Manufacturing Commons^™

Thermal Resistance Characterization Of High-Voltage Sic Power Module, Landon Lemmons

Mechanical Engineering Undergraduate Honors Theses

Researchers within the University of Arkansas Electrical Engineering Research Department have embarked on a project aimed at enhancing the thermal performance of high-voltage power modules. To aid in the progress of this project, the design, and development of a thermal tester device are needed. The primary objective of this device is to determine the various thermal properties of high-voltage power modules that the electrical engineering department has developed. Additionally, the project aims to facilitate electrical loading tests on power modules and provide researchers with the means to calibrate the power module in terms of thermal load. This project also possesses …

Exploring Methods For Recycling Filament Waste In 3d Printing, Max Rios Carballo

Publications and Research

The goal of the current study is to investigate cutting-edge techniques for recycling filament waste from 3D printing procedures. Appropriate waste management techniques are required to reduce this trash's harmful environmental consequences. The goal of the project is to look at new methods for recycling filament waste in order to minimize disposal and encourage reuse. To acquire data from pertinent papers and research, a thorough literature review methodology was used. The findings show that this issue may be resolved utilizing a variety of recycling techniques, including shredding, melting, and re-extrusion. The type of filament waste and the intended goal will …

Experimental And Numerical Studies On Laser Hot Wire Cladding By A High-Power Direct Diode Laser, Mingpu Yao

Mechanical Engineering Research Theses and Dissertations

Laser hot wire cladding is an advanced surface modification technology. It has been extensively growing during the last decades due to its high deposition rate, good metallurgical bonding between the substrate and clad layer, low dilution ratio, and small heat-affected zone. There are many kinds of lasers widely used in the laser cladding process. The high-power direct diode laser is widely welcomed because of its high energy efficiency, high electro-optic conversion efficiency, low cost, and high reliability. A rectangular-shaped direct diode laser beam combined with hot wire feeding can achieve a lower dilution depth with a uniform fusion line compared …

Airflow Impact Upon Remote Laser Welding Quality, Baixuan Yang

Mechanical Engineering Research Theses and Dissertations

Laser induced plasma-plume and condensed particles attenuate the laser beam energy, resulting in keyhole instability and lacking penetration. There are various airflow devices that are currently used in both industrial and laboratory laser welding settings to suppress the detrimental effect of plasma plume and hot spatters. A systematic experimental and numerical study is presented in this dissertation that investigates different external airflow effects on the remote laser welding process used in automotive manufacturing applications.

The vertical airflow impact on the remote laser welding was first studied experimentally. The airflow velocity profiles of a coaxial vertical flow device were measured using …

Geometrically Complex Planar Heat Exchangers, Derli Dias Do Amaral Junior, Jose Lage

Mechanical Engineering Research Theses and Dissertations

In this study, geometrically complex planar heat exchangers, designed in line with the Constructal Law and operating at steady-state, are investigated numerically. The work is divided into two parts, one focusing on diffusion heat transfer in a rectangular plane and another on conjugate diffusion-convection heat transfer in a circular plane heat exchanger.

In the first part, a heat generating rectangular solid volume made of a low conductivity material is cooled through a small, isothermal side-section of the domain. The diffusion cooling process is improved by distributing within the heat generating material a fixed amount of a high conductivity material. The …

Anisotropic Plasticity Modeling Of Thin Sheets And Its Application To Micro Channel Forming Of Steel Foils, Jie Sheng

Mechanical Engineering Research Theses and Dissertations

Thin sheet metals and ultrathin metal foils produced by industrial rolling processes are textured polycrystalline materials and their mechanical behaviors may depend strongly on the orientation of applied loading. Consideration of such plastic anisotropy in advanced modeling of these materials is of the paramount importance in designing optimal manufacturing processes for automotive and other applications using finite element methods. This research addresses several critical issues in anisotropic plasticity modeling and its applications in analyzing micro channel forming of ultrathin stainless-steel foils. An experimental study has first been carried out on the accuracy and sensitivity of measuring the plastic strain ratios …

Adjustable Height Pedestal Grinder Stand, Josef Zagorski, Zachary Wedel, Michael Sitar, Daniel Zevenbergen

Mechanical Engineering

Pedestal grinders are one of the most common machines found in machine shops today. The current industry standard for mounting a grinder is on a fixed single pillar, cast iron pedestal. A fixed pedestal allows for no vertical adjustment for shop users of different sizes and is a safety hazard. This report further defines this problem and proposes an iterative design process to meet the needs and wants of the customer. The adjustable-height pedestal grinder stand Senior Project team used this problem and design process to successfully complete the project within the allotted time. The first major deliverable and milestone …

Rehology And Electrical Conductivity Of Particulate Composites In Additive Manufacturing, Bin Xia

Mechanical Engineering Research Theses and Dissertations

Extrusion-based multi-functional additive manufacturing (AM) has been a rapidly developing area in AM recently. Particulate composites are widely used in this area to provide different functionalities with different types of particulate additives. However, there is no systematic understanding of the behavior of particulate composites during extrusion (especially in small nozzles) or of their properties once deposited in the build. This work investigates the properties of the type of particulate composites usually used in additive manufacturing, composed of a polymer matrix material and particulate additives within the micrometer scale. The focus is on the material rheology in the nozzle/capillary (for the …

Utilizing The Product Development Process To Bring An Idea From Concept To Production, Sydney Ferguson, Jackson Sneed

Honors Theses

The purpose of this thesis is to document and discuss the five-stage product development process starting with defining a problem and resulting in manufacturing a final product for sale as it was implemented in the Portable Fire Pit Center for Manufacturing Excellence Senior Capstone Project. This project was carried out over the course of the Fall 2019 and Spring 2020 semesters by a team consisting of three Undergraduate Mechanical Engineering majors and two Undergraduate Accountancy majors. The ultimate goal of the project was to carry out a full production run of the Portable Fire Pit outputting fifteen units meeting retail …

Development Of A Robotized Laser Directed Energy Deposition System And Process Challenges, Meysam Akbari

Mechanical Engineering Research Theses and Dissertations

Metal additive manufacturing (AM) is a disruptive technology, enabling fabrication of complex and near net shaped parts by adding material in a layer-wise fashion. It offers reduced lead production time, decreased buy-to-fly ratio, and repair and remanufacturing of high value components. AM processes are finding applications in many industrial sectors such as aerospace, automotive, biomedical and mold tooling. However, beside tremendous advantages of AM, there are still some challenges that prevent the adoption of this technology into high standard applications. Anisotropy and inhomogeneity in mechanical properties of the as-built parts and existence of pores and lack-of-fusion defects are considered as …

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. …

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 …

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 …

Swagelok's Hand Tube Bender, Chapin Hutama, Seth Bills, William Mcconnell, Tyler Brown

Williams Honors College, Honors Research Projects

In our project, we are assigned to develop a hand tube bender that is able to bend medium, high pressure, and standard 1/4” and 3/8” tubing. The bender also shall be capable of being used with two hands without the aid of a bench vise and have provisions for use in a bench vise for convenience. The bender shall not damage the tube during bending and induce a maximum of 8% ovality in the bent tubing. In addition, the cost of the bender shall be less than the existing hand tube bender and be resistant to rusting from ordinary use. …

Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu

Mechanical Engineering

The metallic additive manufacturing process known as selective laser melting requires highly spherical, normally distributed powder with diameters in the range of 10 to 50 microns. Previous observations have shown a degradation in powder quality over time, resulting in unwanted characteristics in the final printed parts. 21-6-9 stainless steel powder was used to fabricate test parts, with leftover powder recycled back into the machine. Powder samples and test specimens were characterized to observe changes across build cycles. Few changes were observed in the physical and mechanical properties of the specimens, however, there were indications of chemical changes across cycles. Potential …

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 …

Transcatheter Heart Valve Subassembly Device, Adam Aslam, Matthew Bezkrovny, Daniel Degree

Mechanical Engineering

No abstract provided.

The Collapsible Trailer: Design And Manufacture, Robert Hobson

Biomedical Engineering

No abstract provided.

Effect Of Residual Thermal Stresses On Fracture Behavior And Mechanical Properties Of Al Sub 2 O Sub 3/Ni Cermets, Guo Jin Li, Da Ming Chen, Xiao Xian Huang, Jing Kun Guo

Faculty Publications

Effect of residual thermal stresses on fracture behavior and mechanical properties of Al₂O₃/Ni cermets was qualitatively explained by using theory on residual thermal stresses. When Ni particles are located within Al₂O₃ grains or Ni content is relatively low, tensile stresses are exerted at Al₂O₃-Al₂O₃ grain boundary. While fracturing, intergranular fracture is easily produced. When Ni particles are dispersed at Al₂O₃ grain boundary or Ni content is relatively high, compressive stresses are exerted at Al₂O₃-Al₂O₃grain boundary. …