Engineering Commons^™

Comparison Of Popular Three-Dimensional Printing Materials For Oral And Maxillofacial Surgical Guidance Model, Mohammad Adhitya, Sunarso Sunarso, Abdul Muis

Journal of Dentistry Indonesia

The application of three-dimensional (3D) models in the medical field has become popular. However, the accuracy of 3D models for surgical guidance varies among different materials and 3D printing technologies, such as printing machine usage. Objectives: This study aims to obtain more information about the effect of three different materials printed using a fused deposition material printer from the same digital data source. This study also aims to compare, analyze, and test the materials’ ability. Methods: Each of the filament materials (acetylbutane stearate [ABS], polylactic acid [PLA], and high-impact polystyrene [HIPS]) are printed at two infill densities, their weight, volume, …

Spectral Absorption Coefficient Of Additive Manufacturing Materials, Nicholas J. Wallace, Matthew R. Jones, Nathan B. Crane

Faculty Publications

Active thermography techniques are of interest for quality assurance of additive manufacturing processes. However, accurate measurements of thermophysical properties of materials are required to successfully implement active thermography. In particular, the spectral absorption coefficient of materials commonly used in additive manufacturing must be known to accurately predict the spatial distribution of thermal energy generated from absorption of power emitted by a laser or pulsed flash lamp. Accurate measurements of these optical properties are also needed to develop greater understanding of additive manufacturing processes that rely on radiative heat transfer to fuse powders. This paper presents spectral absorption coefficient measurements and …

Thermo-Fluid Characterizations Of The Powder-Bed Fusion Additive Manufacturing Processes Using Laser And Electron Beam, M Shafiqur Rahman

University of New Orleans Theses and Dissertations

The powder-bed fusion (PBF) process is a subdivision of Additive Manufacturing (AM) technology where a heat source at a controlled speed selectively fuses regions of a powder-bed material to form three-dimensional (3-D) parts. Two of the most effective PBF processes are selective laser melting (SLM) and electron beam additive manufacturing (EBAM), which can fabricate full-density metallic parts in a layer-by-layer fashion. In this study, thermal behavior and melt-pool dynamics in the PBF process are investigated by developing 3-D multiphysics-based thermo-fluid models for both SLM and EBAM, containing Ti-6Al-4V alloy as a powder-bed material. The laser and electron beams are modeled …

A Bibliometric Analysis Of Minimum Quantity Lubrication As A Sustainable Approach, Shrikant U. Gunjal Mr., Sudarshan B. Sanap Dr.

Library Philosophy and Practice (e-journal)

Environment-friendly machining methods are being focused widely across the research areas concerning the consequences and challenges of the traditional methods. Flood lubrication technique which is aggressively being implemented, targeting better machining attributes of the end product. However, the devastating effects of the flood lubrication technique are causing harmful consequences to the environment majorly and the machining operator therein. Minimum quantity lubrication (MQL) which is also called Near-dry machining (NDM) is the most attributed cooling and lubrication approach which justify the sustainable requirements of the development; as it implies only 50-150 ml/hr cutting fluid under consideration. The present article presents the …

Mechanics Of The Solid-State Bonding Under Severe Thermomechanical Processes, Xue Wang

Doctoral Dissertations

Friction stir welding (FSW) has found increased applications in automotive and aerospace industries due to its advantages of solid-state bonding, no fusion and melting, and versatility in various working conditions and material combinations. The extent and quality of the solid-state bonding between workpieces in FSW is the ultimate outcome of their industrial applications. However, the relationship among processing parameters, material properties, and bonding extent and fidelity remains largely empirical, primarily because of the lack of the mechanistic understanding of (1) tool-workpiece frictional behavior, and (2) bonding formation and evolution.

In this dissertation, to study the underlying mechanism of tool-workpiece frictional …

Design, Fabrication, And Reliability Effects Of Additively Manufactured First Level Compliant Interconnects For Microelectronics Application, Tumininu David Olatunji

Graduate Theses and Dissertations

Semiconductor packaging and development is greatly dependent on the magnitude of interconnect and on-chip stress that ultimately limits the reliability of electronic components. Thermomechanical related strains occur because of the coefficient of thermal expansion mismatch from different conjoined materials being assembled to manufacture a device. To curb the effect of thermal expansion mismatch between conjoined parts, studies have been done in integrating compliant structures between dies, solder balls, and substrates. Initial studies have enabled the design and manufacturing of these structures using a photolithography approach which involves a high number of fabrication steps depending on the complexity of the structures …

Vibration Behavior In Modulated Tool Path (Mtp) Turning, Ryan William Copenhaver

Doctoral Dissertations

This project studies the process dynamics and surface finish effects of modulated tool path (MTP) turning. In MTP turning, a small amplitude (typically less than 0.5 mm), low frequency oscillation (typically less than 10 Hz) is superimposed on the feed motion by the machine controller to intentionally segment the traditionally long, continuous chips. The basic science to be examined is the vibration behavior of this special case of interrupted cutting, which is not turning because the chip formation is intentionally discontinuous and is not milling because the time-dependent chip geometry is defined by the oscillatory feed motion, not the trochoidal …

Mono And Multi-Objective Optimization And Modeling Of Machining Performance In Face Milling Of Ti6al4v Alloy, Al Mazedur Rahman

Theses and Dissertations

Titanium alloys are extensively used in numerous industries like aerospace, automotive, military, etc., due to their exclusive characteristics. But machining these alloys has always been challenging for manufacturers. This research investigates the effect of radial depth of cut on cutting forces, tool life, surface roughness (Ra), and material removal rate (MRR) during face milling of Ti6Al4V alloy. It also aims to perform mono and multi-objective optimization of response characteristics to determine the optimal input parameters, namely cutting speed, feed rate, and radial depth of cut. Taguchi method and analysis of variance (ANOVA) have been used for mono-objective optimization, whereas Taguchi-based …

A.C. Moyer Eye-Cap Manufacturing, Thais Bertolus, Alexa Steidl, Hana Welsh, Jarod Kinney, Maya Willis

Mechanical Engineering

A.C. Moyer company has been making eye caps as a family business since 1947. Eye caps are a product used during the embalming process. Currently the machines being used to produce the eye caps are outdated and unsafe. We are a team of 5 mechanical engineering students tasked with either designing new machines or updating the existing machines to make the manufacturing process more efficient, automated, and safer. This document describes the design process, provides background, relevant research, establishes project objectives, and defines plans for project implementation.

Modeling And Analysis For Unit Cell Size, Material Anisotropy And Material Imperfection Effects Of Cellular Structures Fabricated By Powder Bed Fusion Additive Manufacturing., Yan Wu

Electronic Theses and Dissertations

Cellular structures are networks of interconnected struts or walls with porosities and are widely found in many natural load-bearing structures such as plants and bones. Cellular structures offer unique functional characteristics such as high stiffness to weight ratio, tailorable heat transfer coefficient, and enhanced mechanical energy absorption, which makes them highly attractive in various engineering disciplines such as biomedical implants, electrodes, heat exchangers, and lightweight structures. There exists an abundance of literatures that have investigated various mechanical properties of various cellular structures such as Poisson’s ratio, elastic modulus, ultimate strength, yield strength, and failure characteristics. Based on the classic cellular …

Measurement And Analysis Of Pressure Profile For Nozzle Based Single Screw Extrusion Systems, Jake Dvorak

Masters Theses

Most large-scale material-extrusion (MatEx) AM systems utilize a single screw extruder. Simulating flow rate and operating pressures of extrusion systems is notoriously difficult without resorting to full finite element analysis due to the phase change and non-Newtonian nature of relevant polymers. This study characterized two machines of interest: a Big Area Additive Manufacturing (BAAM) system and a Randcastle Microtruder. A custom nozzle adapter was fabricated to gather pressure data within the nozzle and mimic the die design of the BAAM on the Microtruder system. Several theories were tested for overall machine output and max pressure. Feed and compression zone theories …

Improvement Of Light Intensity And Efficiency Of N-Zno/Nio/P-Gan Heterojunction-Based White Light Emitting Diodes Using Micro-/Nanolens Array, Apurba Adhikary, Md Shamim Ahsan, Md Mahbub Hossain, Md Bipul Hossain, S. H. Shah Newaz, Farid Ahmed, Ik-Bu Sohn

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Our study proposes a technique to enhance light extraction efficiency of light emitting diodes (LEDs) by incorporating various micro-/nanolens arrays (MNLAs) on the substrate layer, which in turn increases the external quantum efficiency (EQE) of the LEDs. To simulate the LEDs, we utilized the finite difference time domain method. To achieve a white LED, we inserted a thin layer of NiO at the interface between the n-type ZnO and the p-type GaN. The basic n-ZnO/NiO/p-GaN heterojunction-based LED exhibited an EQE of 10.99% where the effective refractive index of the LED structure was 1.48. The EQE was further increased by engraving …

Grow Local Manufacturing Along Us/Mexico Border Region For An Integrated Supply Chain In The Post Covid-19 Era, Jianzhi Li

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The current coronavirus disease pandemic, plus the strong movement of manufacturing reshoring, provide a unique opportunity for many US regions to grow local manufacturers. This technical note attempts to review the current situation and trend in US manufacturing. We then discuss challenges and necessary steps, such as asset mapping, required to grow local suppliers. Suggestions are then made to support growing local suppliers along the US/Mexico border region.

Evaluation Of A Bulge Reduction Technology For Corrugated Fiberboard Containers Under Static Compression, Daan Peleman, Jay Singh, Koushik Saha, S. Roy

Journal of Applied Packaging Research

This research examines the effect of top-to-bottom static compression load on the bulge of RSC containers. The study compares a control regular slotted container (RSC) constructed with corrugated fiberboard to tape-reinforced designs. The bulge reduction, achieved using various tape placements and conditioning environments, were measured. Currently, no research on the effect of reinforcement tape towards reduction in the out-of-plane displacement (bulging) of the corrugated fiberboard panels has been undertaken. Samples related to four different container designs, varying by presence, quantity and the position of the reinforcement tape on the vertical panels, were tested and analyzed. The study involved the use …

Numerical Modeling And Conjugate Heat Transfer Analysis Of Single U-Tube Vertical Borehole Heat Exchangers, Talha Khan

FIU Electronic Theses and Dissertations

The primary purpose of this thesis was to develop a design for improving the efficiency of the vertical type single u-tube borehole heat exchanger. A thorough literature review of the various existing analytical and numerical models of the borehole heat exchanger (BHEs) was performed and numerical modeling of the BHE was conducted to solve the conjugate heat transfer problem in the BHE in 3D using ANSYS Fluent 2019 R1. A comparison between the results obtained using various mesh sizes, types, different turbulence models showed the independence of the parameters on the numerical simulation results.

From the numerical simulation, it was …

A New Method Of Statcom Controlling For Harmonic Mitigation And Power Factor Correction, Doha Jdeed

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

This paper presents a control algorithm of 3ph STATic synchronous COMpensator (STATCOM). The algorithm depends on the accurate reference currents extraction from only the nonlinear load current spec-trum in frequency domain using Fast Fourier Transfer (FFT). Then the determined harmonics and reactive components of load current are added together to form the compensating reference signals, the PI controllers then generate signals which control the Pulse Width Modulation (PWM) method. The simulation of the study is carried out under MATLAB/Simulink environment to show the usefulness of this control algorithm with nonlin-ear dynamic loads. It determines exactly the phase shift between the …

Study On The Viability Of Preparing Plaster Molds For Rapid Prototyping Of Complex Ceramic Parts Using The Lost Pla Method, Shelton F. Fowler Iv

Honors College Theses

In the field of metal casting, cast parts often require an internal cavity to be made to meet design requirements. Frequently, these interior surfaces are not manufacturable through standard machining processes, and even when possible, they would most likely involve expensive and time-consuming operations. In order to avoid these machining costs, expendable ceramic or sand cores are manufactured and placed into the mold to allow the direct casting of complex internal geometries. This research seeks to use relatively inexpensive plastic 3D printing technology and the lost PLA casting process for the production of low-cost and rapidly producible ceramic cores. A …

Final Design Review Report: The Underdogs, Parker Johnson, Jack Montgomery, Katherine Thomas

Mechanical Engineering

Aspen is a three-legged dog with mobility issues from Berkeley, California. She was hit by a car and her rear left leg was amputated at the hip. Robin Swanson, Aspen's owner, and her friend, Audrey Beil, are the sponsors for this project. Jack Montgomery, Katherine Thomas, and Parker Johnson, “The Underdogs”, are tasked with helping Aspen regain some of her mobility and the ability to go on walks. Research was done into the problem by talking with the sponsors and looking into existing products, designs, and patents. This document, the Final Design Review Report, outlines the background information, problem specification, …

2 Degree Of Freedom Robotic Leg, Oded Tzori, Henry Terrell, Adan Martinez

Mechanical Engineering

Professor Xing, an assistant professor at Cal Poly, proposed the 2 DOF Robotic Leg project for this quarter’s senior project class. The project is to build a robotic leg attached at the hip to a stand, which will be used as a teaching tool and eventually help develop Cal Poly’s very own robotic quadruped. Since this project has multiple uses after its completion, there are multiple customers that it must perform well for: the Cal Poly Mechanical Engineering (ME) Department, the ME Lab instructors, and the students. The Scope of Work (Sections 2 & 3) is composed of 2 main …

Modulating Mechanical Properties Of Polymer Composites Via Colloidal Particle Reinforcement, Yusheng Guo

LSU Master's Theses

Additive manufacturing allows the rapid process of complex objects with excellent design flexibility. However, the products often exhibit poor mechanical properties when pure polymer is applied as printable material. In this work, we demonstrate that printability of polymer can be dramatically improved when particle filler is added to form reinforced polymer composites. Furthermore, the interaction between filler and polymer matrix leads to the enhancement in mechanical properties of the printed product. The material reinforcement induced by addition of fillers enables the wide application of polymer composites to print structures with unique features. In the printing of silica-reinforced pNIPAM composite, we …

Characterization And Performance Of Minimum Quantity Lubricants In Through-Tool Drilling, Amla Patil, Jay Raval, Tim Bangma, Immanuel Edinbarough, Bruce Tai, David Stephenson, Suleiman Obeidat, Wayne Nguyen Hung

Manufacturing & Industrial Engineering Faculty Publications and Presentations

This study characterized airborne microdroplet diameters and size distribution from two commercially available lubricants A and B for internal minimum quantity lubrication (MQL). The effects of air pressure, oil channel size, physical properties of lubricants on the resultant microdroplets and through-tool MQL drilling performance were studied. Airborne microdroplet diameters were highly sensitive to the coolant channel sizes and air pressure. Cluster method was used to divide microdroplets into smaller clusters for comparison. Experimental data show that the average airborne microdroplet of lubricant B was larger than that of lubricant A at different air pressures and channel sizes. The contact angle …

Impact Of Sintering Time And Temperature On Mechanical Properties In Projection Sintering Of Polyamide-12, Justin Nussbaum, Taranjot Kaur, Julie Harmon, Nathan B. Crane

Faculty Publications

In powder bed fusion additive manufacturing (AM), the fusing process is temperature and time dependent. However, little work has been done to understand how different processing temperatures and times might impact the mechanical properties at longer sintering times than are typical in laser sintering (LS) systems. Prior results with projection sintering have shown that heating for longer times (>1s) improves part toughness compared to laser sintering. In this work, Large Area Projection Sintering (LAPS) is used to sinter entire layers of material simultaneously over the course of a few seconds with spatial control of layer temperature. This work evaluates …

Design Of A Methanol Reformer For On-Board Production Of Hydrogen As Fuel For A 3kw High-Temperature Proton Exchange Membrane Fuel Cell Power System, Vladimir Gurau, Adedayo Ogunleke, F. Strickland

Department of Manufacturing Engineering Faculty Research and Publications

The method of Computational Fluid Dynamics is used to predict the process parameters and select the optimum operating regime of a methanol reformer for on-board production of hydrogen as fuel for a 3 kW High-Temperature Proton Exchange Membrane Fuel Cell power system. The analysis uses a three reactions kinetics model for methanol steam reforming, water gas shift and methanol decomposition reactions on Cu/ZnO/Al2O3 catalyst. Numerical simulations are performed at single channel level for a range of reformer operating temperatures and values of the molar flow rate of methanol per weight of catalyst at the reformer inlet. Two operating regimes of …

An Affordable And Portable Palpable System For Sensing Breast Tissue Abnormalities, Cody J. Clarke

Montview Journal of Research & Scholarship

Due to the high cost of equipment and lack of trained personnel, manual palpation is a preferred alternative breast examination technique over mammography. The process involves a thorough search pattern using trained fingers and applying adequate pressure, with the objective of identifying solid masses from the surrounding breast tissue. However, palpation requires skills that must be obtained through adequate training in order to ensure proper diagnosis. Consequently, palpation performance and reporting techniques have been inconsistent. Automating the palpation technique would optimize the performance of self-breast examination, optimize clinical breast examinations (CBE), and enable the visualization of breast abnormalities as well …

Parametric Study Of The Cutting Process And Surface Formation During Elliptical Vibration Assisted Single Point Cutting, Nikolai D. Farrus

Electronic Thesis and Dissertation Repository

Elliptical vibration cutting has enabled the fabrication of numerous functional surfaces such as optical quality surface finishes, micro/nano surface texturing, and improved cutting force reduction on ferrous and other hard‑to‑cut materials. This wide range of capabilities comes from the high‑frequency elliptical vibrations produced at the tool tip, ultimately introducing discontinuous contact between the cutting tool and workpiece. However, despite the relative use of this technology, there has been limited investigation on the overarching parametric influence that its cutting parameters have on process outcomes such as cutting forces and surface roughness formation.

The current thesis addresses this research gap with the …

Formula Sae Monocoque Chassis Development, Kc Egger, Brian Ford, Kyle Nagao, Neal Sharma, Donovan Zusalim

Mechanical Engineering

Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis.

A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque …

Application Of Optimized Laser Surface Re-Melting Process On Selective Laser Melted 316l Stainless Steel Inclined Parts, Jafar Ghorbani, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Lower surface quality of selective laser melting (SLM) manufactured parts remains to be a key shortcoming particularly for high performance functional components. In this paper, the authors utilized Box–Behnken methodology to explore the effect of laser surface re-melting process parameters. The process parameters are:laser power, laser exposure time, laser point distance, and shell layer thickness. The experiments were conducted using Renishaw AM-250 machine. SLM manufactured parts with inclination of 45˚ up-skin were treated with a given surface roughness using laser surface re-melting (LSR). The optimization of process parameters was conducted using response surface methodology and the validation tests was carried …

Experimental Study Of Graphene Energy Absorbing Layer In Femtosecond Infrared Laser Assisted Bioprinting, Chaoran Dou

Theses and Dissertations

The bioprinting, as a new branch of additive manufacturing, already shown its potential in organ transplantation, medicine develop and personalized medicine. There are three types of bioprinting: droplet based bioprinting, extrusion based bioprinting and laser assisted bioprinting (LAB). Compared with other types of bioprinting, the LAB is the only bioprinting method that does not have a nozzle, which gives it the ability to print high viscosity bioink. The LAB also enjoys higher resolution and cell viability than other methods.

The bubble/jet formation process is the most important process for the LAB, which deposits the bioink to the substrate. To utilize …

Dynamic Analysis And Fabrication Of A Bi-Stable Structure Designed For Mems Energy Harvesting Applications., Masoud Derakhshani

Electronic Theses and Dissertations

Thanks to the rapid growth in demand for power in remote locations, scientists’ attention has been drawn to vibration energy harvesting as an alternative to batteries. Over the past ten years, the energy harvesting community has focused on bistable structures as a means of broadening the working frequency range and, by extension, the effective efficiency of vibration-based power scavenging systems. In the current study, a new method is implemented to statically and dynamically analyze a bistable buckled, multi-component coupled structure designed specifically for low-frequency vibration energy harvesting systems in both macro and MEMS-scale sizes. Furthermore, several micro-fabrication steps using advanced …

Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang

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

Additive Manufacturing (AM) has been a promising manufacturing technology in industrial applications and gained a massive amount of attention from researchers all over the world. Directed Energy Deposition (DED) is an AM process in which focused thermal energy is used to fuse materials by melting as they are deposited. One of the most significant challenges involved in current metal AM processes is improving repeatability and consistency. Substantial effort has already been invested in this area of research.

In this dissertation, a milling tool not only played a role in subtractive manufacturing but also acted as a method of monitoring the …