Mechanical Engineering Commons^™

Design And Assembly Of A Variable Buoyancy System For An Autonomous Underwater Vehicle, Evan Brown

Master's Theses

Autonomous underwater vehicles (AUVs) play a vital role in the surveillance and mapping of our oceans, often requiring extensive travel in extreme environments. These data-gathering missions benefit from extended durations, making the minimization of power consumption a key consideration in AUV design. One effective strategy to reduce energy use in AUVs is to implement a variable buoyancy system (VBS) for depth control. The purpose of this work is to design, develop, test, and model a variable buoyancy system to enhance the efficiency and capabilities of a high-speed, long-range AUV.

After evaluating various VBS designs, a piston-cylinder buoyancy system was selected …

Solar Farm, Parker Folsom, Jon Copeland, Julia Fay, Aiden Taylor

Mechanical Engineering

This senior project focused on creating a portable single-axis solar follower. The purpose of this solar follower is to allow for single-axis tracking of the sun at various points on our sponsor's property to gather information on solar power production. This data will be utilized to locate future sites for a utility-scale solar farm.

The final design of the solar follower comprises four subsystems: two legs, the frame, and the panel assembly. This modular design allows for portability and adjustability on challenging terrain. Following the design stage, our team purchased and manufactured all of the necessary components. All manufacturing work …

Bird Trail Stairway Access Replacement, Mackenzie Wright, William Spellman, Nicholas Buccino, Jack Long

Mechanical Engineering

Dana Adobe & Cultural Center, a non-profit organization in Nipomo, California, seeks to restore access to the Bird Trail located on their site. This project aims to design and manufacture a replacement stairway for safe creek bed crossing on the trail. Within this document, we have detailed our system design, function, and justification for our design. The procurement, manufacturing, and assembly plan have been outlined along with tests we completed.

One of the most important functions of our design is for the structure to be retractable so that it can be removed from the creek bed when needed. To address …

Scitechatorium Exhibit, Adam Khan, Cole Busch, Logan Femling, Alan Onuma

Mechanical Engineering

This document outlines the final stages of development and analysis of our interactive children’s exhibit for the Bellevue-Santa Fe Charter School’s SciTechatorium. We will showcase the final form of our ball and track display, giving a detailed look at each component and subsystem.

To describe how our final prototype will be built we have included a detailed manufacturing summary for our design. Our models have been designed with manufacturability in mind, and we have outlined which processes were used to produce all our parts.

There are also detailed descriptions of testing that were conducted to verify the performance of the …

Non-Linear Modeling Of Hysteresis In Piezoelectric Actuated Cantilever Beam Using The Bouc-Wen Model, Andrew Donald Maas

Master's Theses

Piezoelectric actuators frequently exhibit a time-dependent behavioral phenomenon known as hysteresis, resulting in a lag in the deformation of the actuator compared to linear models. The presence of hysteresis complicates control systems involving piezoelectric actuators. However, traditional modeling methods for piezoelectric actuated smart structures often treat the piezoelectric patches as linear actuators without considering hysteresis, leading to suboptimal controller performance.

This thesis aims to establish a comprehensive model by integrating the Euler-Bernoulli beam bending model with the hysteresis dynamics induced by two opposing piezoelectric patches attached to a beam. A model expansion method is employed to transform the partial differential …

Cal Poly Fluid Power Vehicle Challenge 2024, J. Mason Gray, Ryan D'Amour, Alberto Acho Lopez, Christian Ferrandino, Johnathan Dietz

Mechanical Engineering

In this Final Design Review, the Cal Poly Fluid Power Vehicle Team competed in Norgren’s 2024 Fluid Power Vehicle Challenge. The design need of the competition was for college teams to compete with human-powered, hydraulic-driven vehicles in an endurance race, a sprint race, an efficiency race, and a regenerative power race. The competition need was to design a vehicle to win in as many races as possible, achieving the highest overall score and winning the competition. With a design emphasis on the endurance and sprint race, the Cal Poly team designed a fluid power system that fastened to a purchased …

Removable Equipment Climate Canopy, Jessica Perez, Sabine Heid, Zil Panchal, Anali Salazar

Mechanical Engineering

The Climate Canopy Project has developed an improved solution for creating an adjustable shade mechanism tailored specifically for users of pull walkers. Through extensive research, goal setting, and a comprehensive framework our project has examined the challenges faced by individuals who rely on walkers for mobility. Our stakeholder requires a product that is lightweight, removable, and compact. This study dissected the designs of previous products on the market and aimed to build a product that aligns with our sponsor’s desires.

This report presents the main goals for the design and manufacturing process, along with key design features utilized to produce …

Development Of Electrical Impedance Tomography Data Acquisition System And Deep Learning-Based Reconstruction Algorithms For Spatial Damage Detection, Damond Michael Li

Master's Theses

Electrical impedance tomography (EIT) is a non-destructive, non-invasive, and non-radioactive imaging technique used for reconstructing the internal conductivity distribution of a sensing domain. Performing EIT often requires large, stationary benchtop equipment that can be expensive and impractical. Other researchers have attempted to make portable EIT systems, but they all rely on external computation for image reconstruction/data analysis. This study outlines the development of a low-cost, portable, and wireless EIT data acquisition (DAQ) system that is capable of independently performing image reconstructions on-board. With the proposed system, EIT can be performed on carbon fiber reinforced polymers to spatially locate damages. Since …

Exhaust Manifold Pressure As Engine Tuning Parameter, Kieran Truth Cunningham, Adam Sullivan Mathews, Connor Richard Smullen

Mechanical Engineering

In this project, the exhaust manifold absolute pressure (EMAP) of a 1986 Toyota Corolla was analyzed across a variety of load cases and was compared with the mass air flow (MAF) of the intake, simultaneously. Correlations were found in the trends of EMAP and MAF sensor readings that may prove helpful in tuning engines that have difficulty in accommodating a MAF sensor. These correlations were found in areas of the powerband where aftermarket tuned engines typically have poor airflow sensing. An equation was developed to spoof MAF input using EMAP and other engine operating parameters.

Pitot Tube Test Bench, Jesus Perez, Zachary Owen, Adrian Lopez

Mechanical Engineering

This Final Design Review documents the senior design project carried out by a team of Mechanical Engineering students attending California Polytechnic State University, San Luis Obispo for Roger Benham, and his company Leak Control Services Inc. The requirement was to design, build, and validate the performance of a test fixture that quantifies the performance characteristics of flow rate and pressure drop of different pitot tube designs to be used in a chemical dispensing application for Mr. Benham. This document includes relevant background research on the need for the fixture as well as relevant technical research. This document also contains objectives …

Asme Electric-Human Powered Vehicle (Ehpv) Project, George Bernat, Roman Bradley, Casey Pickett, Paul Mansfield

Mechanical Engineering

This report documents the collaborative efforts of the senior design team and the Cal Poly Human Powered Vehicles Club in creating an electric-assisted human powered vehicle tailored for participation in ASME's e-HPV Spring 2024 competition. Delving into a comprehensive account of the project's lifecycle, the report outlines the iterative stages of ideation and design, the manufacturing processes, testing , and subsequent refinements undertaken by the team. Additionally, it provides analysis of the project management strategies employed, as well as an overall appraisal of successes, setbacks, and areas improvement. As a result of the project, the vehicle (shown below) was successfully …

Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain

Master's Theses

Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …

Efficacy Of Passive Ventilation With High Exhaust Demands: A Case Study Of Cal Poly Sst, Siddarth Bokka

Construction Management

The Simpson Strong Tie Demonstration Laboratory serves as a multipurpose space allowing students at the College of Architecture and Environmental Design at California Polytechnic State University to build full scale construction projects. The building features a material storage area, a high bay for construction of full-scale projects, and a mezzanine level that houses digital fabrication equipment. However, the building was never designed to house the specific equipment currently installed on the mezzanine and ventilate the exhaust fumes from them. Rather, the building relies on passive natural ventilation that is likely ineffective at properly exhausting hazardous fumes, resulting in complaints from …

Cnc Retrofits, Fabian Samano, Murat Askin, Daniel Lonczak, Zane Campise

Mechanical Engineering

The Boxford CNC Lathe is a machine used for educational purposes. The goal of the CNC Retrofits project is to improve the Boxford MT2’s performance and functionality to enable Mr. Lonczak to manufacture customized ballpoint pens. Within this Final Design Review (FDR) document, we present design updates since the CDR and implementation/assembly techniques. This work culminates in a solution to Mr. Lonczak’s needs which is analyzed in three subsystems: main control, spindle position tracking, and user interface. Within this report, we show the results of each subsystem’s verification process. These results prove that the design concept was met by describing …

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

Discourse Analysis In Engineering: Investigating Patterns In Brainstorming Conversations, Aimee Chiem

Master's Theses

Brainstorming is a critical part of the engineering design process and can have a significant impact on the outcomes of the overall project. While research has studied the outcomes of brainstorming and the ideas that teams generate, the role that language and conversation play in these activities is still relatively underexplored. Observing the different ways people use specific types of discourse can reveal how conversations can affect brainstorming itself. To that end, this research aims to answer the following questions:

1) What are the different kinds of discursive moves that students make during engineering brainstorming activities?

2) What patterns or …

Interactive Water Vortex Exhibit, Simon Way, Emily Laing, Roqaya Naseri, Makenzie Kan

Mechanical Engineering

The San Luis Obispo Children’s Museum requested an interactive water vortex exhibit to both engage and entertain inquisitive guests, ages two to eight. The goal was to design and manufacture an exhibit that would educate its users on the fluid mechanics behind water vortices. They activate the mechanics by spinning a wheel, which is perceived as the catalyst to manipulate the flow of water to successfully create a whirlpool. Our team has created an interactive display that will enlighten young minds, providing the museum with an educational exhibit which shares a concept not currently taught by any other. Our project …

Road Embedded Traffic Actuated Turbine (Retat), Derek Terry Cedillo, Jairo Fernandez Garcia, Alejandro Samaniego, Yosef Towfique

Mechanical Engineering

The Road Embedded Traffic Actuated Turbine (RETAT) project aims to revolutionize sustainable energy solutions by harnessing the power of passing vehicles to generate electricity. This Final Design Review (FDR) encapsulates the evolution of the project, from conceptualization to the tangible realization of the Verification Prototype created by a team of mechanical engineering students. The RETAT boasts an innovative design, incorporating square steel tubing and a unique linear-to-rotational energy conversion mechanism. This report provides a comprehensive overview of the design, implementation, and testing phases, highlighting achievements, challenges, and areas for refinement. As the RETAT project strives to contribute to a cleaner, …

Tagalong Trail, Sean Wahl, Jason Davis, Quinlan Stephens, Ryan Johnson, Vinh Vo

Mechanical Engineering

The Cal Poly mechanical engineering team working on the Path of Lights and Sounds for the Girl Scouts of California’s Central Coast has now completed their project. In the last quarter of their project, they were able to finalize their tile’s structural design while iterating through several electronics board designs. Through this iteration, they were able to create a final electronics board and designed a water-resistant enclosure to house the board. A new team member was added, allowing them to manufacture 28 tile structures and 30 electronics assemblies over the course of two and a half weeks. This proved to …

Slitter Blade Sharpener, Griffin Buchan, Regan Lane, Kinsale Sproule

Mechanical Engineering

Within this document, our team, “Think Sharpener”, will discuss the following work we have completed since the Critical Design Review: material and part procurement, the manufacturing process for our prototype, and a discussion of our results from testing our final Verification Prototype (VP). To summarize our team’s work during the last portion of this project, our design for the slitter blade sharpening mechanism required us to consult the IME department for materials and manufacturing guidance, order pneumatic components from various online hardware companies, and test our VP to verify we met the engineering design specifications. Our slitter blade sharpening mechanism …

Integrated Actuator, David Hefter, Mathew Smith, Amanda Westmoreland, Akanksha Maddi

Mechanical Engineering

This Final Design Review document outlines the senior project design that we, a team of four mechanical engineering students at California Polytechnic State University, are developing for Charlie Refvem, a lecturer in the mechanical engineering department. The final design has undergone significant modifications since the Critical Design Review, such as a redesigned vertical shaft, material changes, and the incorporation of belt tensioners. These redesigns are thoroughly discussed in the context of testing and assembly error resolution.

The document outlines the detailed steps for the production and testing of the design verification prototype. This includes the procurement and manufacturing of components, …

Maitreya Desalination, Riley Taft, Hudson Kispert, Brendan Dizon

Mechanical Engineering

This document relays the design and manufacture of a dual power input Reverse Osmosis desalination unit. It's power sources are electric drive and human power via recumbent seated cycling. Fresh water outputs range from 4 - 7 GPH for human power inputs of 150 - 280 Watts depending on the selected gearing ratio from the derailleur.

Band Motor Crankshaft For Hydrogen Combustion Engine, Lincoln Hofer, Jacqueline Mendoza Cortes, Austin Rhee, Roze Raymond

Mechanical Engineering

This report outlines the steps in which a group of four mechanical engineers at California Polytechnic State University California, San Luis Obispo, addressed an issue brought up by Professor Roger Benham from the Materials Department. The task included developing an automated and modular testing platform for a revolutionary concept crankshaft prototype – meant for a hydrogen combustion engine - developed and produced by the sponsor: Roger Benham. A testing platform is necessary to measure the performance of the shaft design created to eventually implement this subsystem into a complete hydrogen engine design. Values being tested include geometric validation, maximum static …

Design And Scale Model Of Wave Generator For The Testing Of Wave Energy Conversion Devices, Amanda Olla

Master's Theses

As the climate crisis draws more concern, research and development in wave energy as a renewable energy source has increased. Devices such as wave energy converters (WECs) are being researched, tested, and implemented to make wave energy a competitive power source. Testing of these devices is limited due to environmental concerns such as weather, location, and other issues. WECs require testing in a marine environment, however, performing testing in the actual environment may be difficult due to weather, access, mounting, and other issues. To eliminate environmental unknowns from testing, a wave simulator device can mimic wave behavior without the need …

Exoskeletons - Designing For Social Justice, Grace Cd Murphy

College of Engineering Summer Undergraduate Research Program

Many engineering professionals believe that discussions surrounding diversity, equity, and inclusion (DEI), and social justice do not belong in engineering because engineering is supposed to be a neutral or objective field. Through an extensive review of the literature and a survey sent out to potential users, the need for DEI in engineering was examined. Many current engineering projects do not take into consideration social justice principles which leaves certain groups further marginalized and disempowered while empowering a select few. Engineering has the opportunity to be a field of service, but first risks and benefits must be weighed and the outcome …

Robotic Origami Worm, Carter Josef, Michael Freeman, Mohammad Hasan

College of Engineering Summer Undergraduate Research Program

Soft robotics can solve many unique engineering problems. The ancient art of origami has inspired design for a new breed of robots. In this research, a novel fold design was created which has high linear stiffness, high bending stiffness, and the ability to deform omnidirectionally in order to turn. The robot is operated using a DC motor to expand and contract and electromagnets to control friction. The robot moves very quickly compared with many other origami robots in the literature. Other interesting ways to control friction were explored including expansion mechanisms. An origami design was created and tested that expands …

Sociotechnical Thinking In Statics And Dynamics, Raul Espinoza

College of Engineering Summer Undergraduate Research Program

This project introduced Canvas modules to instill a sociotechnical mindset in engineering students. By emphasizing the synergy between social and technical systems, the modules aim to produce engineers capable of crafting solutions that are technically adept and socially responsible.

Upper Limb Tensegrity Exoskeleton, Emily Mendyke, Sha'anan Levy, Alan Zhang

College of Engineering Summer Undergraduate Research Program

Tensegrity structures are composed of stiff rods and elastic cables suspended in a flexible tension network. Their inherent properties have several key advantages when used in assistive medical devices such as supportive braces or rehabilitation exoskeletons: 1) the lightweight and natural compliance reduces the power consumption required to operate the system; 2) the system stiffness and pretension can be individually tuned to accommodate the user’s needs; and 3) the impact-resistant properties can protect users in the event of collisions and falls. This project explores the design space of assistive tensegrity devices to augment human dexterity in the upper limb. Suitable …

Analysis Of Gait Parameters And Knee Angles In Ultimate Frisbee Players: Implications For Balance And Injury, Ethan Nikcevich

Master's Theses

Biomechanics research investigating gait and balance of ultimate frisbee players is an unexplored topic. Ultimate requires a wide range of motions that could improve balance and is also a sport prone to frequent injury. This study explores the impact of playing ultimate on gait parameters associated with balance and knee angles associated with joint injury. Gait trials were conducted on 8 ultimate players and 8 control participants between the ages of 18 and 23 to obtain total double support time, stance phase time, single support time, load response time, abduction-adduction (AA) angles, internal-external (IE) rotation angles, and flexion angles of …

Additive Manufacturing And Characterization Of Auxetic Structures, Jayesh P. Moore, Stephanie R. Ruzicka

College of Engineering Summer Undergraduate Research Program

An auxetic structure is an arrangement of unit cells that under a uniaxial load experiences expansion in both the longitudinal and transverse directions, resulting in a negative Poisson’s ratio (NPR). Research in auxetics has led to new insights into how non-linear mechanical reactions can be applied to various engineering fields. This project utilized stereolithography (SLA) 3D printing to manufacture auxetic test specimens to analyze of geometry-driven NPRs. With the distinctive mechanical properties of auxetic structures and vast applications, the future of product development of these geometries seems promising.