Manufacturing Commons^™

Development Of A Low Cost Imaging System For A Laser Metal Deposition Process, Shyam Barua, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The size of the melt pool created by the laser is one of the most important quality characteristic in a laser metal deposition process. This paper discusses the development of a low-cost vision system to automatically determine the size of the melt pool for in-process control. To cope with the intense infrared signal from the laser and melt pool, external ultraviolet illumination is paired with narrow bandpass filters on a usb microscope to achieve a clear image of the melt pool. The sensitivity of the melt pool to changes in system parameters and various substrate materials are also evaluated.

Effect Of Different Graphite Materials On Electrical Conductivity And Flexural Strength Of Bipolar Plates Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Graphite is an excellent material for bipolar plates used in Proton Exchange Membrane (PEM) fuel cell due to its great chemical resistance, but the brittle nature makes it difficult to manufacture. Selective Laser Sintering (SLS) based on layer-by-layer manufacturing technology can fabricate graphite bipolar plates with complex gas flow channels. To improve the performance of bipolar plates including electrical conductivity and flexural strength, different graphite materials (natural graphite, synthetic graphite, carbon black, and carbon fiber) were investigated to fabricate test samples. These samples then went through post processing including carbonization and infiltration. The results show that bipolar plates with electrical …

Laser Based Rapid Manufacturing Of Metallic Gas Diffusion Layers For Pem Fuel Cells, Gargi Tandra, Todd E. Sparks, Shyam Barua, Nikhil P. Kulkarni, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Gas Diffusion layers (GDL’s) are an essential component of Polymer Electrolyte Membrane Fuel cells (PEMFC’s) which aid in thermal & electrical conductivities, water management and act as backup layers for the membrane electrode assemblies. This paper summarizes the effort to prototype metallic GDL designs using a miniature laser deposition system developed at Missouri University of Science & Technology. The pore sizes are controlled by masking the diverging laser beam using stainless steel masks of varying sizes and shapes. The through pore feature and further treatment of the GDL’s for hydrophobicity reduces the water management issue and thereby increases the performance …

Mea Manufacturing Using An Additive Manufacturing Process To Deposit A Catalyst Pattern In An Mea And Its Impact On Cost Reduction, Nikhil P. Kulkarni, Todd E. Sparks, Gargi Tandra, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The manufacturing of a fuel cell Membrane Electrode Assembly (MEA) is a significant cost driver in polymer-electrolyte membrane (PEM) fuel cell technologies, primarily due to the inclusion of expensive materials in the catalyst layer. The selective deposition of a catalyst on the MEA of a fuel cell can drastically reduce the costs depending upon the catalyst, method used for deposition, and production volume. In this paper, testing and analysis of a novel catalyst iridium oxide is discussed. The performance of the catalyst will be compared with the conventional catalysts which will give us an estimate of its effectiveness however, in …

Multi-Axis Planning System (Maps) For Hybrid Laser Metal Deposition Processes, Frank W. Liou, Jianzhong Ruan, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper summarizes the research and development of a Multi-Axis Planning System (MAPS) for hybrid laser metal deposition processes. The project goal is to enable the current direct metal deposition systems to fully control and utilize multi-axis capability to make complex parts. MAPS allows fully automated process planning for multi-axis layered manufacturing to control direct metal deposition machines for automated fabrication. Such a capability will lead to dramatic reductions in lead time and manufacturing costs for high-value, low-volume components with high performance material. The overall approach, slicing algorithm, machine simulation for planning validation, and the planning results will be presented.

Selective Laser Sintering And Freeze Extrusion Fabrication Of Scaffolds For Bone Repair Using 13-93 Bioactive Glass: A Comparison, Krishna C. R. Kolan, Nikhil P. Doiphode, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

13-93 glass is a third-generation bioactive material which accelerates the bone’s natural ability to heal by itself through bonding with surrounding tissues. It is an important requirement for synthetic scaffolds to maintain their bioactivity and mechanical strength with a porous internal architecture comparable to that of a human bone. Additive manufacturing technologies provide a better control over design and fabrication of porous structures than conventional methods. In this paper, we discuss and compare some of the common aspects in the scaffold fabrication using two such processes, viz. selective laser sintering (SLS) and freeze extrusion fabrication (FEF). Scaffolds fabricated using each …

A Generalized Finite Element Formulation For Arbitrary Basis Functions: From Isogeometric Analysis To Xfem, D. J. Benson, Y. Bazilevs, E. Deluycker, Ming-Chen Hsu, M. Scott, T. J. R. Hughes, T. Belytschko

Ming-Chen Hsu

Many of the formulations of current research interest, including iosogeometric methods and the extended finite element method, use nontraditional basis functions. Some, such as subdivision surfaces, may not have convenient analytical representations. The concept of an element, if appropriate at all, no longer coincides with the traditional definition. Developing a new software for each new class of basis functions is a large research burden, especially, if the problems involve large deformations, non-linear materials, and contact. The objective of this paper is to present a method that separates as much as possible the generation and evaluation of the basis functions from …

Development Of A Task Assignment Tool To Customize Job Descriptions And Close Person-Job Fit Gaps, Bryan W. Booker

Dissertations

Does the knowledge worker fit the job or should the job fit the knowledge worker? This research developed a methodology and a tool to customize a knowledge worker’s job design to better fit their knowledge, skills, abilities and characteristics. The research outcomes support the customization of the job design to improve person-job fit, the documentation of the customized job design as a position description, and the use of a structured person-task assignment process. The recommended task assignment process includes a job aid that uses multivariate equations to predict expected task performance. Data were collected from two knowledge worker sub-groups: lean …

A Stochastic Product Priority Optimization Method For Remanufacturing System Based On Genetic Algorithm, Xiong Xiong

Theses and Dissertations - UTB/UTPA

Increasing number of manufacturers are developing remanufacturing facilities to recover end-of-life products for product/component reuse and material recycling while the high uncertainty pattern of returned products complicates the production planning. In this thesis a stochastic production priority optimization method, considering various priority concerns for remanufacturing systems is developed. Priority ranking and matching algorithm is developed to determine the priority rule, using thirteen weighting factors. Queueing models are developed to formulate the objective function, a genetic algorithm is then developed to search optimal solution under different business configurations. Result of this research will provide insights to priority assignment mechanism, which in …

An Analytic Hierarchy Process Approach To Assess Health Service Quality, Yan Li

Theses and Dissertations - UTB/UTPA

While improving quality in health care is currently at the forefront of professional, political, and managerial attention, the key dimensions constituting health-care quality have not been fully understood. Also, few valid approaches have been proposed to the measurement of health-care quality. In this research, the Analytic Hierarchy Process (AHP) approach is applied to study the structure of health-care quality and deducted relative importance weights for each of the quality elements. A statistical quality model is derived to assess medical equipment quality which is an important part constituting the general health-care quality. Finally, the application of the AHP model to assess …

An Experimental Investigation Of Friction Bit Joining In Az31 Magnesium And Advanced High-Strength Automotive Sheet Steel, Rebecca Gardner

Theses and Dissertations

Friction Bit Joining (FBJ) is a recently developed spot joining technology capable of joining dissimilar metals. A consumable bit cuts through the upper layer of metal to be joined, then friction welds to the lower layer. The bit then snaps off, leaving a flange. This research focuses on FBJ using DP980 or DP590 steel as the lower layer, AZ31 magnesium alloy as the top layer, and 4140 or 4130 steel as the bit material. In order to determine optimal settings for the magnesium/steel joints, experimentation was performed using a purpose-built computer controlled welding machine, varying factors such as rotational speeds, …

Testing The Test: Validity And Reliability Of Senior Exit Exam, Lizabeth Schlemer, Daniel Waldorf

Industrial and Manufacturing Engineering

A senior exit exam is considered an excellent direct measure of student learning for ABET assessment, but the usefulness of the information gathered is related to the validity and reliability of the test itself. The Industrial and Manufacturing Engineering Department at California Polytechnic State University, San Luis Obispo has used a content exam for several years. This paper will discuss test development, administration, and the role it plays in the assessment process. In addition, the test is evaluated using the standard psychometric techniques of reliability and validity. The results of the evaluation are used to refine the test. The importance …

Natural Fibers And Fiberglass: A Technical And Economic Comparison, Justin Andrew Zsiros

Theses and Dissertations

Natural fibers have received attention in recent years because of their minimal environmental impact, reasonably good properties, and low cost. There is a wide variety of natural fibers suitable for composite applications, the most common of which is flax. Flax has advantages in tensile strength, light weight, and low cost over other natural fibers. As with other natural and synthetic fibers, flax is used to reinforce both thermoset and thermoplastic matrices. When flax is used in thermoplastic matrices, polypropylene and polyethylene are the main resins used. Although at first glance flax may seem to be a cheaper alternative to fiberglass, …

Testing Guidelines For New Product Development, Derek W. Egbert

Theses and Dissertations

While many literary sources outline the product development process, few make mention of the prototyping and testing stage. This thesis suggests that because of its importance in the product development process, "Testing" should be documented as a major step and not just listed as a side note. As part of the testing step, it is suggested that standardized, in-use, and market tests be used to properly evaluate a product. While many rely solely on standardized tests to validate their products, effective in-use tests can be another vital tool that can prove the performance of the product in more specific and …

Development And Assessment Of A Pcb Layout And Manufacturong Laboratory Module In Introductory Electric Circuits For Ee And Non-Ee Majors, Albert Liddicoat, Jianbiao Pan, James G. Harris, Gary Perks, Linda Shepherd

Industrial and Manufacturing Engineering

In standard introductory electric circuits laboratories for electrical engineering (EE) majors and non-EE majors, prototype boards are typically used to construct and test electric circuits. Students typically do not learn how to design and manufacture Printed Circuit Boards (PCB) that are commonly used in more sophisticated design projects and other engineering applications. This paper will present the development and assessment of a PCB layout and manufacturing laboratory module that has been used in introductory electric circuits laboratories for EE and non-EE majors. The feasibility of integrating the new PCB layout and manufacturing module into the electric circuit course will be …

Assessing Curriculum Improvement Through Senior Projects, Jianbiao Pan, Albert Liddicoat, James G. Harris, Linda Shepherd

Industrial and Manufacturing Engineering

Senior project and/or capstone design courses are intended to provide a culminating design experience for students and to demonstrate their understanding of engineering knowledge and their ability to apply that knowledge to practical problems. It is expected that the quality and attributes of students’ senior design projects can be used as a good measure of determining how well the curriculum prepares students to engage in engineering design as well as a measure of faculty teaching and student learning. This paper reports the results of a study designed to assess whether the new computer engineering curriculum implemented at Cal Poly over …

Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent

Aerospace Engineering

California Polytechnic State University students designed, built, and certified ground support equipment for the Northrop Grumman Massive Heat Transfer Experiment. The Cal Poly design team built the 10000, 20000, and 30000 assemblies to meet Northrop Grumman requirements. The requirements included interface limitations, design load factors, delivery, and testing specifications. The design process consists of requirements generation, conceptual design, preliminary design, design reviews, manufacturing, and certification. The hardware was successfully completed and is used at the Johnson Space and Kennedy Space Center.

Laser Clean Room Re-Design: A Manufacturing Facility Re-Layout, Jennifer J. Siu

Industrial and Manufacturing Engineering

Alcon’s Laser Clean Room fosters inefficient production practices, is outdated for its current process, and lacking in clear process/product flow. A facility re-design is applied to bring order, efficiency, and optimize flow in the laser production lines.

Deliverables include a new layout that decreases product travel distances and increases productivity as well as an implementation plan and cost/savings analysis. Major design decisions include downsizing the clean room, sorting to find waste and establishing clear process/product flows. The design was implemented within three weeks and results yield 29% reduction of product travel distance, 10.4 hrs/day saved from eliminated gowning time and …

The Applications And Limitations Of Printable Batteries, Matthew Delmanowski

Graphic Communication

This study focuses on the potential applications for printed batteries and how they could affect the printing industry. It also analyzes the main problems associated with manufacturing this technology and what needs to be done to overcome these issues. To find the answers to these questions, two methods of research were used. The first was through the elite and specialized interviewing of Dr. Scott Williams of Rochester Institute of Technology and Professor Nancy Cullins from Cal Poly. The second form of research was a common, yet useful, method called secondary research. This entailed looking at recent written research papers about …

Adaptive Cutting Force Control For Process Stability Of Micro Ultrasonic Machining, Ala'a M. Al-Okaily

Industrial and Management Systems Engineering -- Dissertations and Student Research

The growing demand for miniaturized products motivates the advancement in micromanufacturing processes research and development. Micro Ultrasonic Machining (Micro USM) is a downscaled version of a macro USM process that is developed to fabricate complex features in chemically inert, nonconductive, hard, brittle materials such as quartz, glass, and ceramics. These materials have many applications in various fields such as optics, electronics, MEMS, and biotechnology. The micro USM process stability is hard to accomplish, because it is highly influenced by the accuracy of the machining system and the variation of the process control parameters. The repeatability of micro USM machined features …