Mechanical Engineering Commons^™

Design Of Heterogeneous Structured Al Alloys With Wide Processing Window For Laser-Powder Bed Fusion Additive Manufacturing, Saket Thapliyal, Shivakant Shukla, Le Zhou, Holden Hyer, Priyanshi Agrawal, Priyanka Agrawal, Mageshwari Komarasamy, Yongho Sohn, Rajiv S. Mishra

Mechanical Engineering Faculty Research and Publications

Required microstructural attributes of an alloy vary with structural applications. The microstructural fine-tuning capability of laser-powder bed fusion (L-PBF) additive manufacturing (AM) enables application specific manufacture of the components. Such manufacture with L-PBF AM requires alloys that exhibit wide processing window and are amenable to multiple deformation mechanisms. However, high hot cracking susceptibility of Al alloys poses a barrier to such printability-performance synergy. In this work we show that an integration of, a) grain refinement through heterogeneous nucleation, and b) eutectic solidification, leads to crack-free parts at wide range of process parameters, microstructural heterogeneity, and hierarchy in the Al-Ni-Ti-Zr …

High Throughput Mechanical Testing Platform And Application In Metal Additive Manufacturing And Process Optimization, Ke Huang, Chris Kain, Nathalia Diaz-Vallejo, Yongho Sohn, Le Zhou

Mechanical Engineering Faculty Research and Publications

Agility of additive manufacturing (AM) warrants a development of an equally agile, high-throughput properties evaluation technique that can efficiently assess properties of AM specimens as functions of materials and process variables. High throughput (HTP) tensile testing rig has been developed, enabled by miniature sample design and Python based control codes for a full automation of testing and data processing. The rig is capable of testing 60 specimens per hour, much faster than conventional tensile testing. To luminate the merit of its use, an efficient process optimization workflow based on HTP testing is proposed and demonstrated on laser powder bed fusion …

Solar Decathlon Competition 2021, Khanh My Fleshman, Ashley H. Kim, Ian Grant Maclean, Erich Peter Fenczik Warnock, Carina Michaela Nani Monaco

Mechanical Engineering

This report is intended to outline all relevant background information, decisions, and design direction for our senior project at California Polytechnic State University, San Luis Obispo. We will be designing net-zero, affordable housing to compete in the attached housing division of the 2021 Department of Energy Solar Decathlon. With the increased urgency of climate change and focus on sustainability in construction, the importance of designing a net-zero structure is very apparent. Because there is a great need for affordable and sustainable housing in Watts, CA, we will be tailoring our design to meet this community’s needs. Details of the Solar …

Inverted Fluorescence Microscope, Matthew B. Pfeiffer, Spencer George Hann, Thomas James Eggenberger, Trevor Lee Blythe

Mechanical Engineering

Team F13 is composed of Trevor Blythe, Spencer Hann, Matthew Pfeiffer, and Thomas Eggenberger. We are all majoring in mechanical engineering and in our final year of study here at Cal Poly San Luis Obispo. This project is a continuation of a 2019-2020 senior project. The previous team designed and built a functioning inverted fluorescence microscope (IFM) from scratch. This device was created as a lab tool for undergraduate students to be able to perform experiments on microfluidic devices constructed in Cal Poly’s Microfabrication Laboratory. Although substantially functional, several design constraints had not yet been met. Our team has improved …

3-D Positioning System For Trackable Adjustments Of Papillary Muscles, Ryan Michael Winters, Micaela Andrea Bataclan, Christine Do, Giselle Morales

Biomedical Engineering

Redacted.

Hand Strength And Dexterity Enhancer, Julia Ann Denison, Autumn B. Rexford, Melissa A. Kurani, Christina K. Fong

Biomedical Engineering

Good Grips created the hand strength and dexterity enhancer project to meet the challenge presented by Bill Phelps. He has Inclusion Body Myositis (IBM), an inflammatory muscle disease characterized by progressive muscle weakness and atrophy. Bill has limited strength in both hands and lost the ability to bend his fingers, making it difficult to grip anything. He needed a device that would help with everyday tasks such as writing, lifting, and holding various objects.

Our team consists of four engineering students attending Cal Poly, San Luis Obispo. We researched, designed, manufactured, and tested a device that would fulfill the problem …

Development Of A Marine Biodegradable Target Balloon, Blake Samuel Robinson, Arash Sam Akhavi, David Leonardo Albarran-Martinez

Materials Engineering

The US Navy utilizes PVC target balloons, known as Killer Tomatoes, that are inflated onboard a naval vessel then deployed into the ocean to calibrate a variety of weaponry. The Navy has requested the investigation of biodegradable polymers to replace the PVC in attempts to reduce ocean waste that is generated from the leftover PVC material. After communicating with American Pacific Plastic Fabricators (APPF), the current manufacturer of the Killer Tomatoes, we gained an understanding of the manufacturing process and the material requirements that would allow a new material to be integrated into their current process. Two proprietary, trial polymers …

Inventory Locating With Quuppa: The Design And Development Of A Real-Time Process Monitoring Web Application Solution, Dylan C. Moreland, Trevor J. Howell, John W. Takiff, Patrick S. Dillon, Theo E. Fritz, William K. Mcintyre

Industrial and Manufacturing Engineering

Viasat, Inc. requires precise inventory tracking at their production facility in San Diego, CA. Viasat has installed the Quuppa indoor real-time locating system (RTLS), which it uses to track the real-time position of high-value work-in-process items. In its current state, the system only displays in-the-moment location information, with no available functionality for storing historical data for review, analysis, or visualization. In addition, the data displayed is noisy and prone to significant random error. This paper provides an overview of RTLS methods and technologies, assesses alternative solutions to Viasat’s issue, demonstrates our RTLS integrated web app solution, analyzes its impact, and …

Fabricating Tinicu Ternary Shape Memory Alloy By Directed Energy Deposition Via Elemental Metal Powders, Yitao Chen, Xinchang Zhang, Mohammad Masud Parvez, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this paper, a TiNiCu shape memory alloy single-wall structure was fabricated by the directed energy deposition technique with a mixture of elemental Ti, Ni, and Cu powders following the atomic percentage of Ti50Ni45Cu5 to fully utilize the material flexibility of the additive manufacturing process to develop ternary shape memory alloys. The chemical composition, phase, and material properties at multiple locations along the build direction were studied, using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Vickers hardness test-ing, tensile testing, and differential scanning calorimetry. The location-dependent compositions of martensitic TiNi and austenitic TiNi phases, mechanical properties, and functional properties …

Double-Acting Batch Reverse Osmosis Configuration For Best-In-Class Efficiency And Low Downtime, Sandra Cordoba, Abhimanyu Das, Jorge Leon, Jose M. Garcia, David M. Warsinger

School of Mechanical Engineering Faculty Publications

Energy consumption in reverse osmosis has decreased substantially over the last few decades thanks to the implementation of energy recovery devices, high efficiency pumps, and improved membranes. However, to further increase the adoption of the technology, its energy needs must still be reduced. Batch and semi-batch reverse osmosis configurations have shown potential to be the most energy efficient reverse osmosis variants, but have remaining inefficiencies from brine mixing and high downtime. In this study, we modeled in new detail a further improved double-acting batch reverse osmosis system that uses a high-pressure tank with a reciprocating piston. A high-pressure pump is …

Maize Tassel Detection From Uav Imagery Using Deep Learning, Aziza Alzadjali, Mohammed H. Alali, Arun Narenthiran Weeranampalayam Sivakumar, Jitender S. Deogun, Stephen Scott, James C. Schnable, Yeyin Shi

Department of Mechanical and Materials Engineering: Faculty Publications

The timing of flowering plays a critical role in determining the productivity of agricultural crops. If the crops flower too early, the crop would mature before the end of the growing season, losing the opportunity to capture and use large amounts of light energy. If the crops flower too late, the crop may be killed by the change of seasons before it is ready to harvest. Maize flowering is one of the most important periods where even small amounts of stress can significantly alter yield. In this work, we developed and compared two methods for automatic tassel detection based on …

Illustrating Important Effects Of Second-Order Sensitivities On Response Uncertainties In Reactor Physics, Dan Gabriel Cacuci

Faculty Publications

This paper illustrates the relative importance of the largest first- and second-order sensitivities of the leakage response of an OECD/NEA reactor physics benchmark (a polyethylene-reflected plutonium sphere) to the benchmark’s underlying total cross sections. It will be shown that numerous 2nd-order sensitivities of the leakage response with respect to the total cross sections are significantly larger than the largest corresponding 1st-order sensitivities. In particular, the contributions of the 2nd-order sensitivities cause the mean (expected) value of the response to differ appreciably from its computed value and also cause the response distribution to be skewed towards positive values relative to the …

Feasibility Study Of Radio Frequency Microelectromechanical Filters For Space Operation, Karanvir Singh

Theses and Dissertations

Piezoelectric contour mode resonator technology has the unique advantage of combining low motional resistance with the ability to define multiple frequencies on the same substrate. Contour mode resonators can be mechanically coupled together to form robust band-pass filters for the next generation of GPS satellites with extreme size reduction compared to electrically coupled filters. Piezoelectric zinc oxide (ZnO) contour mode resonators have the potential for monolithic integration with current ZnO transistor further reducing size, power consumption, and cost of filter modules. Barium strontium titanate (BST) contour mode resonators have incredible frequency tunability due to the fundamental nature of the thin …

Pod Stabilization, Lane Matthew Pledger, Becca Stefanich, Ian Mccandless, Patrick Salter, Kirk Kuran

General Engineering

We were tasked by Holmes Solutions to find a way to stabilize their patented SWITCHBACK passenger gondola system. This system is a self-propelled pod that transitions smoothly between cables and rails. The main goal for this project is to dampen side-to-side swing of gondola pods using a modular stabilization system. This device must be within these constraints: it must fit within a work envelope, must be safe for user and operator, must perform a dampening effect, and must be compliant with the current system. We formulated many ideas to achieve the goal, including making the pod more aerodynamic, adding sliding …

Consumer-Ready Insulated Solar Electric Cooker, Simon Ford, Sachin Gokhale, Brendan Lynn, Richard Nguyen

Mechanical Engineering

An insulated solar electric cooker, or ISEC, converts solar energy into electricity to cook food, boil water, provide heat or even help charge batteries. In this project, the focus is an ISEC with a phase change material (PCM) that helps store heat when the solar energy input is minimal, such as after the sun has set. Although a successful ISEC already exists that utilizes PCM, this product can be improved in many ways. The specific revisions investigated in this report are the improvement of the thermal efficiency with the implementation of a vacuum-sealed outer pot, the reduction of the overall …

Interactive Physics Display: Air Cannon, Marina Smeltzer, Sydney Hosokawa, Jordan Nguyen, Jessica Ouyang

Mechanical Engineering

The San Luis Obispo Botanical Garden (SLOBG) is a non-profit organization that provides a place for visitors to connect with and explore nature. The sponsors from SLOBG sought an interactive physics display to be implemented in their children’s garden that will educate children and adult visitors about physics concepts in a welcoming and comfortable atmosphere. The research done showed that customers are looking for a “wow” factor with the display to surprise and engage them. Patents showed the design and build of interactive playground equipment. Government reports described the curriculum for the target audience and also outlined the safety precautions …

Sustainable Energy Storage, Jacob S. Grillo, Alyse C. Coonce, Jack R. Linchey, Nick P. Schnorr

Mechanical Engineering

This Final Design Review document covers the work we, students at California Polytechnic State University – San Luis Obispo, have performed in collaboration with Mr. Harish Bhutani and Dr. Mohammad Noori. The project’s intent is to create an energy storage system for off-grid and developing region applications using alternative technologies to lithium-ion battery storage. We plan to manufacture and assemble a scale model of the energy storage system to prove effectiveness and practicality. This system will store enough energy to power basic appliances and essential devices for a house or community. The chosen design direction will be a flywheel, as …

Configurable Seat Track Latching Mechanism, Emily Sun, Kai Quizon, Rick Hall, Daniel Turn, Nicholas Holman, Alexander Kuznik, Jacob Winkler, Audrey Trejo, Phoebe Zeiss, Steven Kam

Mechanical Engineering

The reconfigurable seating system is a flexible seating solution for transit vehicles that allows operators to change the configuration of the floor plan in a timely manner in order to accommodate change in needs. This project consists of three senior project teams each working on a component of the design: system, track & latch, and articulation. Descriptions of the responsibilities of each team will be discussed below.

Prosthetic Foot Shell, Christopher Menke, Colton Arbuckle, Jacob Rodriguez

Mechanical Engineering

Prosthetic foot shells are designed to fit around lower limb prosthetics to be able to fit shoes and several types of footwear. They are currently designed in a way that they wear through very quickly if used in an active lifestyle. The current designs on the market are designed for geriatric use. The sponsor for this project Mr. Dana Cummings, would like for the team to produce a product that extends current foot shell’s life. This document explains includes the team’s research process, the design process, and the main functions of what the team designed for. It will also show …

Composite Pegboard, Asa J. Cusick, Luis Corrales, Joelle Hylton, Wyatt Pauley

Mechanical Engineering

Many of those with mobility limitations who are told they will need a wheelchair for the rest of their lives can actually begin to stand and walk again given the proper tools and support. The current design for a wheelchair seeking to support this process is overly complex, heavy, and exhibits some features that could potentially pose a serious health hazard to those using it. The scope of this project is to aid in the design of an adaptable composite wheelchair frame that can be both lightweight and strong, while still allowing for physical diversity of potential users. Through research …

Transportable, Jung Sub Kim, Ellie Kitabjian, David Yang, Christopher Macias

Mechanical Engineering

This document is a Final Design Review (FDR) report for team TransporTable, a quartet of mechanical engineers at California Polytechnic State University, San Luis Obispo (Cal Poly). It chronicles our design and validation process through final design phase. Our project: to design and test concepts for a stackable table that streamlines group work. After conducting user/sponsor interviews and background research, we found that many products already exist, but none meet the specific blend of requirements set out by our sponsor. They include fast deploying/stowing times, durability, stiffness, and manufacturability. We ideated on the table’s functions, distilling many ideas into three …

Space Suit Attachment Quick Release System, Elyse C. Gillis-Smith, Andres I. Elzaurdia, Cole H. Stanton, Michael T. Roth

Mechanical Engineering

NASA plans to make it back to the Moon by 2024 with their Artemis Program, and stay there for a longer period of time to conduct research which will support the future of space exploration. While on the lunar surface, astronauts need to maximize their efficiency by carrying tools on their Exploration Extravehicular Mobility Unit (xEMU), and to accommodate this need, the Extravehicular Activity (EVA) Tools Team is pursuing a utility belt concept. The objective of this project is to develop a system capable of interfacing between the utility belt and any given tool, while also accommodating numerous restrictions and …

Uav For Medical Equipment Distribution, Richard Barakat, Logan Christensen, Brandon Halebsky, Justin Slavick

Mechanical Engineering

This Final Design Review report documents the senior project participating in the Vertical Flight Society’s 38th Annual Student Design Competition sponsored by The Boeing Company. The goal of this project and competition is to develop an unmanned vertical lift for medical equipment distribution capable of safely delivering a 50 kg payload over distances up to 200 km. This system must be autonomous and have a backup plan to land if any part of the system malfunctions. We discuss the research and justification that drove the selection of the aircraft configuration, a winged quadcopter with a rear propeller. Furthermore, we document …

Hands-On 3d Printed Dynamics Activities, Dakota Baker, Jacob Lindberg, Andrew Meyenberg, Junnior Rodriguez

Mechanical Engineering

The advancement of 3D printing has allowed everyday individuals to rapid prototype and manufacture in a more efficient, cost-effective, and timely manner. This has paved the way for a more adaptable educational model, by allowing instructors to easily access alternative instruments for teaching. By providing students with tangible tools, they will better be able to grasp complex principles. Dynamics professors need a way in which they can easily access these academic tools, transport them to and from class, and teach multiple dynamics principles through variations of a single 3D printed kit. Interviews with professors and students were conducted to gain …

Adaptive Robotic Chassis (Arc): Robocrop A Smart Agricultural Robot Toolset, Steven Bucher, Krissy Ikeda, Brooke Broszus, Alejandro Gutierrez, Ariana Low

Interdisciplinary Design Senior Theses

RoboCrop is a payload system that attaches to an existing modular drivetrain to support the agriculture industry with their primary challenge of labor shortages. ARC: RoboCrop features three degrees of freedom as an XYZ Cartesian robot and is intended specifically for pruning strawberry flowers. The image bay camera attached to RoboCrop’s frame identifies the strawberry flowers, communicates their XYZ coordinates, and then the Cartesian robot moves to the desired locations. The snipping toolhead is interfaced at the bottom of the Z-stroke and performs the snipping process. RoboCrop has a proven success rate of at least 70% of flowers pruned in …

A Mems Pressure Sensor Using Electrostatic Levitation, Mohammad Mousavi, Mohammad Alzgool, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Applying electrostatic levitation force to the initially-closed gap-closing electrodes of our micro-electro- mechanical system (MEMS) creates multi actuation mechanisms, and opens a new world to the MEMS applications.

Electrostatic levitation allows us to measure physical quantities, such as air pressure, by exploiting pull-in instability and releasing. The beam starts from a pulled-in position by applying a voltage difference between two gap-closing electrodes. When enough voltage is applied to the side electrodes, the cantilever beam is released. At the release instant, electrostatic forces, restoring force, and surface force are applied to the cantilever. According to the experimental results of this work, …

Power Output Modeling And Optimization For A Single Axis Tracking Solar Farm On Skewed Topography Causing Extensive Shading, Logan J. Smith

Master's Theses

Many utility-scale solar farms use horizontal single axis tracking to follow the sun throughout the day and produce more energy. Solar farms on skewed topography produce complex shading patterns that require precise modeling techniques to determine the energy output. To accomplish this, MATLAB was used in conjunction with NREL weather predictions to predict shading shapes and energy outputs. The MATLAB models effectively predicted the sun’s position in the sky, panel tilt angle throughout the day, irradiance, cell temperature, and shading size. The Cal Poly Gold Tree Solar Farm was used to validate these models for various lengths of time. First, …

Failure Analysis Of The Ulnar Collateral Ligament For Youth Baseball Pitchers, Carlos Soto

Master's Theses

The objectives of this study were to (1) use kinetics from motion analysis and inverse dynamics to calculate the stress experienced by the ulnar collateral ligament (UCL) during a typical pitch cycle, (2) compare calculated maximum UCL pitching stresses to failure properties, and (3) investigate correlations between UCL stress with anthropometric and pitching biomechanical parameters. Prior motion analysis experiments of eighteen 10- to 11- year-old baseball pitchers throwing 10 fastballs were analyzed. Maximum internal elbow varus torques were calculated using inverse dynamics methods during a typical pitch cycle. Calculations used axial loading stress equations and maximum internal elbow varus torques …

Novel And Fast Peridynamic Models For Material Degradation And Failure, Siavash Jafarzadeh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fracture is one of the main mechanisms of structural failure. Corroded surfaces with chemically-induced damage are, notably, potential sites for crack initiation and propagation in metals, which can lead to catastrophic failure of structures. Despite some progress in simulating fracture and damage using classical models, realistic prediction of complex damage progression and failure has been out of reach for many decades. Peridynamics (PD), a nonlocal theory introduced in 2000, opened up new avenues in modeling material degradation and failure. Existing numerical methods used to discretize PD equations, however, are quite expensive as the PD nonlocal interactions make them unaffordable for …

A Novel Drive Cycle Simulation Model For Gasoline Engines To Investigate Bandwidth Coverage Of Emission Performance And Fuel Consumption With Engine Control Parameters, Martin Giencke

Doctoral

The presented work is offering an investigation how the bandwidth of vehicle specific attributes is impacting engine control parameter requirements for warmup control of the catalytic converter, aiming to ease the development process by providing mathematical means for an automatic generation of control settings. For the specific purpose, a novel drive cycle simulation approach is developed, focusing on emission performance and fuel consumption of a gasoline engine. Steady state and quasi steady state measurements are collected to quantify the impact of modifications to control parameters on emission concentration, exhaust gas temperature and engine torque, especially directly after a cold start. …