Manufacturing Commons^™

Use Of Swir Imaging To Monitor Layer-To-Layer Part Quality During Slm Of 304l Stainless Steel, Cody S. Lough, Xin Wang, Christopher C. Smith, Olaseni Adeniji, Robert G. Landers, Douglas A. Bristow, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper evaluates using in-situ SWIR imaging to monitor part quality and identify potential defect locations introduced during Selective Laser Melting (SLM) of 304L stainless steel. The microstructure (porosity, grain size, and phase field) and engineering properties (density, modulus, and yield strength) depend on the thermal history during SLM manufacturing. Tensile test specimens have been built with a Renishaw AM250 using varied processing conditions to generate different thermal histories. SWIR imaging data is processed layer-to-layer to extract features in the thermal history for each process condition. The features in the thermal history are correlated with resulting part engineering properties, microstructure, …

Experimental Characterization Of A Direct Metal Deposited Cobalt-Based Alloy On Tool Steel For Component Repair, Xinchang Zhang, Tan Pan, Wei Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Die casting dies made of tool steel is subject to impact, abrasion and cyclic thermomechanical loading that delivers damage such as wear, corrosion, and cracking. To repair such defects, materials enveloping the damage need to be machined and refilled. In this study, V-shape defects with varied sidewall inclination angles were prepared on H13 tool steel substrates and refilled with cobalt-based alloy using direct metal deposition (DMD) for superior hardness and wear resistance. The microstructure of rebuild samples was characterized using an optical microscope (OM) and scanning electron microscope (SEM). Elemental distribution from the substrate to deposits was analyzed using energy …

The Influence Of Build Parameters On The Compressive Properties Of Selective Laser Melted 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, R. Hussein, S. Anandan, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, H. Misak, M. A. Walker

Materials Science and Engineering Faculty Research & Creative Works

Process parameters used during Selective Laser Melting (SLM) process have significant effects on the mechanical properties of the manufactured parts. In this study, the influence of two build parameters (build orientation and hatch angle) on the compressive properties of 304L stainless steel was evaluated. SLM 304L samples were manufactured using three hatch angles, 0°, 67°,105° and two orientations, z-direction and x-direction, and tested using a compression frame according to ASTM E9-09. Bulk density was measured according to ASTM C373-17 before compression. Properties evaluated were the bulk density, yield strength, strength at 15% plastic-strain and strength at 30% plastic-strain. Results showed …

Fiber-Fed Printing Of Free-Form Free-Standing Glass Structures, John M. Hostetler, Jason E. Johnson, Jonathan T. Goldstein, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Materials Science and Engineering Faculty Research & Creative Works

Additive Manufacturing (AM) of low-profile 2.5D glass structures has been demonstrated using a fiber-fed laser-heated process. In this process, glass fibers with diameters 90-125 μm are supported as they are fed into the intersection of the workpiece and a CO₂ laser beam. The workpiece is positioned by a four-axis CNC stage with coordinated rotational/transitional kinematics. The laser energy at λ = 10.6 μm is coupled to phonon modes in the glass, locally heating it above its working point. The rapid heating and cooling process allows for the deposition of various glasses into free-standing three-dimensional structures such as trusses and …

Effects Of Identical Parts On A Common Build Plate On The Modal Analysis Of Slm Created Metal, Tristan Cullom, Troy Hartwig, Ben Brown, Kevin Johnson, Jason Blough, Andrew Barnard, Robert G. Landers, Douglas A. Bristow, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The frequency response of parts created with Additive Manufacturing (AM) is a function of not only process parameters, powder quality, but also the geometry of the part. Modal analysis has the potential to evaluate parts by measuring the frequency response which are a function of the material response as well as the geometry. A Frequency Response Function (FRF) serves as a fingerprint of the part which can be validated against the FRF of a destructively tested part. A practical scenario encountered in Selective Laser Melting (SLM) involves multiple parts on a common build plate. Coupling between parts influences the FRF …

Characterization Of Impact Toughness Of 304l Stainless Steel Fabricated Through Laser Powder Bed Fusion Process, Sreekar Karnati, Atoosa Khiabhani, Aaron Flood, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this research, the impact toughness of powder bed based additively manufactured 304L stainless steel was investigated. Charpy specimens were built in vertical, horizontal and inclined (45⁰) orientations to investigate the variation in toughness with build direction. These specimens were tested in as-built and machined conditions. A significant difference in toughness was observed with varying build directions. The lowest toughness values were recorded when the notch was oriented in line with the interlayer boundary. The highest toughness was recorded when the notch was perpendicular to the interlayer boundary. A significant scatter in toughness values was also observed. The variation and …

An Efficient Constructive Heuristic To Balance Trade-Offs Between Makespan And Flowtime In Permutation Flow Shop Scheduling, Feidi Dang, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Balancing trade-offs between production cost and holding cost is critical for production and operations management. Utilization of a production line affects production cost, which relates to makespan, and work-in-process (WIP) inventories in a production line affect holding cost, which relate to flowtime. There are trade-offs between two objectives, to minimize makespan and to minimize flowtime. Without addressing trade-off balancing issues in flow shop scheduling, WIP inventories are still high in manufacturing, generating unnecessary holding cost. However, utilization is coupled with WIP inventories. Low WIP inventory levels might lower utilization and generate high production cost. Most existing constructive heuristics focus only …

Assessing Production Line Risk Using Bayesian Belief Networks And System Dynamics, Sudhir Punyamurthula, Fazleena Badurdeen

Mechanical Engineering Faculty Publications

Increased complexity in product design, strict regulations and a changing market make risk assessment critical for successful operations. Failure in responding quickly to raw material shortages, downtimes, deteriorating equipment conditions or other operational issues can prove to be an expensive affair. A company-wide risk assessment includes both external and internal operations. However, external/supplier risk assessment has been of major interest. Even though the scope of risk assessment at the production line level is not as broad as it is at the supply chain level, assessing risk would help recognize vulnerable areas of the production line, which would in turn help …

Microstructure And Mechanical Properties Of Selective Laser Melted Superalloy Inconel 625., Md Ashabul Anam

Electronic Theses and Dissertations

Selective Laser Melting (SLM), a powder based Additive Manufacturing (AM) process, has gained considerable attention in the aerospace, biomedical and automotive industries due to its many potential benefits, such as, capability of fabricating complex three-dimensional components, shortened design to product time, reduction in process steps, component mass reduction and material flexibility. This process uses metallic powder and is capable of fabricating complex structures with excellent microstructure which make SLM not only an improvement over other manufacturing processes but also innovative material processing technology. Inconel 625, a nickel-based super alloy is widely popular in aerospace, chemical and nuclear industries. This alloy …

Modeling And Validations Of Control Parameters For Material Extrusion-Based Additive Manufacturing Of Thixotropic Aluminum Alloys., Lars Herhold

Electronic Theses and Dissertations

Additive Manufacturing (AM) with metals has been accomplished mainly through powder bed fusion processes. Initial experiments and simulations using Material Extrusion Additive Manufacturing (MEAM) have been performed by various researchers especially using low melting alloys. Recently Stratasys Inc. submitted a patent application for the use of their Material Extrusion technology also called Fused Deposition Modeling (FDM) where they describe the process using thixotropic semi-solid alloys. Currently this process using semi-solid, engineering type alloys such as A356 or THIXALLOY 540 aluminum have not been researched to evaluate the control parameters. This research combines the in-depth knowledge of applying thixotropic semi-solid aluminum …

Experimental And Theoretical Investigation Of Mechanical Response Of Laser-Sintered Diamond Lattice Structures, Clayton Neff, Neil Hopkinson, Nathan B. Crane

Faculty Publications

Typically additive manufacturing (AM) processes are limited to a single material per part while many products benefit from the integration of multiple materials with varied properties. To achieve the benefits of multiple materials, the geometric freedom of AM could be used to build internal structures that emulate a range of different material properties such as stiffness, Poisson’s ratio, and elastic limit using only one build material. This paper examines the range of properties that can be simulated using diamond lattice structures manufactured from Nylon 12 with a commercial laser sintering process. Diamond lattices were fabricated with a unit cell length …

Impact Of Extended Sintering Times On Mechanical Properties In Pa-12 Parts Produced By Powderbed Fusion Processes, Garrett Craft, Justin Nussbaum, Nathan B. Crane, J. P. Harmon

Faculty Publications

Additive Manufacturing provides many advantages in reduced lead times and increased geometric freedom compared to traditional manufacturing methods, but material properties are often reduced. This paper considers powder bed fusion of polyamide 12 (PA12, Nylon 12) produced by three different processes: laser sintering (LS), multijet fusion (MJF)/high speed sintering (HSS), and large area projection sintering (LAPS). While all utilize similar PA12 materials, they are found to differ significantly in mechanical properties especially in elongation to break. The slower heating methods (MJF/HSS and LAPS) produce large elongation at break with the LAPS process showing 10x elongation and MJF/HSS exhibiting 2.5x the …

Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing …

Design Of Lattice Structures With Graded Density Fabricated By Additive Manufacturing, Wenjin Tao, Yong Liu, Austin T. Sutton, Krishna C. R. Kolan, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice structures fabricated by Additive Manufacturing (AM) processes are promising for many applications, such as lightweight structures and energy absorbers. However, predicting and controlling of their mechanical behaviors is challenging due to the complexity of modeling and the uncertainties exist in the manufacturing process. In this paper, we explore the possibilities enabled by controlling the local densities. A set of lattice structures with different density gradients are designed using an implicit isosurface equation, and they are manufactured by Selective Laser Melting (SLM) process with 304L stainless steel. Finite element analysis and compression test are used to evaluate their mechanical properties. …

4-D Printing Of Pressure Sensors And Energy Harvesting Devices For Engineering Education, Tzu-Liang Bill Tseng, Aditya Akundi, Hoejin Kim

Manufacturing & Industrial Engineering Faculty Publications

This paper elaborates on the development of laboratory project modules in the Industrial manufacturing and systems engineering department at The University of Texas El Paso based on Four-Dimensional (4D) printing technology. These modules are aimed at introducing the students to interdisciplinary manufacturing and emerging dimensions in manufacturing technology. 4D printing is a new dimension in additive manufacturing wherein, the 3D printed structures react to the change of parameters within the environment such as temperature, and humidity, resulting in shape change or in functionality such as electricity output, and self-healing. Recently 4D printing of simple devices for pressure sensors application were …

Fixing Vertebral Compression Fractures With Medtronic, Kelly Fitzgerald, Trevor Bingham, Alex Denbaugh, Jordan Tang, Jon Stearns

Industrial and Manufacturing Engineering

No abstract provided.

Connected Alerts Across Manufacturing Facilities, Jordan J. Moy

Industrial and Manufacturing Engineering

The lack of communication during a large project can result in costly delays when striving to achieve previously defined benchmarks. Often times, each part of a project will require verification from an employee of a specified area of expertise before being allowed to advance to the next stage. Finding these individuals can be extremely hard due to the large, spread out campus of manufacturing facilities as well as the numerous projects the company is concurrently working on. These floor support requests can sometimes take from an hour to even a whole work day, causing major delays in the production schedule. …

Process Improvement At "The Manse On Marsh", Kevin C. Manko

Industrial and Manufacturing Engineering

The Manse on Marsh is an independent and assisted living facility that prides itself on providing life-enriching care for the elderly. Considering that the staff is essential to supply this care and turnover rates are a constant factor, the company would like to reduce the time it takes to hire new employees by at least one week. To facilitate this goal, process flow maps are utilized to assess the current state of the hiring process and metrics are applied to support future state design decisions. After performing a value added analysis and identifying areas of waste, a total of 20 …

High Bay Capacity Utilization Tool, Dante C. Mazzanti, Skyler L. Schilke, Conner P. Lawston

Industrial and Manufacturing Engineering

Northrop Grumman’s Space Park facility has many inefficiencies in their high bay scheduling processes. Additionally, it is very hard for project managers to figure out the capabilities of each high bay in order to schedule their specific project. The purpose of this project is to develop a tool that can be used across the facility to easily create projects, assign projects, view room capabilities, and view a master schedule of the rooms. After researching commercially available tools, our approach to designing this system was to use tools that are already utilized at the facility (Microsoft Suite and Tableau) and engineer …

Design And Testing Of A Hands-Free Toilet Seat Opener/Closer, Jordan Benjamin Schaeffer

Industrial and Manufacturing Engineering

People tend to get frustrated when the toilet seat must be moved up or down before use. Men and women often leave the toilet seat in different positions when finished which can cause problems when men and women use the same bathroom. With gender neutral bathrooms gaining in popularity, this frustration will only increase. The objective of this project was to design and test a hands-free system to allow a user to quickly and easily open or close a toilet seat. For the product to be viable, it will have to be durable and easy to clean around, while also …

Reducing Overall Overtime Hours Accumulated By San Luis Sourdough, Marie Scholl, Emily Vallejos, Randall Yonce

Industrial and Manufacturing Engineering

The packaging department of San Luis Sourdough Company was redesigned to increase bread throughput and decrease overtime hours issued to employees. Time studies were performed to get an accurate representation of the average throughput of bread with the current packaging conveyor system. After collecting data and surveying the employees and management, we came up with three design solutions to improve their current packaging system. The first design recommendation has a low-investment and is quick to implement as it pertains to changing the worker’s schedule to alleviate the employees from working long hour shifts while increasing the bread throughput. The second …

Vial Of Life Redesign, Andrew Scott Heim, Marisonn Manalo

Industrial and Manufacturing Engineering

Cambria Anonymous Neighbors (CAN), a nonprofit organization assisting the residences of Cambria, hopes to standardize first responder procedures and make medical information easily accessible in case of a medical emergency. Currently the container costs $3.78. CAN would like to provide 2000 containers at a lower cost. After researching materials, acrylic was found to be the best option for the container material due to its low cost and durability. A laser cutter was used to cut the acrylic pieces, and then a set of step by step instructions were created to assemble the product. To reduce the cost of acrylic, the …

The Pad Route Setting Process Design, Katherine M. Peterson, Dylan C. Breitenbucher

Industrial and Manufacturing Engineering

This study took place at The Pad Climbing, a rock climbing gym in San Luis Obispo. The problem was that the process of setting new climbing routes was time - consuming and potentially dangerous. This resulted in lower capacity, high labor costs, decreased customer satisfaction, and safety risk for employees and customers. The objective of this study was to analyze the route setting process and identify areas of waste and danger, then to redesign the process to improve these areas. Techniques such as time studies, Pareto charts, and process flow mapping were used to analyze the existing process. A new …

Atlas Copco Mafi-Trench Co. Inventory Management, Logan E. Barr, Sean P. Mcgaffigan

Industrial and Manufacturing Engineering

This Senior Project Report includes three areas of focus pertaining to the inventory management practices of Atlas Copco Mafi-Trench Company (ACMTC) - cycle counting, ergonomics, and material purchasing. Various literature reviews as well as an analysis of the current state led to the project objectives. First, reduce time spent on the non-value added process of cycle counting. Second, eliminate the ergonomic hazard presented by the heavy inventory bins. Lastly, diminish the totals costs associated with inventory (ordering + carrying). The project objectives spurred numerous alternatives and a few specific deliverables. The creation of a ‘Small Parts Cycle Count’ Excel file …

Facilities Redesign Of Stockroom At Elcon Precision, David M. Brawner, Tyler O. Mastromattei, Jay Y. Matsumoto

Industrial and Manufacturing Engineering

Elcon Precision is a company based out of San Jose, California specializing in the photochemical processing of materials and brazing of metals and ceramics for a variety of different industries. Three students from the Industrial Engineering Department at California Polytechnic State University, San Luis Obispo were contacted by Elcon Precision to help redesign their stockroom and inventory areas in their San Jose location in order to allow for the future growth of the company. Elcon asked the Cal Poly project team to help increase efficiencies throughout the stockroom by creating an alternative layout that best suited the company's needs. This …

Database Implementation For Fines Management Of Student Organization, Parker K. Nomura

Industrial and Manufacturing Engineering

The Delta Upsilon fraternity at California Polytechnic State University in San Luis Obispo, California, currently has no formal system for fines management. This facilitated over $9000 in uncollected dues and fines during the 2016-17 academic year. The executive board have difficult access to accurate financial information and general members have difficult access to personal fines information. This project aims to design, implement, and test a fines management system to reduce the annual amount of unpaid dues by $4500. The system is to be cost-effective, which will be measured as a decrease in uncollected dues. The system will be beneficial to …

The Design Of A Digital Scheduling Solution For Healing Alternatives, Hailey A. Malin, Krista L. Mcallester, Anne E. Shields

Industrial and Manufacturing Engineering

The focus of this senior project is to assist Healing Alternatives, an acupuncture clinic located in San Luis Obispo, in developing a business management software to fit their needs and boost their overall organization. The approach to finding the right fit for this business included assessing their current system while simultaneously investigating other providers. Once alternatives were found that met all of Healing Alternatives’ initial requirements, trial demos were generated in order to perform user experience testing. The presented final solution, a scheduling software called Acuity Scheduling, was implemented in a three-phase move plan that occurred over the period of …

Development Of An Additive Manufacturing Compression Molding Process For Low Cost In-House Prototyping, Grant Forrester Warden

Industrial and Manufacturing Engineering

Composite parts can be manufactured using various processes. Generally, a mix of resin and fiber is formed into the desired geometry using a mold and pressure. One process used by Dr. Joseph Mello in his research is known as compression molding. Compression molds are generally made from large billets of aluminum or stainless steel, are machined by a CNC mill, and are then hand-finished with polishes and mold preparation products. This process is expensive, requires large machinery and experienced operators, and introduces long lead times relative to the design cycle of the part being manufactured. The nature of Dr. Mello's …

Julian's Forecasting, Krista R. Bowdle

Industrial and Manufacturing Engineering

This report focuses on developing a solution to a current problem faced at Julian’s Cafe and Bistro. The problem is that inaccurate order quantities are leading to inventory shortage and surplus which is causing unnecessary profit loss. After accessing and analyzing historical sales data, several forecasts were created using various approaches. After assessing each method and applying a mean absolute percentage error to see how accurate the forecasts were, the seasonal forecast with removing outliers initially was the selected method. After, this method was used to forecast the top three selling items at Julian’s and make demand predictions for busy …

Healing Alternatives Workspace Remodel, Lissandra Ilcyn, Jenifer Astrid Colmenares, Grace E. Kuffner

Industrial and Manufacturing Engineering

Healing Alternatives is an acupuncture office space located in a repurposed house in San Luis Obispo. Healing Alternatives’ current facility layout does not allow for an additional treatment room or the space to provide additional services because of the wasted space within the facility. Furthermore, patients can be disrupted by noise outside the treatment room causing a negative customer experience. The project team’s objectives are to:

o Design two layout alternatives

o Provide a time estimate for each alternative

o Provide a cost analysis of each alternative

o Implement 5s methodology on the storage room

o Provide a 2D-3D model …