Engineering Commons^™

Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz

Master's Theses

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to …

Design And Control Of Fiber Encapsulation Additive Manufacturing, Matt Saari

Mechanical Engineering Research Theses and Dissertations

This work presents the design, development, and analysis of the Fiber Encapsulation Additive Manufacturing (FEAM) system developed at the Laboratory for Additive Manufacturing Robotics \& Automation at the Lyle School of Engineering at Southern Methodist University. The innovation introduced by FEAM is the ability to insert a continuous fiber of different material into the flowing extrudate. Correctly positioning the fiber feed inside the extrudate while turning the fiber in arbitrary directions is a critical aspect of the technology. This will allow for the full exploitation of the capabilities of the FEAM technology to produce robotic components that actuate and sense. …

Repurposing Plastic Waste In El Cercado, Joseph Dooling, Kirby Townsend, Brendan Smith

Honors Thesis

This project aims to assist the community of El Cercado in the Dominican Republic in turning their plastic waste into useful products. The design team developed a first iteration shredder, injector, and aluminum mold which future design teams could further iterate in order to make products out of waste plastic. Different products were researched to ensure that they can be sold or used in the community. The goal of producing these items is to stimulate economic activity in the community by creating economic opportunity. The design shall also be sustainable in three ways. It shall reuse plastic waste while also …

Universal Bike Suspension Design, Ernesto Huerta, Gregory Ryan Ritter, Chris Michael Fedor, Michael Wu

Mechanical Engineering

Cal Poly Bike Builders (CPBB) is a student club at Cal Poly helping students design and fabricate their own bicycles. Currently, club members build rigid frames and mountain bikes with only front-suspension–commonly referred to as a “hardtail”. As more students join the club, interest grows in building full-suspension mountain bikes (FSMTB). Designing and manufacturing a mountain bike rear-suspension system requires a diverse skillset and a substantial time commitment. As a result, individual efforts building FSMTB have proven unsuccessful. The scope of this project is to develop a defined method and necessary tools such that all CPBB members can efficiently build …

Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano

Graduate Theses and Dissertations

This research proposes novel fault adaptive workload allocation (FAWA) strategies for the health management of complex manufacturing systems. The primary goal of these strategies is to minimize maintenance costs and maximize production by strategically controlling when and where failures occur through condition-based workload allocation.

For complex systems that are capable of performing tasks a variety of different ways, such as an industrial robot arm that can move between locations using different joint angle configurations and path trajectories, each option, i.e. mission plan, will result in different degradation rates and life-expectancies. Consequently, this can make it difficult to predict when a …

Final Design Report For Human Powered Vehicle Drivetrain Project, Derek Fromm, Luke Opitz, Michael Juri, Olivier Côté

Mechanical Engineering

The Cal Poly Human Powered Vehicle Club is building a bike to surpass 61.3 mph in 2019. The club and their mentor, George Leone, have proposed a senior project to design, build, and test the drivetrain for this year’s human powered vehicle. Research into human powered vehicles and their drivetrains has shown that the power that a rider can output and the efficiency at which the rider can pedal depend extensively on the design of the drivetrain. Despite the existence of standard bicycle drivetrain designs, the senior project team has found that the best design to meet the club’s requirements …

Danny’S Recumbent Bike Accessibility Device Final Design Report, Joseph J. Lee, Huy Nguyen, Jack Mcatee, John Kulick

Mechanical Engineering

The purpose of this document is to fully define our design solution and explain our manufacturing and testing results. Our project’s goal is to find a way to allow Danny Knutson, a retired Navy pilot and incomplete quadriplegic with limited use of his arms and an impaired sense of balance, to enter and exit his recumbent tricycle without any discomfort for him or his aide. We completed multiple interviews with Danny, patent research, existing product research, and other technical literature research in order to fully understand the problem. We synthesized this information to create a concrete list of customer wants …

Vaccine Cooler For The Global Poor, Benjamin J. Larson, Cooper E. Gibson, Eilbron Younan, Cody R. Volk

Mechanical Engineering

Cal Poly physics professors Peter Schwartz and Nathan Heston approached the Solar Freeze team with the problem that remote communities in Africa have limited access to modern-day medicine or vaccines. They suggested that we try and design a cooling device that can keep vaccines cold for multiple days at a time while the medicine is transported to remote villages. Currently, there are vaccine cooler products on the market, but most of them are very expensive or lack portability. Peter and Nate have tasked the Solar Freeze team to come up with a less expensive solution that is also portable and …

High Strollers, Braeden Hammond, Morley Perrin, Reid Bartels, Juan Rodriguez

Mechanical Engineering

This report documents the final product of Jonathon’s new lightweight stroller. The Mechanical Engineering team from Cal Poly, High Strollers, began the project to create a lightweight stroller for the project sponsor, Nina Aguayo, and her son, Jonathon Aguayo, in Fall of 2018. Jonathon is diagnosed with Delayed Brain Development and Hypotonia with some characteristics of Cerebral Palsy. He has a 50lb high intensity stroller to go to and from school. Mrs. Aguayo needed a stroller that is easier to transport while still meeting all of Jonathon’s needs. The re-designed stroller will make leisurely outings for Mrs. Aguayo and Jonathon …

Framed Human Powered Vehicle Frame, Keyanna Brielle Henderson, Brendon Howard Morey, Kyra Noelle Schmidt, Austin Patrick Henry

Mechanical Engineering

The following is the Final Design Review (FDR) Report for Framed, a team tasked with designing and fabricating the frame of the 2018-2019 Cal Poly Human Powered Vehicle (HPV) Club bike. The bike is to be raced at the 2019 World Human Powered Speed Challenge in Battle Mountain, Nevada with the goal of breaking the American collegiate speed record. The purpose of the FDR Report is to introduce the project’s background and objectives, discuss the final design, and present the results of manufacturing and testing. Prior to beginning work on the design of the frame, the group conducted extensive research …

Blockchain Technology Based Supply Chain Systems And Supply Chain Performance: A Resource-Based View, Madhavi Latha Nandi

Theses and Dissertations

Blockchain technology (BCT) is set to transform firms’ present ways of managing supply chains. This thesis explores how the efforts by firms to integrate BCT into their supply chain systems and activities, can enable certain supply chain capabilities and subsequently, improve supply chain performance. Using an abductive research approach, qualitative content analyses of 126 cases of firms’ efforts in BCT-based supply chain systems (BCT-SCS) across multiple industries are conducted to identify the BCT-enabled supply chain capabilities and their performance outcomes. Findings reveal that the present BCT-SCS efforts are mainly oriented towards improving the operational-level capabilities namely, information sharing and coordination …

Design Of A Bedside Walker-Cane Hybrid To Aid Senior Adults Avoid Falls During Night Walks, Jorge L. Gutierrez

Theses and Dissertations

The objective of this research and development work is to design a device to help senior adults prevent fall during night walks indoors. The problem of elders falling at a night setting was found to be caused by the multiple environmental and medical conditions. The target demographic was found to be seniors from age 65 and older. Several occupational therapists and two physical therapists were consulted to gain knowledge on elders' behavior, possible improvements on current existing devices, and feedback regarding the early prototype built. Several products and patents were researched with a lack of findings on similar products that …

Additive Manufacturing Of High Performance Flexible Thermoelectric Generators Using Nanoparticle Inks, Tony Valayil Varghese

Boise State University Theses and Dissertations

Flexible thermoelectric devices are attractive power sources for the growing demand of flexible electronics and sensors. Thermoelectric generators have an advantage due to no moving parts, silent operation and constant power production with a thermal gradient.

Conventional thermoelectric devices are rigid and fabricated using complex and relatively costly manufacturing processes, presenting a barrier to increase the market share of this technology. To overcome such barriers, this work focuses on developing near ambient-temperature flexible thermoelectric generators using relatively low-cost additive manufacturing processes. A screen printable ink was developed for transforming nanoparticle ink into high-performance flexible thermoelectric generators with a peak thermoelectric …

A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande

Electronic Theses and Dissertations

Additive manufacturing or 3d printing is the process of constructing a 3-dimensional object layer-by-layer. This additive approach to manufacturing has enabled fabrication of complex components directly from a computer model (or a CAD model). The process has now matured from its earlier version of being a rapid prototyping tool to a technology that can fabricate service-ready components. Development of low-cost polymer additive manufacturing printers enabled by open source Fused Deposition Modeling (FDM) printers and printers of other technologies like SLA and binder jetting has made polymer additive manufacturing accessible and affordable. But the metal additive manufacturing technologies are still expensive …

Development Of A Multi-Probe Kelvin Scanner Device For Industrially-Relevant Characterization Of Surface-Activated Carbon Fiber Reinforced Thermoplastic Composites, Kirby Simon

McKelvey School of Engineering Theses & Dissertations

Carbon fiber reinforced thermoplastic (CFRTP) composites are becoming increasingly attractive materials in manufacturing due to their lightweight nature, mechanical strength, and corrosion resistance. Surface activation of these materials is usually required during processing to increase the bond strength of assemblies (aerospace and automotive industries) or improve adhesion with implants (biomedical industry). Industrially-relevant, nondestructive quality control methods for assessing the activation state of these materials do not currently exist, however. Applying principles discovered through the use of scanning probe microscopy, a multiple-probe Kelvin scanning (MPKS) device has been developed that can assess the uniformity of the activation state of plasma-treated CFRTP …

Design Of A Scara Based Mobile 3d Printing Platform, Zachary Hyden

Mechanical Engineering Undergraduate Honors Theses

Currently 3D printers rely heavily on people to run them, there is no automatic way to start a new print after one has finished. On top of this 3D printers are limited in the area they can print on. Even though the additive manufacturing market is rapidly growing and is increasingly being used in product manufacturing there has yet to be a solution to this problem. This research proposes using mobile 3D printing robots to solve both of these issues. The proposed prototype utilizes a Selective Compliance Assembly Robot Arm (SCARA) based robot capable of cooperatively manufacturing parts. This allows …

Torch Mounted Wire Nipper, Steven D. Patrick, Matt Montgomery, Ben Rouse, Garrett D. Foust

Chancellor’s Honors Program Projects

No abstract provided.

Final Design Report For The Bioburden Pre-Cleaning Device And Dr. Mark Rasnake At The University Of Tennessee Medical Center, Katherine Elizabeth Stiles, Megan Pitz, Kayla Franklin, Simran Dayal, Austin Bullock

Chancellor’s Honors Program Projects

No abstract provided.

Less-Than-Lethal Self Defense Device With An Acoustic Element, Anthony Taibi

KSU Journey Honors College Capstones and Theses

This creative capstone project involves the conception, design, and creation of a less-than-lethal self defense device with an integrated sound board to control the acoustic element. Theoretically, this device is capable of deterring potential threats without causing any serious harm or any long-term damage. When starting this project, I was very focused on sonic warfare, and how to harness the power of ultrasonic and infrasonic sound waves to subdue to target; however, I concluded that using resonant frequencies to deter a human being is too dangerous, expensive, and can have negative effects for the user of the device if used …

The Influence Of Process Variables On Physical And Mechanical Properties In Laser Powder Bed Fusion, Joshua Robert Koepke, Bradley Jared, Yu-Lin Shen

Mechanical Engineering ETDs

Laser powder bed fusion additive manufacturing consists of a process that incorporates many process variables into fabricating parts. This study investigated several of these process variables and determined their influence on part properties. The process variables investigated include laser power, velocity, focus offsets, layer thickness, and powder particle size. Physical properties will be compared including surface roughness, form, and density. Tensile testing provided mechanical properties including unloading Young’s modulus, ultimate tensile strength, yield strength, uniform elongation, and ductility. Process maps will be developed that will provide recommendations for these process settings. It will be shown that these laser settings can …

Hybrid Laser/Arc Welding Of Difficult-To-Weld Thick Steel Plates In Different Joint Configurations: Issues And Resolutions, Nima Yazdian

Mechanical Engineering Research Theses and Dissertations

Difficult-to-weld steels are ferrous alloys that are characterized by a low thermal conductivity, and large thermal expansion coefficient. These intrinsic features contribute to a high level of distortion and cracking susceptibility during joining of these types of steels. In an effort to address the issues associated with difficult-to-weld steels, highly concentrated beam spots like electron and laser beam welding were developed. Usage of tightly focused heat sources have been accompanied by several challenges. An extremely precise fit-up requirement was considered as the most significant issue corresponding to application of either laser or electron beam. Recently, it was found that the …

Analytical And Experimental Study Of Laser Cladding Of Ni/Wc Metal Matrix Powders Reinforced With Rare Earth Elements Using A High Power Direct Diode Laser, Mohammed Sayeed

Mechanical Engineering Research Theses and Dissertations

The corrosion and wear are major limiting factors for steel in the harsh environments and can be controlled by depositing protective passive coatings. Nickel based alloy cladding of steel offers a solution by enabling better corrosion and wear resistance, and high bonding strength. The laser surface cladding of steel was conducted using a high power direct diode laser. Layers of tungsten carbide in Ni (40%Ni-60%WC) combined with 1% and 2% Lanthanum Oxide (La₂O₃) and Cerium Oxide (CeO₂) were deposited on ASTM A36 steel substrate. The X-ray diffraction and scanning electron microscopy were employed to …

Experimental Investigation Of The Manufacture Of Tunable Graphene Oxide Filter Membranes Using Intense Pulse Light, Joshua H Kotter

Electronic Theses and Dissertations

Reduced graphene oxide is a thin, strong, and inexpensive material with a channel and pore structure that make it a promising candidate for a filtration material. Reduced graphene oxide has been produced and tested in the laboratory, but a lack of scalable manufacturing techniques have limited its commercial use.

This thesis has shown that graphene oxide can be rapidly manufactured with an industrially scalable flash reduction process. The flash reduction process uses 0.58 millisecond pulses from a xenon lamp to reduce the graphene oxide film in less than a minute. Results for partially reduced graphene oxide membranes tuned by the …

Design And Manufacture Of An Inertial Cascade Impactor For Industrial Hygiene Purposes, Hector Joel Gortaire

Mechanical & Aerospace Engineering Theses & Dissertations

Inertial cascade impactors are devices commonly used for industrial hygiene and pharmaceutical studies. Their main purpose is to separate particulate matter suspended in aerosols according to their sizes, which can vary from over 10 µm to 0.5 µm. Their versatility and ease of operation make them suitable for on-site sampling; however, designing them requires a careful consideration of the different geometric parameters that characterize them.

In this thesis, a 5-stage inertial cascade impactor was designed, modelled, constructed, and tested. The main design parameter was the volumetric flow rate, 40 l/min, which was provided by a vacuum pump. By continuous iterations, …

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior …

Process Parameter Development Of Additively Manufactured Af9628 Weapons Steel, Erin M. Hager

Theses and Dissertations

The manufacture of components in Additive Manufacturing processes is limited by the range of materials available. Qualification of materials for Additive Manufacturing is time intensive, and is often specific to a single type of machine. In this study, an approach to selecting power, speed, and hatch spacing values for a newly powderized material, AF9628 weapons steel, is described that results in highly dense (>99.9%) parts on an MLab 200R Cusing. Initial power and speed values used in a weld track study were selected based on a survey of parameters used on similar materials, with a focus on the energy …

Microscale Metal Forming: Mesoscopic Size Effect, Extrusion And Molding, Bin Zhang

LSU Doctoral Dissertations

The continuing trend of metallic device and product miniaturization has motivated studies on microscale metal forming technologies. A better understanding of materials’ mechanical response and deformation behavior is of importance for the design and operation of micro metal forming processes. In this dissertation, uniaxial compression testing was conducted on Al ring and pillar specimens with characteristic dimensions at meso to micro scales. The experimental data reveal inadequacies of the existing surface layer model and provides a baseline for delineating deformation mechanisms in micro metal forming operations. Microscale reverse extrusion experiment was carried out on Cu and Al rod specimens with …

Torsional Stiffness Of A Race Car, Reiley A. Schraeger, Cameron Kao, Raymond Deng, Omar Roman

Mechanical Engineering

Torsional stiffness plays a major role in any road vehicle. To understand torsional stiffness of a vehicle and make future iterations and improvements, a proper torsional stiffness jig is required to prove accurate and useful data. This report encompasses the new and improved testing jig and potential improvement ideas for more accurate results. With real data result relating to FEA calculations, designers can be confident in the FEA changes to torsional stiffness is accurate and will yield the probably results they desired. This report shows the methodology, manufacturing process and testing procedure to use on any Baja or SAE vehicle …

Investigation Of Design, Manufacture, Analysis, And Test Of A Composite Connecting Rod Under Compression, Thomas Juhl Rohrbach

Master's Theses

Composite materials hold great potential for the replacement of traditional materials in machines utilized on a daily basis. One such example is within an engine block assembly where massive components inherently reduce the efficiency of the system they constitute. By replacing metal elements such as connecting rods, cylinder caps, or a crank shaft with composite alternatives, a significant increase in performance may be achieved with respect to mechanical strength, thermal stability, and durability, while also reducing mass. Exploration of this technology applied to a connecting rod geometry was investigated through a combination of process development, manufacturing, numerical analysis and testing. …

The Bracket, Ryan Jerome Skerbeck

All Undergraduate Projects

• Abstract
• Bracket, casting, aluminum; if any of these for mentioned words interest you in anyway this is a document that you should read.
• There is a need for a compressor to be mounted to the front of a Cummins engine so that compressed air would be available on a work truck. The York compressor and the engine were known quantities, so what this project covered was the bracket that mounted the compressor to the engine and the manufacturing processes. The process chosen to make the bracket was aluminum casting; casting was chosen because of the ease of making many parts …