational requirements limit the time span of the simulation to time histories shorter than one second, even when employing supercomputers. This work presents a high-speed approach to simulating the mechanobiology of stem cells. The proposed approach separates the computational time from the size, and distribution, of masses of the subcellular elements, enabling the simulation of weeks-long cellular processes within hours on a …

External Direct Sum Invariant Subspace And Decomposition Of Coupled Differential-Difference Equations, Keqin Gu, Huan Phan-Van

SIUE Faculty Research, Scholarship, and Creative Activity

This article discusses the invariant subspaces that are restricted to be external direct sums. Some existence conditions are presented that facilitate finding such invariant subspaces. This problem is related to the decomposition of coupled differential-difference equations, leading to the possibility of lowering the dimensions of coupled differential-difference equations. As has been well documented, lowering the dimension of coupled differential-difference equations can drastically reduce the computational time needed in stability analysis when a complete quadratic Lyapunov-Krasovskii functional is used. Most known ad hoc methods of reducing the order are special cases of this formulation.

Structured Invariant Subspace And Decomposition Of Systems With Time Delays And Uncertainties, Huan Phan-Van, Keqin Gu

SIUE Faculty Research, Scholarship, and Creative Activity

This article discusses invariant subspaces of a matrix with a given partition structure. The existence of a nontrivial structured invariant subspace is equivalent to the possibility of decomposing the associated system with multiple feedback blocks such that the feedback operators are subject to a given constraint. The formulation is especially useful in the stability analysis of time-delay systems using the Lyapunov-Krasovskii functional approach where computational efficiency is essential in order to achieve accuracy for large scale systems. The set of all structured invariant subspaces are obtained (thus all possible decompositions are obtained as a result) for the coupled differential-difference equations …

Ultrasonic Non-Destructive Evaluation Of Additively Manufactured Polymer-Ceramic Composites, Christian Alexander Ruiz

Open Access Theses & Dissertations

Digital light processing (DLP) is an attractive additive manufacturing technique due to its ability to create ceramic parts with complex geometries. DLP uses ultraviolet light to polymerize a slurry comprised of ceramic powder and photosensitive resin in layers to create solid parts. Printing parameters such as light intensity and exposure time are critical when producing these parts. Improper parameters can lead to over or under-curing, adversely impacting print quality and strength. Samples were printed at varying layer exposure times and then tested using ultrasonics to determine the degree of conversion. Additionally, ultrasonics were used as a non-destructive technique to obtain …

Mechanical Design Of A Microwave Imaging Device For Breast Cancer Detection In Mri Scanners, Grace M. Player

Dartmouth College Master’s Theses

This project seeks to develop an updated version of a microwave imaging device for use in conjunction with breast MRI, improving upon existing technology and developing novel concepts for the device. It posits three primary redesign targets for updating the previous system: resizing the system height, making the device more iteration- friendly, and improving the overall manufacturability of the device by replacing custom components with commercially available alternatives. All three of these redesign targets are met in the new design, V2.0. The height is reduced by reducing antenna travel and height, embedding some components, and shortening the tank wall, resulting …

Multi-Robot Symbolic Task And Motion Planning Leveraging Human Trust Models: Theory And Applications, Huanfei Zheng

All Dissertations

Multi-robot systems (MRS) can accomplish more complex tasks with two or more robots and have produced a broad set of applications. The presence of a human operator in an MRS can guarantee the safety of the task performing, but the human operators can be subject to heavier stress and cognitive workload in collaboration with the MRS than the single robot. It is significant for the MRS to have the provable correct task and motion planning solution for a complex task. That can reduce the human workload during supervising the task and improve the reliability of human-MRS collaboration. This dissertation relies …

Bbt Acoustic Alternative Top Bracing Cadd Data Set-Norev-2022jun28, Bill Hemphill

STEM Guitar Project’s BBT Acoustic Kit

This electronic document file set consists of an overview presentation (PDF-formatted) file and companion video (MP4) and CADD files (DWG & DXF) for laser cutting the ETSU-developed alternate top bracing designs and marking templates for the STEM Guitar Project’s BBT (OM-sized) standard acoustic guitar kit. The three (3) alternative BBT top bracing designs in this release are
(a) a one-piece base for the standard kit's (Martin-style) bracing,
(b) 277 Ladder-style bracing, and
(c) an X-braced fan-style bracing similar to traditional European or so-called 'classical' acoustic guitars.

The CADD data set for each of the three (3) top bracing designs includes …

Bbt Side Mold Assy, Bill Hemphill

STEM Guitar Project’s BBT Acoustic Kit

This electronic document file set covers the design and fabrication information of the ETSU Guitar Building Project’s BBT (OM-sized) Side Mold Assy for use with the STEM Guitar Project’s standard acoustic guitar kit. The extended 'as built' data set contains an overview file and companion video, the 'parent' CADD drawing, CADD data for laser etching and cutting a drill &/or layout template, CADD drawings in AutoCAD .DWG and .DXF R12 formats of the centerline tool paths for creating the mold assembly pieces on an AXYZ CNC router, and support documentation for CAM applications including router bit specifications, feeds, speed, multi-pass …

Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter

Materials Engineering

Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …

Investigation Of Topological Phonons In Acoustic Metamaterials, Wenting Cheng

Dissertations

Topological acoustics is a recent and intense area of research. It merges the knowledge of mathematical topology, condensed matter physics, and acoustics. At the same time, it has been pointed out that quasiperiodicity can greatly enhance the periodic table of topological systems. Because quasiperiodic patterns have an intrinsic global degree of freedom, which exists in the topological space called the hull of a pattern, where the shape traced in this topological space is called the phason. The hull augments the physical space, which opens a door to the physics of the integer quantum Hall effect (IQHE) in arbitrary dimensions. In …

Challenges And Signal Processing Of High Strain Rate Mechanical Testing, Barae Lamdini

Theses and Dissertations

Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of …

Grinding And Super-Finishing Test Machine Project, Michael Simon

Williams Honors College, Honors Research Projects

A research project in The University of Akron to study grinding and super-finishing of silicon nitride ceramic was initiated by Dr. Siamak Farhad and sponsored by the Timken Company, with the assistance of undergraduate students Michael Simon, Ryan Hosso and Mathew Rozmajzl. The study required analysis of forces and scratches generated during grinding processes of silicon nitride samples. A testing assembly was designed and constructed to record the forces generated during grinding and super-finishing of silicon nitride samples in a computer-numerical-control machine. Silicon nitride samples were subjected to desired grinding and super-finishing operations and all forces generated during the process …

A Single-Stage Passive Vibration Isolation System For Scanning Tunneling Microscopy, Toan T. Le

Master's Theses

Scanning Tunneling Microscopy (STM) uses quantum tunneling effect to study the surfaces of materials on an atomic scale. Since the probe of the microscope is on the order of nanometers away from the surface, the device is prone to noises due to vibrations from the surroundings. To minimize the random noises and floor vibrations, passive vibration isolation is a commonly used technique due to its low cost and simpler design compared to active vibration isolation, especially when the entire vibration isolation system (VIS) stays inside an Ultra High Vacuum (UHV) environment. This research aims to analyze and build a single-stage …

Entertainment 721, Mark Hendricks, Noah John, Jadon Vanyo, Chelsea Payne

Williams Honors College, Honors Research Projects

The goal of this project was to design a luxury, aesthetically pleasing entertainment system with a TV lift mechanism that could be remote controlled. The design would also include a cooling cabinet for gaming systems, a remote locking system, and additional storage. Using a morphological chart and weighted decision matrix for each subsystem key features were determined to be included in the design. Several performance benchmarks were determined to accomplish the team’s design. Almost every benchmark was successful in the build of the first prototype. Several heat calculations and FEA analyses were performed on the system to ensure the success …

Stability Analysis, Dynamic Modeling, And Kinematic Analysis Of Hydraulically Amplified Dielectric Elastomer Actuators And Robot Manipulators, Amir Hosein Zamanian

Mechanical Engineering Research Theses and Dissertations

In this dissertation, we have proposed a new dielectric elastomer actuator design and model that couples electrostatics, fluid mechanics, linear and nonlinear elastic deformations. The internal hydraulic pressure can amplify the structural deformation generated by induced electrostatic forces (Maxwell pressure), given the name of this class of actuators, hydraulically amplified dielectric elastomer actuators (HADEAs).

First, we developed novel lumped-parameter models (LPMs) using linear and hyper-elastic material models and second compared the LPM results with finite element analysis in quasi-static simulations. We analytically expressed the conditions for the snap-through instability in the HADEA, which appears after exceeding a certain voltage applied …

Hybrid Non-Destructive Assessment For Flow Induced Vibration Piping Systems Using Coupled Fluid-Structure Interaction, Keen Kuan Kong

Student Works (2020-2029)

Pipelines and piping systems are of great importance in many industries such as water supply, petroleum and petrochemicals and nuclear power generation. They provide transport for high-velocity pressurized fluids operating under time-varying conditions. They are required to operate non-stop for a schedule of 24 hours a day, 7 days a week. Piping vibration failures have been one of the major causes of downtime, fires and explosions in industrial plant over the past 30 years. Failure of piping systems can have disastrous effects, leading to injuries and fatalities as well as to substantial cost to industry and the environment. Flow-induced vibration …

Kinematic Analysis Of Forehand Drop Shot And Long Shot Services In Table Tennis, Ibrahim Norzuria

Student Works (2020-2029)

Table tennis is one of the most widely played sports in the world. A frequent hand movement is compulsory to execute stroke than other limbs, especially the projection of racket and ball speeds,which can help to improve players’ performance. Until now, research on table tennis serving is limited. Service was assumed important in table tennis because the effective serve may allow the serving player to have advantage and control over the game. The 3D dynamic analysis is the appropriate method to analyze a sport activity such as table tennis. Therefore, the aim of research was to determine the kinematic involved …

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Dynamic Loading Experimentation And Surface Imaging Of Pressure Vessel Loadcell Fractures, Austin T. Sumner

Honors College Theses

Pressure vessels are very common pieces of equipment in industry and they are used for a variety of applications. It is standard in industry to rest pressure vessels on load cells. For some special cases, the pressure vessels are rested on load cells instead of solid foundation. Pressure vessels and their loadcells are generally designed for static environmental conditions and loading and tend to experience adverse effects when exposed to dynamic environments, such as hurricanes and earthquakes. These adverse-loading conditions cause vibrations and asymmetrical loading on the load cells, which can concurrently cause unexpected failure. This research investigates the effects …

Investigation Of Fundamental Principles Of Rigid Body Impact Mechanics, Khalid Alluhydan

Mechanical Engineering Research Theses and Dissertations

In impact mechanics, the collision between two or more bodies is a common, yet a very challenging problem. Producing analytical solutions that can predict the post-collision motion of the colliding bodies require consistent modeling of the dynamics of the colliding bodies. This dissertation presents a new method for solving the two and multibody impact problems that can be used to predict the post-collision motion of the colliding bodies. Also, we solve the rigid body collision problem of planar kinematic chains with multiple contacts with external surfaces.

In the first part of this dissertation, we study planar collisions of Balls and …