Manufacturing Commons^™

Rotary Friction Welding Versus Fusion Butt Welding Of Plastic Pipes – Feasibility And Energy Perspective, Ramsey F. Hamade, Tarek R. Andari, Ali H. Ammouri, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

According to the Plastics Pipe Institute, butt fusion is the most widely used method for joining lengths of PE pipe and pipe to PE fittings “by heat fusion” (https://plasticpipe.org/pdf/chapter09.pdf). However, butt-welding is not energy-cognizant from the point of view of a phase-change fabrication method. This is because the source of heating is external (heater plate). The initial heating and subsequent maintenance at relatively high temperature (above 200 C for welding of high-density polyethylene pipe) is energy intensive. Rotary friction welding, on the other hand focuses the energy where and when as needed because it uses electric motor to generate mechanical …

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 …

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 …

Analysis Of Surface Integrity In Machining Of Aisi 304 Stainless Steel Under Various Cooling And Cutting Conditions, F. Klocke, B. Döbbeler, S. Lung, S. Seelbach, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Recent studies have shown that machining under specific cooling and cutting conditions can be used to induce a nanocrystalline surface layer in the workspiece. This layer has beneficial properties, such as improved fatigue strength, wear resistance and tribological behavior. In machining, a promising approach for achieving grain refinement in the surface layer is the application of cryogenic cooling. The aim is to use the last step of the machining operation to induce the desired surface quality to save time-consuming and expensive post machining surface treatments. The material used in this study was AISI 304 stainless steel. This austenitic steel suffers …

Sustainable Living Factories For Next Generation Manufacturing, Yoram Koren, Xi Gu, Fazleena Badurdeen, Ibrahim S. Jawahir

Mechanical Engineering Faculty Publications

To be profitable and to generate sustainable value for all stakeholders, next generation manufacturers must develop capabilities to rapidly and economically respond to changing market needs while at the same time minimizing adverse impacts on the environment and benefiting society. 6R-based (Reduce, Reuse, Recycle, Recover, Redesign and Remanufacturing) sustainable manufacturing practices enable closed-loop and multi-life cycle material flow; they facilitate producing more sustainable products using manufacturing processes and systems that are more sustainable. Reconfigurable Manufacturing Systems (RMS) and its characteristics of scalability, convertibility, diagnosability, customization, modularity and integrability have emerged as a basis for living factories for next generation manufacturing …

Stochastic Bi-Level Optimization Models For Efficient Operating Room Planning, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Within a hospital, the operating room (OR) department has the largest cost and revenue. Because of the aging population, the demand for surgical services has been increasing sharply in recent years. At the other hand, the rate of OR capacity expansion is lower than the rate of increasing demand. As a result, OR managers must leverage their resources by efficient OR planning. OR planning is challenging because of multiple competing\conflicting objectives such cost minimization and throughput maximization. Inherent uncertainty in the surgical procedures and patients arrivals complicate the decision making process. This increases the risk of non-realization of the system …

Towards Developing Sustainable Reconfigurable Manufacturing Systems, Aihua Huang, Fazleena Badurdeen, Ibrahim S. Jawahir

Mechanical Engineering Faculty Publications

This paper aims to examine the sustainable manufacturing performance of Reconfigurable Manufacturing Systems (RMSs) using existing sustainable manufacturing metrics. RMS has six key characteristics including modularity, integrability, customization, scalability, convertibility, and diagnosability. In this paper, ‘convertibility’ is quantified by considering configuration convertibility, machine convertibility, and material handling device convertibility from the RMS perspective. In addition, the performance of RMSs with different convertibility levels is also evaluated by using sustainable manufacturing metrics. A numerical example is used to demonstrate the computational approach. Results of the analysis are used to show how sustainable manufacturing performance of RMS changes as system convertibility varies. …

Regression Analysis Of Factors Impacting Problem Solving Engagement Within Lean Systems Implementation, David M. Parsley Ii

Theses and Dissertations--Mechanical Engineering

Organizations around the world have attempted to implement the concepts of the Toyota Production System (TPS), commonly referred to as Lean, with limited sustainable success. The central principles of TPS, continuous improvement and respect for people, are grounded in the Japanese values of Monozukuri and Hitozukuri. Monozukuri deals with creating or making a product, while Hitozukuri conveys the idea of developing people through learning. In order for organizations to adopt these values they must have a system that engages employees at all levels in applying problem solving to improve their work. This research uses organizational assessments obtained from a variety …

The Kentucky Re-Entry Universal Payload System (Krups): Sub-Orbital Flights, James Devin Sparks

Theses and Dissertations--Mechanical Engineering

The Kentucky Re-entry Universal Payload System (KRUPS) is an adaptable testbed for atmosphere entry science experiments, with an initial application to thermal protection systems (TPS). Because of the uniqueness of atmospheric entry conditions that ground testing is unable to replicate, scientists principally rely on numerical models for predicting entry conditions. The KRUPS spacecraft, developed at the University of Kentucky, provides an inexpensive means of obtaining validation data to verify and improve these models.

To increase the technology readiness level (TRL) of the spacecraft, two sub-orbital missions were developed. The first mission, KUDOS, launched August 13th, 2017 on a Terrier-Improved Malamute …

Bayesian-Integrated System Dynamics Modelling For Production Line Risk Assessment, Sudhir Punyamurthula

Theses and Dissertations--Mechanical Engineering

Companies, across the globe are concerned with risks that impair their ability to produce quality products at a low cost and deliver them to customers on time. Risk assessment, comprising of both external and internal elements, prepares companies to identify and manage the risks affecting them. Although both external/supply chain and internal/production line risk assessments are necessary, internal risk assessment is often ignored. Internal risk assessment helps companies recognize vulnerable sections of production operations and provide opportunities for risk mitigation.

In this research, a novel production line risk assessment methodology is proposed. Traditional simulation techniques fail to capture the complex …

Note On The Rate And Energy Efficiency Limits For Additive Manufacturing, Timothy Gutowski, Sheng Jiang, Daniel Cooper, Gero Corman, Michael Hausmann, Jan-Anders Manson, Timo Schudeleit, Konrad Wegener, Matias Sabelle, Jorge Ramos-Grez, Dusan P. Sekulic

Mechanical Engineering Faculty Publications

We review the process rates and energy intensities of various additive processing technologies and focus on recent progress in improving these metrics for laser powder bed fusion processing of metals, and filament and pellet extrusion processing of polymers and composites. Over the last decade, observed progress in raw build rates has been quite substantial, with laser metal processes improving by about 1 order of magnitude, and polymer extrusion processes by more than 2 orders of magnitude. We develop simple heat transfer models that explain these improvements, point to other possible strategies for improvement, and highlight rate limits. We observe a …

Pulsed Laser Beam Welding Of Pd43Cu27Ni10P20 Bulk Metallic Glass, Ling Shao, Amit Datye, Jiankang Huang, Jittisa Ketkaew, Sung Woo Sohn, Shaofan Zhao, Sujun Wu, Yuming Zhang, Udo D. Schwarz, Jan Schroers

Electrical and Computer Engineering Faculty Publications

We used pulsed laser beam welding method to join Pd₄₃Cu₂₇Ni₁₀P₂₀ (at.%) bulk metallic glass and characterized the properties of the joint. Fusion zone and heat-affected zone in the weld joint can be maintained completely amorphous as confirmed by X-ray diffraction and differential scanning calorimetry. No visible defects were observed in the weld joint. Nanoindentation and bend tests were carried out to determine the mechanical properties of the weld joint. Fusion zone and heat-affected zone exhibit very similar elastic moduli and hardness when compared to the base material, and the weld joint shows high …

Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li

Mechanical Engineering Faculty Publications

The operating room (OR) is responsible for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we observe an ironic parallel increase among expenditure and waiting time. Therefore, improving OR scheduling has become obligatory, particularly in terms of patient flow and benefit. Most of the hospitals rely on average patient arrivals and processing times in OR planning. But in practice, variations in arrivals and processing times causes high instability in OR performance. Our model of optimization provides OR schedules maximizing patient flow and benefit at a fixed level of …

An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …

Sustainable Manufacturing Performance Evaluation: Integrating Product And Process Metrics For Systems Level Assessment, Aihua Huang, Fazleena Badurdeen

Mechanical Engineering Faculty Publications

This paper builds on the previously developed product sustainability index (ProdSI) and process sustainability index (ProcSI), and presents a framework for sustainable manufacturing performance evaluation at the systems level. The framework is then used to propose a comprehensive set of metrics for the enterprise level following a five-stage metrics hierarchy (individual metrics, sub-clusters, clusters, sub-index and index). The 6R concept (reduce, reuse, recycle, recover, redesign and remanufacture), total life-cycle emphasis, and triple bottom line (TBL) are considered for selecting relevant metrics. Finally, the metrics are integrated to develop an index for enterprise level sustainability assessment and …

Strategies For Value Creation Through Sustainable Manufacturing, Fazleena Badurdeen, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Making the business case and establishing strategic directions for sustainable manufacturing requires a collaborative effort. Strategic capabilities that can help create sustainable value for all stakeholders must be identified. Technologies and methodologies to provide these capabilities for implementation must then be developed, through public-private partnerships. This paper presents major business imperatives and strategic capabilities necessary to enable value creation through sustainable manufacturing identified based on extensive engagement with business leaders and industry professionals as well as academic experts and government agency representatives. The paper also presents a future vision for sustainable products, processes and systems that can be derived from …

Investigation Of Polishing Methods And Surface Analysis After Machining Aisi 4140 Alloy Steel, Qiang Qi

Theses and Dissertations--Mechanical Engineering

AISI 4140 alloy steel has been a very common material to be investigated in automotive and aerospace industries for several decades. AISI 4140 alloy steel is chromium, molybdenum, and manganese containing low alloy steel. It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength. The functional performance is largely determined by the surface states after machining.

The aim of the present study is to explore the polishing methods and surface analysis after machining AISI 4140 alloy steel in different cutting speeds and cooling conditions. The surface analysis includes surface roughness, hardness and residual stresses. Compared to traditional …

Adaptive Scheduling For Operating Room Management, Honghan Ye

Theses and Dissertations--Mechanical Engineering

The perioperative process in hospitals can be modelled as a 3-stage no-wait flow shop. The utilization of OR units and the average waiting time of patients are related to makespan and total completion time, respectively. However, minimizations of makespan and total completion time are NP-hard and NP-complete. Consequently, achieving good effectiveness and efficiency is a challenge in no-wait flow shop scheduling. The average idle time (AIT) and current and future idle time (CFI) heuristics are proposed to minimize makespan and total completion time, respectively. To improve effectiveness, current idle times and future idle times are taken into consideration …

Torque Response Of Thin-Film Ferromagnetic Prisms In Uniform Magnetic Fields At Macro And Micro Scales, Soroosh Torabi

Theses and Dissertations--Mechanical Engineering

The non-contact nature of magnetic actuation makes it useful in a variety of microscale applications, from microfluidics and lab-on-a-chip devices to classical MEMS or even microrobotics. Ferromagnetic materials like nickel are particularly attractive, because they can be easily deposited and patterned using traditional lithography-based microscale fabrication methods. However, the response of ferromagnetic materials in a magnetic field can be difficult to predict. When placed in a magnetic field, high magnetization is induced in these ferromagnetic materials, which in turn generates force and/or torque on the ferromagnetic bodies. The magnitude and direction of these forces are highly dependent on the type …

The Limits & Effects Of Draw On Properties And Morphology Of Pan-Based Precursor And The Resultant Carbon Fibers, Sarah Edrington

Theses and Dissertations--Mechanical Engineering

The process, structure, and property relationship of PAN fiber as a precursor to carbon fiber was studied. The limitations of stable spinning and property improvement associated with hot draw in solution spinning were found and quantified. Conditions were varied to generated precursor fiber up to the limit of draw, from which actual samples were collected for thermal conversion to carbon fiber. Samples of PAN and subsequent carbon fiber were characterized using tensile testing and x-ray analysis. The effects of draw on modulus and break stress, as well as the orientation of the crystalline structure of both parent precursor and resultant …

Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, Soheil Saedi

Theses and Dissertations--Mechanical Engineering

Selective Laser Melting (SLM) of Additive Manufacturing is an attractive fabrication method that employs CAD data to selectively melt the metal powder layer by layer via a laser beam and produce a 3D part. This method not only opens a new window in overcoming traditional NiTi fabrication problems but also for producing porous or complex shaped structures. The combination of SLM fabrication advantages with the unique properties of NiTi alloys, such as shape memory effect, superelasticity, high ductility, work output, corrosion, biocompatibility, etc. makes SLM NiTi alloys extremely promising for numerous applications.

The SLM process parameters such as laser power, …

A Framework And Metrics For Sustainable Manufacturing Performance Evaluation At The Production Line, Plant And Enterprise Levels, Aihua Huang

Theses and Dissertations--Mechanical Engineering

Sustainable manufacturing is becoming increasingly important due to scarcity of natural resources, stricter regulations and increasing customer demand for sustainable products. Sustainable manufacturing involves the use of sustainable processes and systems to produce more sustainable products. In order to meet these demands for sustainable products, manufacturing companies have to adopt numerous strategies to achieve sustainable manufacturing. The approach for evaluating sustainable products and processes have been investigated in previous work where product/process sustainability indices were proposed. However, no comprehensive methods are available for sustainable manufacturing performance evaluation at the system level. This work aims to develop two alternate methods for …

Development Of A Supplier Segmentation Method For Increased Resilience And Robustness: A Study Using Agent Based Modeling And Simulation, Adam J. Brown

Theses and Dissertations--Mechanical Engineering

Supply chain management is a complex process requiring the coordination of numerous decisions in the attempt to balance often-conflicting objectives such as quality, cost, and on-time delivery. To meet these and other objectives, a focal company must develop organized systems for establishing and managing its supplier relationships. A reliable, decision-support tool is needed for selecting the best procurement strategy for each supplier, given knowledge of the existing sourcing environment. Supplier segmentation is a well-established and resource-efficient tool used to identify procurement strategies for groups of suppliers with similar characteristics. However, the existing methods of segmentation generally select strategies that optimize …

Product Disassemblability And Remanufacturability Assessment: A Quantitative Approach, Ammar Ali

Theses and Dissertations--Mechanical Engineering

Majority of the products get discarded at end-of-life (EoL), causing environmental pollution, and resulting in a complete loss of all materials and embodied energy. Adopting a closed-loop material flow approach can aid preventing such losses and enable EoL value recovery from these products. Design and engineering decisions made and how products are used impact the capability to implement EOL strategies such as disassembly and remanufacturing. Some underlying factors affecting the capability to implement these EOL strategies have been discussed in previous studies. However, relevant metrics and attributes are not well defined and comprehensive methods to quantitatively evaluate them are lacking. …

Evolution Of The Automotive Body Coating Process—A Review, Nelson K. Akafuah, Sadegh Poozesh, Ahmad Salaimeh, Gabriela Patrick, Kevin Lawler, Kozo Saito

Mechanical Engineering Faculty Publications

Automotive coatings and the processes used to coat automobile surfaces exemplify the avant-garde of technologies that are capable of producing durable surfaces, exceeding customers’ expectations of appearance, maximizing efficiency, and meeting environmental regulations. These accomplishments are rooted in 100 years of experience, trial-and-error approaches, technique and technology advancements, and theoretical assessments. Because of advancements directed at understanding the how, why, when, and where of automobile coatings, the progress in controlling droplets and their deposition attributes, and the development of new technologies and paint chemistries, a comprehensive and up-to-date review of automobile coatings and coating technologies was considered to be of …

Cryogenic Processing Of Al 7050-T7451 Alloy For Improved Surface Integrity, Bo Huang

Theses and Dissertations--Mechanical Engineering

Al 7050-T7451 alloy with good combinations of strength, stress corrosion cracking resistance and toughness, is used broadly in the aerospace/aviation industry for fatigue-critical airframe structural components. However, it is also considered as a highly anisotropic alloy as the crack growth behavior along the short transverse direction is very different from the one in the long transverse direction, due to the inhomogeneous microstructure with the elongated grains distributed in the work material used in the sheet/plate applications. Further processes on these materials are needed to improve its mechanical and material properties and broaden its applications.

The material with ultra-fine or nano …

Energy Resources Use Metrics, Rahul Y. Nehete

Theses and Dissertations--Mechanical Engineering

Energy resources use has been considered as a key component of sustainable development. Data related to global, regional, state, sector, industry and process demonstrate that a significant reduction of energy resources for a given production rate in manufacturing processes requires an introduction of transformational technologies at the process level, propagating the impact to higher scales, leading not just to a gradual improvement of traditional technologies but to more sustainable development.

The study offers two approaches to the formulation of the limits of energy use in the context of sustainable development. The first is to construct a map of key selected …

Effect Of Heating And Ionization Of Four Atomizing Gases On The Spray Characteristics Of A High Volume Low Pressure Spray Atomizer, Anthony V. Adornato

Theses and Dissertations--Mechanical Engineering

The disintegration of a liquid jet emerging from a nozzle by a high speed gas stream has been under investigation of several decades. A result of the liquid jet disintegration is droplet formation. This process is referred to as atomization. Industrial applications use atomization as a method for applying coatings to substrates. It has been reported that the use of other atomizing gases instead of compressed plant air will positively affect paint droplet size distributions, spray patterns and finish qualities; furthermore, the ionization and heating of the atomizing gas was reported to positively affect finish qualities. Although ionization techniques have …

A Framework For Sustainable Material Selection For Multi-Generational Components, Ryan T. Bradley

Theses and Dissertations--Mechanical Engineering

The early stages of a product’s design are a critical time for decisions that impact the entire life-cycle cost. Product designers have mastered the first generation; however, they currently do not have the ability to know the impact of their decisions on the multi-generational view. This thesis aims at closing the gap between total life-cycle information and the traditional design process in order to harbor sustainable value creation among all stakeholders involved. A framework is presented that uses a combination of a life-cycle costing methodology and an evolutionary algorithm in order to achieve a sustainability assessment for a true multi-generational …

Engineered Surface Properties Of Porous Tungsten From Cryogenic Machining, Julius M. Schoop

Theses and Dissertations--Chemical and Materials Engineering

Porous tungsten is used to manufacture dispenser cathodes due to it refractory properties. Surface porosity is critical to functional performance of dispenser cathodes because it allows for an impregnated ceramic compound to migrate to the emitting surface, lowering its work function. Likewise, surface roughness is important because it is necessary to ensure uniform wetting of the molten impregnate during high temperature service. Current industry practice to achieve surface roughness and surface porosity requirements involves the use of a plastic infiltrant during machining. After machining, the infiltrant is baked and the cathode pellet is impregnated. In this context, cryogenic machining is …