Manufacturing Commons^™

Modeling And Simulation Of Micro Electrical Discharge Machining Process, Bai Shao

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

Micro parts and systems are playing crucial roles in the area of semiconductor, biomedical device, micro fluid devices, automotive, aerospace and so forth. Micro manufacturing is one of the most important technologies in realizing miniaturization. Compared to other micro manufacturing methods, micro-EDM is drawing lots of attention due to its ability to machine complex 3D parts regardless of the hardness of the workpiece material.

Micro-EDM is the cumulative result of numerous single discharges; therefore, it is crucial to understand the single discharge material removal process in micro-EDM. However, due to the stochastic nature and complex process mechanism, micro-EDM, including its …

Hand Adjustable Position Override For Large Exit Bin, David J. Michalik, Alex Wiseman, Kelsey Grover, David Bryan

Chancellor’s Honors Program Projects

No abstract provided.

Gaf Glass Mat Splice Table Improvements, Grant Haug, Kevin Lansang, Ronald Lam, Michael Mooney

Mechanical Engineering

The GAF asphalt shingle production line in Shafter, CA requires continuous operation in order to maximize production efficiency. The assembly line process begins with feeding a large roll of fiberglass web into an accumulator. However, once the fiberglass roll approaches the end, it must be spliced with a new roll in order to maintain continuous feed into the production line. The splicing process must be fast and reliable to prevent any delay of the production line. Currently, this process is performed by two workers who manually feed the new fiberglass roll, align the two mats, cut the mats, apply glue …

Child Carrier: Senior Project, Cordell Hollingsworth, Jacob Puppo, Drew Sapp

Mechanical Engineering

No abstract provided.

Swerve, Kaitlin A. Castillo, Cichasky A. Catherine

Industrial and Manufacturing Engineering

Carpooling yields great benefits environmentally, socially, and economically for carpooling, however there is no easy to use, safe, and enjoyable application for people to connect with others who are both close in proximity and have schedules that match currently. By creating a database and visual mock ups, our senior project creates the basis for an application called Swerve that matches users by location and schedules and has social and economic incentives. Our research allowed us to further understand the social, environmental and economic benefits and incentives of carpooling. We also looked into current carpooling websites and applications and could not …

Multi-Restaurant Delivery Service Design And Financial Analysis, Dylan Davis Fuller

Industrial and Manufacturing Engineering

When found on campus all day and in need of a quick meal before the next class what are the options for you as a Cal Poly student or faculty? Campus dining is the only option that can meet the typical demand you have of speed and convenience. Restaurants with food delivery often don’t have the variety or take to long for delivery. The goal is to provide a delivery service with the speed of getting a meal on campus but with the variety and quality of the restaurants found in downtown San Luis Obispo. Looking at existing businesses providing …

Startup Social Responsibility: A Concentrated Social Audit Of Halt Medical Inc., Matthew Frank Rosa

Industrial and Manufacturing Engineering

Halt Medical Inc. is a biomedical device startup whose managers are interested in assessing their levels of employee satisfaction and organizational well-being. They want to know if their employees are cooperating, if departments are cohesive, and if everyone is happy. To evaluate Halt Medical’s social capital and environment, a social responsibility audit will be conducted concentrated specifically on the organization’s social and ethical initiatives to its employees. This analysis requires interviews of managers, observations of cultural diffusion, and employee opinions on a variety of business areas. The five areas of focus for this audit are the company’s accommodation of each …

Design, Fabrication, And Testing Of A 3d Printer Based Microfluidic System, Carlton A. Mcmullen

Graduate Theses and Dissertations

A pneumatically actuated PDMS based microfluidic devices were designed and fabricated by soft-lithography. Two types of molds were fabricated out of different material for this experiment. The first mold, (device 1), was fabricated from a sheet of Polymethyl methacrylate (PMMA) material, similar to Plexiglas. The device features were micro-engraved onto the face of the material. The second mold, (device 2), was fabricated from the use of fused deposition modeling (FDM) 3D printing. The pumping efficiency of the PDMS devices was analyzed through the characterization of the micro-pumps flowrate with respect to the pumps driving pressure and the actuation frequency. Tested …

Carbon Articulating Backpack Spine, Salvatore Monforte Iii, Darci Lawrence, Savan Patel

Mechanical Engineering

In the field, firefighters and Urban Search and Rescue (USAR) personnel need to transport variable loads efficiently, safely, and comfortably while simultaneously performing certain physical tasks. Current models of external and internal framed backpacks distribute the load of a pack efficiently, but do not allow for the natural movement of the wearer. Wolfpack Gear, Inc. proposed the need for a system which both effectively carries a load and allows for the unhindered natural movement of the user. The goal of this project was to design, build, and test an articulating backpack support system. The first stage of the project comprised …

Process Development For Compression Molding Of Hybrid Continuous And Chopped Carbon Fiber Prepreg For Production Of Functionally Graded Composite Structures, Corinne Marie Warnock

Master's Theses

Composite materials offer a high strength-to-weight ratio and directional load bearing capabilities. Compression molding of composite materials yields a superior surface finish and good dimensional stability between component lots with faster processing compared to traditional manufacturing methods. This experimental compression molding capability was developed for the ME composites lab using unidirectional carbon fiber prepreg composites. A direct comparison was drawn between autoclave and compression molding methods to validate compression molding as an alternative manufacturing method in that lab. A method of manufacturing chopped fiber from existing unidirectional prepreg materials was developed and evaluated using destructive testing methods. The results from …

Evaluation Of Two-Phase Evaporation Pressure Drop Correlations For Low Refrigerant Mass Flux., Anna Fenko

Electronic Theses and Dissertations

This study was conducted to evaluate three currently popular two-phase pressure drop models for extremely low velocity refrigerant flow through smooth circular evaporators in household refrigeration systems. Experimental data was taken at mass fluxes under 70 kg/m²s for two refrigerants, R134A and R600A, internal diameters of aluminum evaporators ranging from 0.186 to 0.317 inches, U-bend internal radii ranging from 0.342 to 0.750 inches in horizontal and vertical orientations of evaporators. The geometry of the samples closely resembled a commonly used serpentine shape with multiple U-bends experiencing both, up- and down-flow of the refrigerant. Two empirical models, Müller-Steinhagen & …

Process Parameters And Foaming Agents Used In Manufacturing Of Aluminium Metallic Foams: A Review, Sri Ram Vikas K.,, N. Raghu Ram,, Ch. Kishore Reddy,, V.V. Sridhara Raju

Innovative Research Publications IRP India

Porous metals and metallic foams are composite materials in which one phase is gaseous and another phase is solid metal. The mechanical behavior of these materials depends mainly on the mechanical properties of the solid metallic phase, the structural configuration of the solid and the density of the composite ρc, relative to the density of the solid phase ρs. The primary distinction between a porous metal and metallic foam is the relative density, metal gas composites with a relative density (ρc/ρs) above 0.3 are generally considered porous materials, while those with a relative density below 0.3 are generally considered to …

Review On The Suitability Of Conceptual Performance Measurement Systems For Lean Manufacturing, Dilanthi M. G.S

Innovative Research Publications IRP India

Lean manufacturing is implemented to improve any organizational performance so that its performance should be measured to assure the organizational goal attainment. But the past studies have not yet suggested any specific performance measurement system for lean manufacturing. Therefore this paper reviews the conceptual performance measurement systems and their suitability to measure the lean performance and hence argues that a new performance measurement framework should be developed.

Optimizing A Hammer Forging Progression For A Large Hand Tool, Edgar Espinoza

Master's Theses (2009 -)

In the forging industry of today the need for United States based companies to reduce cost and maintain or improve the quality of a product has become essential in order to remain competitive. A company such as Green Bay Drop Forge (GBDF), a manufacturer of standard and custom steel forgings, was tasked with improving the forging process of one of their large hand tool products. A large wrench, forged at GBDF was noticed to contain a large amount of flash and excessive amount of hammer blows required to forge the part. The large amounts of flash and excessive hammer blows …

Investigation Of Surface Topography Effects On Metal Flow Under Lubricated Hot Compression Of Aluminum, Justin Irvin Kurk

Master's Theses (2009 -)

An investigation was conducted to study the effects of die surface topography, specifically surface roughness and lay, on metal flow and the friction factor under lubricated hot compression. 6061-T6 aluminum rings and square bar stock specimens were compressed on H-13 tool steel platens machined with a unidirectional lay pattern to six different roughnesses between a R 10 and 240 μin. A lab based hydraulic press mounted with an experimental die set was used for all testing. Repeated trials were conducted using high temperature vegetable oil and boron nitride lubricants. Metal flow was quantified as a function of surface roughness, lay …

Diseño De Una Máquina Extrusora Automática Para La Fabricación De Retacados De Arcilla Empleados En La Industria De La Minería, William Leonardo Malaver Camargo, Harol Steven García Cuta

Ingeniería en Automatización

El presente documento describe el proceso de diseño de una máquina extrusora automática, para la fabricación de retacados de arcilla empleados en la industria de la minería. Este diseño, se basó en la integración de componentes mecánicos, electrónicos y eléctricos, que en conjunto facilitarán el funcionamiento de la máquina en modo manual y automático, además de permitir la supervisión y la monitorización del proceso a través de sensores y pantallas HMI. Con este diseño, se automatiza un proceso productivo que, en la actualidad, no cumple con las necesidades de calidad que demanda el sector minero. En la primera parte del …

Optimal Configuration Of Remanufacturing Supply Network With Return Quality Decision, Mohannad Radhi, Guoqing Zhang

Mechanical, Automotive & Materials Engineering Publications

No abstract provided.

An Energy Cube Project For Teaching Engineering Design Process, Fionnuala Farrell, Shannon Chance, Micheal O'Flaherty

Conference papers

This year, the College of Engineering and the Built Environment at our institute inaugurated a new Common First Year design project module that helps inform students in the selection of a specific engineering discipline. Each student, prior to selecting their bachelor’s specialism, completes three group-based design projects: a bridge design project (to familiarise students with civil and structural engineering), a RoboSumo project (involving robotics, programming, electrical and electronics engineering), and an Energy Cube project (introducing fundamentals of mechanical, manufacturing and design, and building services engineering). This paper focuses on how the engineering design process was taught via the Energy Cube. …

Creation And Analysis Of Checklists To Improve Raquet Stringing Performance In Tennis Warehouse, Alston S. Nguyen

Industrial and Manufacturing Engineering

Tennis Warehouse has a need to increase the supply of strung racquets and man hours to complete these strung racquets over the course of a year. That is, the demand can be increased by up to 4 times its average load during certain hectic parts of the year (professional tournaments, holidays, and competitive seasons). Not meeting this demand can lead to upset customers, unnecessary waste and replacing of rushed items and shipping costs, and a discouraged customer service representative workforce. The objective of this project is to use a set of checklists to address this problem and attempt to increase …

Performance Metric For Powder Feeder Systems In Additive Manufacturing, Venkata Sivaram Bitragunta, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In blown powder Direct Metal Deposition (DMD) process, parts are built by adding metal powder on the melt pool created by the laser system. At low feed rates powder feeder systems have perturbations. The study focused on relationship between the perturbation frequencies by inherent powder feeder designs and its impact on deposition quality. Performance metric determine the relation between perturbations in the powder flow and quality of the deposit. To determine performance metric, various powder feeder designs were analyzed. Perturbation frequencies were introduced to the disk feeder design. The quality of the deposit was determined by the surface roughness of …

Depth Of Cut Monitoring For Hybrid Manufacturing Using Acoustic Emission Sensor, Haythem Gaja, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Metal Deposition LMD is a hybrid manufacturing process consist of a laser deposition system combined with a 5-axis CNC milling system. During laser deposition many parameters and their interaction affect the dimensional accuracy of the part produced, powder flow rate, laser power and travel speed are some of these parameters. Sensing the acoustic emission during milling marching gives feedback information regarding depth of metal being cut subsequent part dimensions, if an error in dimensions is found certain actions, such as remaching, close loop control, or laser remelting can be carried out to correct it. Thus a reliable hybrid manufacturing …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser metal deposition with wire feed is one of the additive manufacturing methods with great scope and robustness. Process parameters plays an important role in controlling the process and obtaining an ideal manufactured part. Simulations tools are highly essential in determining the ideal parameters and melt pool conditions. The current work is a transient 3D model of wire feed additive manufacturing which realizes the heat transfer and fluid flow behavior of the process with varying laser power and power density. The model was programmed in Python and a 1 KW Gaussian beam fiber laser was used to conduct experiments. The …

Freeform Extrusion Fabrication Of Titanium Fiber Reinforced Bioactive Glass Scaffolds, Albin Thomas, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Although implants made with bioactive glass have shown promising results for bone repair, their application in repairing load-bearing long bones is limited due to their low fracture toughness and fairly fast degradation response in vivo. In this paper, we describe our investigation of freeform extrusion fabrication of silicate based 13-93 bioactive glass scaffolds reinforced with titanium fibers. A composite paste was prepared with 13-93 bioactive glass filled with titanium fibers (~16 µm in diameter and aspect ratio of ~250) having a volume fraction of 0.4 vol. %. This paste was then extruded to fabricate scaffolds with an extrudate diameter …

Dc-Gain Layer-To-Layer Stability Criterion In Laser Metal Deposition Processes, Patrick M. Sammons, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In Laser Metal Deposition (LMD), a blown powder metal additive manufacturing process, functional metal parts are fabricated in a layer-by-layer fashion. In addition to the in-layer dynamics, which describe how the process evolves within a given layer, the additive-fabrication property of LMD creates a second set of dynamics which describe how the process evolves from layer-to-layer. While these dynamics, termed layer-to-layer dynamics, are coupled with both the in-layer dynamics and the process operating conditions, they are not widely considered in the modeling, process planning, or process control of LMD operations. Because of this, seemingly valid choices for process parameters can …

Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., > 50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …

Effects Of Temperature On Aqueous Freeform Extrusion Fabrication, Jie Li, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An experimental study was conducted to investigate the effect of temperature on ceramic parts produced by paste extrusion based additive manufacturing followed by sintering. A computer-controlled gantry system equipped with a piston extruder was used to extrude aqueous alumina paste. The system includes a temperature control subsystem that allows for freeform extrusion fabrication inside a low-temperature (<0°C) chamber. It can also be used for fabricating parts on a hot plate at ambient or higher temperatures (≥20°C). Test specimens were fabricated from aqueous aluminum pastes at -20°C in the low-temperature chamber and also on the hot plate at 40°C. The minimum angles achievable by these two processes for part fabrication, without use of support material, were compared. Also compared were the relative density and mechanical properties of the parts obtained after sintering. Microstructures were examined via scanning electron microscopy in order to obtain a deeper understanding of the effect of fabrication temperature.

A Microstructure And Hardness Study Of Functionally Graded Materials Ti6al4v/Tic By Laser Metal Deposition, Jingwei Zhang, Yunlu Zhang, Frank W. Liou, Joseph William Newkirk, Karen M. Brown Taminger, William J. Seufzer

Materials Science and Engineering Faculty Research & Creative Works

Crack free functionally graded material (FGM) Ti6Al4V-TiC has been fabricated by laser metal deposition (LMD) using TiC and Ti6Al4V powder which were premixed for different ratios. This study focuses on the influence of laser processing parameters and TiC compositional distribution on microstructure, Vickers hardness and phase. The microstructure is analyzed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and hardness tests. Primary carbide, eutectic carbide and unmelted carbide are found in the deposit area. When laser power increased, the primary and secondary dendrite arm spacing increased. The laser power and scanning speed did not influence the Vickers hardness distribution significantly.

Direct Laser Deposition Of Ti-6al-4v From Elemental Powder Blends, Lei Yan, Xueyang Chen, Wei Li, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A thin-wall structure composed of Ti-6Al-4V has been deposited using direct laser deposition (DLD) from blended Ti, Al, and V elemental powders. The microstructure and composition distribution along the build height direction were intensively investigated using optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), and Vickers hardness testing. The microstructures of the as-deposited Ti-xAl-yV were studied using EDS to determine appropriate weight percentage for Al and V in the blended powders before mixing. The effects of laser power and laser transverse speed on the microstructure were investigated and optimized laser processing parameters were concluded.

Modeling Of Powder Bed Processing -- A Review, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Many models have been developed to model powder beds and these methods can be implemented to model a powder bed for Selective Laser Sintering, Selective Laser Melting and any other technique of additive manufacturing which uses powder beds. Two of the main systems are the Discrete Element Method (DEM) and the Geometric Method. The purpose of this paper is to analyze each of the methods. It will first highlight how each of the models creates the powder bed. The next aspect reviewed is the computational time and its causes. And lastly, each of the methods will be examined for their …

Solid Freeform Fabrication Of Transparent Fused Quartz Using A Filament Fed Process, J. Luo, L. J. Gilbert, C. Qu, B. Morrow, Douglas A. Bristow, Robert G. Landers, J. Goldstein, A. Urbas, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Glass is a critical material for many scientific and engineering applications including optics, communications, electronics, and hermetic seals. Despite this technological relevance, there has been minimal research toward Additive Manufacturing (AM) of glass, particularly optically transparent glass. Additive Manufacturing of transparent glass offers potential advantages for lower processing costs for small production volumes, increased design freedom, and the ability to locally vary the optical properties of the part. Compared to common soda lime glass, fused quartz is better for AM since it has lower thermal expansion and higher index homogeneity. This paper presents a study of additive manufacturing of transparent …