Mechanical Engineering Commons^™

Model-Based Predictive Controller Design, Soheil Sadeghi

Graduate Research Papers

Process control in industries is becoming more critical due to demands on reducing consumed energy, reducing cost, and improving system efficiency and performance. In this work, a well-developed, model-based controller is introduced and implemented in one of the most common processes in the industry. Model Predictive Controller (MPC) has been studied for ten years, but recently has emerged into small industries as the number of current applications grows. These controllers need a process model in the forms of transfer functions, step response, or state-space. Although obtaining a process model can be a cumbersome task, it is worth having it (the …

Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt

College of Graduate Studies: Theses & Dissertations

Fused silica is widely used for investment casting shell molds. Fused silica shells are discarded after being used for casting one time. This is due to the transformation of fused silica to beta cristobalite above 1652℉ (900℃). To reduce cost and waste of investment casting foundries, this study is exploring a method to inhibit transformation of fused silica and reclaim it from high temperature investment casting shells. This research has employed firing to minimalize fused silica transformation to cristobalite. The phase transformation is minimalized due to sintering and coarsening of the particles during firing. Coarsening reduces surface area to volume …

Effect Of Feedrate, Depth Of Cut, Tool Material, And Toolpath On Dimensional Accuracy And Surface Roughness Of Milled Cfrp, Assem Hesham Almadani

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis investigates the effect of different factors on Carbon Fiber Reinforced Polymers (CFRP) milling, like feedrate, tool material, and cutting speed. CFRP offers excellent material properties, which led to the increase of the material in today's manufacturing industry. CFRP offers up to 2.25 times steel's modulus of elasticity at about a fifth of the weight and excellent thermal properties, which allow the use of this material in applications with high heat like automobiles. Many industries have implemented the use of CFRP in their applications, like airplanes and automobiles, which lead to a decrease in weight and increase in strength. …

Prediction Of Tensile Behaviors Of L-Ded 316 Stainless Steel Parts Using Machine Learning, Israt Zarin Era

Graduate Theses, Dissertations, and Problem Reports (ETD)

Directed energy deposition (DED) is a rising field in the arena of metal additive manufacturing and has extensive applications in aerospace, medical and rapid prototyping. The process parameters, such as laser power, scanning speed and specimen height, play a great deal in controlling and affecting the properties of DED fabricated parts. Nevertheless, both experimental and simulation methods have shown constraints and limited ability to generate accurate and efficient computational predictions on the correlations between the process parameters and the final part quality. In this work, a data driven machine learning model XGBoost has been built and applied to predict the …

In-Situ Process Monitoring For Metal Additive Manufacturing (Am) Through Acoustic Technique, Md Shahjahan Hossain

College of Graduate Studies: Theses & Dissertations

Additive Manufacturing (AM) is currently a widely used technology in different industries such as aerospace, medical, and consumer products. Previously it was mainly used for prototyping of the products, but now it is equally valuable for commercial product manufacturing. More profound understanding is still needed to track and identify defects during the AM process to ensure higher quality products with less material waste. Nondestructive testing becomes an essential form of testing for AM parts, where AE is one of the most used methods for in situ process monitoring. The Acoustic Emission (AE) approach has gained a reputation in nondestructive testing …

Development Of In-Situ Radiometric Inspection Methods For Quality Assurance In Laser Powder Bed Fusion, Cody S. Lough

Doctoral Dissertations

“Laser Powder Bed Fusion (LPBF) metal Additive Manufacturing (AM) fabricates 3D metal parts layer-by-layer. The process enables production of geometrically complex parts that are difficult to inspect with traditional methods. The LPBF parts experience significant geometry driven thermal variations during manufacturing. This creates microstructure and mechanical property inhomogeneities and can stochastically cause defects. Mission critical applications require part qualification by measuring the defects non-destructively. The layer-to-layer nature of LPBF permits non-intrusive measurement of radiometric signals for a part’s entire volume. These measurements provide thermal features that correlate with the local part health. This research establishes Optical Emission Spectroscopy (OES) and …

Advance Metallic Reinforcement Of Vat Photo Polymerized Parts, Scott Zinn

UNF Graduate Theses and Dissertations

The metallization or metallic reinforcement of polymer parts has been widely used in industry for several decades. Polymer parts are classically metalized for aesthetics, chemical and thermal resistance, electrical conductivity, and mechanical strength. Metallization has been shown to increase strength of polymer parts when compared to the strength of the bulk material without metallization. Additive manufacturing (AM) techniques that have emerged in the last few decades produce parts with different surface features and chemistry than the typical polymer part produced through injection molding. AM parts are typically weaker than traditionally manufactured parts from the same material due to intrinsic details …

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

This research work was conducted to develop a proposed transparent fluid model to mimic dross formation and dispersion in metal castings during the mold filling process. The major cause for dross formation includes the air entrainment, surface turbulence, and bubbles, which create oxide films inside the molten metal. The oxide films are trapped inside the casting after solidification causing detrimental effects on the mechanical properties of the casting.

The objective of the investigation was to explore the feasibility using phenolic urethane as a transparent fluid material to investigate air entrainment mechanism. The experimentation consists of the following materials: the phenolic …

The Investigation Of The Underlying Microstructure Associated With Fracture Features In 6061 Cold Sprayed Aluminum, Justin White

UNF Graduate Theses and Dissertations

Cold gas dynamic spraying commonly known as cold spray is a process currently used for restoration, re-tolerancing, and application of coatings. With additional resources allocated towards the development of a through process model aimed at predicting the properties of bulk material produced via the Cold Spray process, more lab testing and investigation must be done to capture the effects of the varying microstructure in CS materials. The properties of ultra-fine-grained materials are derived from data collected from coarse grained materials and processes that do not accurately capture the effects as elevated strain rates and ultra-fine-grained materials. The lack of property …

Dry Reforming Of Methane Using Microwave Irradiated Metal Oxide/Coal Char Catalysts, Anthony Carter

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research focuses on the synthesis of both shaped and amorphous powder materials, the combination of these materials with dried Powder River Basin (PRB) coal char, and their reactionary properties with methane and carbon dioxide gasses with conventional and microwave (MW) heating. The first goal of this project was to synthesize shaped micro and nano sized particles with ideal dielectric properties for converting electromagnetic energy into heat and proven capabilities of activating methane. These particles were synthesized via solvothermal, hydrothermal, and co-preceptory treatments alone and onto the surface of dried PRB coal char. PRB is a sub-bituminous, low-ranking coal (LRC) …

Sustainability Assessment Of Direct Energy Deposition (Ded) Based Hybrid Manufacturing Using Life Cycle Assessment (Lca) Method, Faujia Islam

Graduate Theses, Dissertations, and Problem Reports (ETD)

As sustainability has emerged as a highlight for almost every field over the last few decades, the manufacturing field is no exception. Generally, additive manufacturing performs better than traditional manufacturing in terms of sustainability because of its lean energy- and material usage. Previous studies have compared the sustainability performance between traditional and additive manufacturing, but hybrid manufacturing was not focused upon much. In this paper, the life cycle assessment method is used to analyze and compare the energy consumption and environmental impact of direct energy deposition (DED) based hybrid manufacturing and traditional manufacturing “CNC milling” process for a turbine blade. …

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

LSU 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 …

Evaluation Of Mechanical Properties Of Malaysia Local Source Wood For Electric Cruiser Board Applications, Mohamad Rosman Othaman

Student Works (2020-2029)

This research project revolves around the idea to reduce the carbon emission in mitigating the issue of climate change. An idea to introduce the electrical cruiser board by Muhammad Fiqkri Ismail from Universiti Kuala Lumpur with his idea to promote carbon less form of multimodal transportation for users in urban city of Greater Kuala Lumpur leads this research to study the elastic properties of local source woods in Malaysia that could be proposed for this application. The wood is used for the construction of the deck of cruiser board which designed three layers with the cross-ply laminate. Three types of …

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 …

Additive Manufacturing-Enabled Design, Manufacturing, And Lifecycle Performance, Tao Peng, Yi Zhu, Ming Leu, David Bourell

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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 …

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 …

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.

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

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

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.

Data Analysis To Evaluate The Performance Of Breathing Masks Used For Filtering Nano-Level Particles At Manufacturing Sites, Gracia M. Dardano

Honors College Theses

The work performed in this research aims to evaluate the performance of commercially available breathing masks in filtering airborne nanoparticles at manufacturing sites. Nanoparticles are found virtually anywhere, from dust in a worksite to a simple sneeze. Therefore, they pose a substantial threat to human health as their velocity and volatility are high. This research analyzes if current efforts of breathing masks to hinder nanoparticles are effective, especially at manufacturing sites. Data has been collected in order to analyze the behavior of nanoparticles and to measure nanoparticle levels at manufacturing sites and its working environment. Data is statistical in nature …

Fusion-Features And Visual-Dictionary Image Recognition Methods For Apple Classification In Smart Manufacturing, Ahsiah Ismail

Student Works (2020-2029)

Smart manufacturing enables an efficient manufacturing process to optimize production. The optimization is performed through data analytics that requires reliable and informative data as input. Therefore, in this research, two image recognition feature extraction methods namely Curvelet Wavelet-Gray Level Co-occurrence Matrix (CWGLCM) and Fuzzy-Spatial Pyramid Matching (F-SPM) are proposed to provide reliable inputs for vision-based apple classification in smart manufacturing. Feature extraction is one of the major steps that could influent the efficiency of the manufacturing process. The CW-GLCM method is a feature extraction of fusion-features with Decision Tree classifier, while the F-SPM method uses a visual-dictionary based method to …

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 …

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 …