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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Friction Bit Joining of Similar Alloy Sheets of High-Strength Aluminum Alloy 7085

Okazaki, Matthew R 01 June 2018 (has links)
Friction Bit Joining (FBJ) is a new technology used primarily in joining dissimilar metals. Its primary use has been focused in the automotive industry to provide an alternative joining process to welding. As automotive manufacturing has continually pushed toward using dissimilar materials, new joining processes have been needed to replace traditional welding practices that do not perform well when materials are not weld compatible. FBJ meets these needs perfectly as it provides strength as well as the ability to join materials of almost any kind.The purpose of this research was to explore different applications of the FBJ process. Traditionally FBJ has used a steel bit to drill through a thin piece of aluminum and weld to a piece of steel behind the aluminum. This research explored a different application of FBJ by using a steel bit to drill through multiple pieces of aluminum and weld to a small steel bit on the backside of the aluminum. The primary goal of this research was to answer two questions. (1) How does drilling impact peak weld strength and (2) Does an optimal shank diameter exist in terms of peak weld strength? As in other research, no universal parameters were found for optimization of lap shear, cross tension and t-peel tests. Drilling was found to be an important factor in peak weld strength. Number of flutes on the consumable steel bit was varied to see the impact of better and worse chip clearance ability. Increasing number of flutes was found to positively impact peak weld strength to a point. Optimal number of flutes was found to be different for each type of testing. It was found that there was an optimal bit head to bit shank diameter ratio that optimized peak weld strength. Again the optimal diameter was different for each test. Bits of different diameters were created and then tested to measure the impact of varying shank diameters on peak weld strength. It was found that there was a strength tradeoff between two localized joint areas in diameter testing. Decreasing the shank diameter increased the amount of overlap formed by the bit head over the top coupon. This shifted strength to the bit head region. While this strengthened the bit head region of the joint, strength was sacrificed in the bit-nut intersection. This tradeoff was consistently found in all test types.
2

Friction Bit Joining of Similar Alloy Sheets of High-Strength Aluminum Alloy 7085

Okazaki, Matthew R 01 June 2018 (has links)
Friction Bit Joining (FBJ) is a new technology used primarily in joining dissimilar metals. Its primary use has been focused in the automotive industry to provide an alternative joining process to welding. As automotive manufacturing has continually pushed toward using dissimilar materials, new joining processes have been needed to replace traditional welding practices that do not perform well when materials are not weld compatible. FBJ meets these needs perfectly as it provides strength as well as the ability to join materials of almost any kind.The purpose of this research was to explore different applications of the FBJ process. Traditionally FBJ has used a steel bit to drill through a thin piece of aluminum and weld to a piece of steel behind the aluminum. This research explored a different application of FBJ by using a steel bit to drill through multiple pieces of aluminum and weld to a small steel bit on the backside of the aluminum. The primary goal of this research was to answer two questions. (1) How does drilling impact peak weld strength and (2) Does an optimal shank diameter exist in terms of peak weld strength? As in other research, no universal parameters were found for optimization of lap shear, cross tension and t-peel tests. Drilling was found to be an important factor in peak weld strength. Number of flutes on the consumable steel bit was varied to see the impact of better and worse chip clearance ability. Increasing number of flutes was found to positively impact peak weld strength to a point. Optimal number of flutes was found to be different for each type of testing. It was found that there was an optimal bit head to bit shank diameter ratio that optimized peak weld strength. Again the optimal diameter was different for each test. Bits of different diameters were created and then tested to measure the impact of varying shank diameters on peak weld strength. It was found that there was a strength tradeoff between two localized joint areas in diameter testing. Decreasing the shank diameter increased the amount of overlap formed by the bit head over the top coupon. This shifted strength to the bit head region. While this strengthened the bit head region of the joint, strength was sacrificed in the bit-nut intersection. This tradeoff was consistently found in all test types.
3

Accomplishing a One Team Mission in Automotive Manufacturing Companies

Agozzino, Jeremy Paul 10 August 2020 (has links)
No description available.
4

VIRTUAL ERGONOMICS AND GAMING TECHNOLOGY FOR POSTURE ASSESSMENT: FROM AUTOMOTIVE MANUFACTURING TO FIREFIGHTING / VIRTUAL ERGONOMICS AND GAMING TECHNOLOGY

Kajaks, Tara January 2017 (has links)
Virtual ergonomics (VE) tools have had an impressive impact on the automotive, aviation, and defence industries. Despite the progress made in the last four decades, the tool complexity and application potential in other industries continues to invite improvement opportunities. Firefighting is an occupation with a high musculoskeletal injury burden that can benefit from innovative VE tools. This dissertation aims to: 1) improve VE tools for traditional and novel applications, and 2) identify injury risk to firefighters during fire suppression tasks. This dissertation begins by proposing a set of joint-specific and whole-body posturing guidelines for the manual manipulation of digital human models (DHMs) in the context of automotive manufacturing. Simulation accuracy improved with the implementation of posturing guidelines. These findings are useful instructions for virtual simulation ergonomists, software developers of posture prediction algorithms, and those charged with determining manufacturing ergonomics protocols. Descriptive ergonomic analyses of 48 firefighters in full bunker gear performing three common fire suppression tasks were then performed to identify the required ergonomic action needed for these tasks. Next, two VE tools (Jack and 3DSSPP) and Microsoft Kinect® 3D motion capture data were used to conduct an in-depth analysis of the most difficult task, the high-rise pack lift. The analysis included developing a methodology for modeling the external loads due to personal protective equipment. In addition to describing the firefighter injury risk exposure during common fire suppression tasks, the results highlight the strengths, limitations, and areas for further improvement of VE technology. Overall, VE tool improvements include suggesting guidelines for manual DHM posturing, understanding the strengths and limitations of using 3D motion capture gaming technology for posturing DHMs, and developing strategies to account for external loads due to personal protective equipment. Following these improvements, VE technology shows promise as an ergonomic assessment tool for firefighters. / Thesis / Doctor of Philosophy (PhD) / Virtual ergonomics (VE), which uses digital human models in virtual workstations, allows for efficient and detailed ergonomic assessments of tasks that are otherwise difficult or impossible to perform. However, more research is needed to identify tool improvements for both traditional and new applications. This work proposes, evaluates, and ultimately recommends a set of postural guidelines for the posturing of digital human models to ensure accurate simulation and subsequent assessment of real assembly-line worker movement patterns. Next, firefighter ergonomics, a relatively new application for VE tools, is introduced by first describing the injury risks associated with common fire suppression tasks. The strengths, limitations, and potential of applying VE tools to firefighting ergonomics are then highlighted through an example of simulating the high-rise pack lift task using two VE tools. Overall, the results contribute to the evolving field of VE by challenging current methodologies and highlighting new opportunities for VE tools.
5

The Feasibility of Augmenting a Fixed-Gap Bobbin Friction Stir Welding Tool with Cutters to Join Enclosed Castings

Christensen, Adam Baxter 01 June 2018 (has links)
Bobbin Friction Stir Welding (BFSW) is a new application of Friction Stir Welding (FSW) that can be used to join materials together with little to no axial forces. This eliminates the need of a backplate or anvil needed to apply counter pressure against the tool. The applications of BFSW are growing every day. This new technology is helping the automotive industry and many other industries join materials more effectively and efficiently. This technology can be used to join materials with high strength to weight ratios to make cars lighter to increase fuel efficiency. This will also greatly reduce the cost of current joining technologies.The purpose of this research is to prove the feasibility of augmenting a BFSW tool with cutters to join enclosed castings while simultaneously removing ribs and variations in thickness by (1) penetrating a BFSW tool into the material away from an edge; (2) removing any inconsistencies in the material thickness while maintaining a weld; and (3) removing a BFSW tool from the casting away from an edge leaving a clean exit hole without destroying either the casting or the tool.
6

Designing Artefacts Based on Triggers to Support Innovation and Creativity

van Morgen, Karlijn January 2018 (has links)
This master’s thesis aims to identify triggers for innovation and creativity both from theory and from practise in the context of an automotive manufacturing company. The identified triggers are then re-interpreted and used to design prototypes which aim to visualise, support, and stimulate incremental innovation. Through a design process, the prototypes are co-designed together with a group of participants from the automotive manufacturing company to explore and understand how to create prototypes that are relevant to the context. The result indicates that the prototypes do not only visualise, support, and stimulate incremental innovation but that they can also function as a foundation for radically design and develop new approaches to work; such as incorporating design thinking and a more diverse, inclusive, and creative approach to idea generation. Ultimately, the prototypes can be incentives for changing the organisation in the way the employees work and approach tasks, but the employees must learn how to use the prototypes to utilize them in the most efficient way. / Den här mastersuppsatsen har som mål att identifiera triggers av innovation och kreativitet, både hämtade ur teorin men också praktiken inom fordonstillverkningskontexten. Dessa triggers används sedan i designprocessen för att designa prototyper för ändamålet att visualisera, stötta och stimulera inkrementell innovation. Designprocessen involverar co-design tillsammans med en grupp från företaget för att utforska och bättre förstå hur vi kunnat skapa prototyper som är relevanta för kontexten. Resultatet indikerar att prototyperna inte enbart visualiserar, stöttar och stimulerar inkrementell innovation utan också kan fungera som en grund att designa och utveckla nya, radikala tillvägagångssätt att arbeta på inom organisationen; exempelvis genom att införliva design thinking och i högre grad mångfaldiga, inkluderade och kreativa sätt att ta sig an ide generering. Prototyperna kan vara drivsporrar till att förändra organisationen i det sätt de anställda arbetar på och tar sig an uppgifter men de anställda måste lära sig att använda prototyperna för att kunna dra nytta av dem på bästa sätt.
7

Knowledge based system implementation for lean process in low volume automotive manufacturing (LVAM) with reference to process manufacturing

Mohamed, N.M.Z.Nik, Khan, M. Khurshid 04 August 2011 (has links)
Yes / Global manufacturing industry mostly depends on new product development and processes to become competitive. The product development process for automotive industry is normally complicated, lengthy, expensive, and risky. Hence, a study of lean manufacturing processes for low volume manufacturing in automotive industry is proposed to overcome this issue by eliminating all wastes in the lengthy process. This paper presents a conceptual design approach to the development of a hybrid Knowledge Based (KB) system for lean process in Low Volume Automotive Manufacturing (LVAM). The research concentrates on the low volume processes by using a hybrid KB system, which is a blend of KB system and Gauging Absences of Pre-requisites (GAP). The hybrid KB/GAP system identifies all potential waste elements of low volume process manufacturing. The KB system analyses the difference between the existing and the benchmark standards for lean process for an effective implementation through the GAP analysis technique. The proposed model explores three major lean process components, namely Employee Involvement, Waste Elimination, and Kaizen (continuous improvement). These three components provide valuable information in order for decision makers to design and implement an optimised low volume manufacturing process, but which can be applied in all process manufacturing, including chemical processing.
8

Toward a Production Ready FBJ Process for Joining Dissimilar Combinations of GADP 1180 Steel and AA 7085-T76

Shirley, Kevin Alexander 01 March 2018 (has links)
Friction Bit Joining (FBJ) is a new technology that can be used to join dissimilar materials together. This ability makes it a good candidate for creating light weight structures for the automotive industry by combining lightweight materials such as aluminum to stronger materials like advanced high-strength steels. The automotive industry and many other industries have great interest in reducing structure weight to increase fuel efficiency. The purpose of this research is to make FBJ of GADP 1180 to AA 7085-T76 a production ready process by (1) better understanding the effects of process parameters, bit design and tool design on joint strength and reliability especially as they relate to different joint configurations; (2) determining if consecutive FBJ joints on a part will be additive in strength; (3) improving surface finish for better coating adhesion so that joints can be made to withstand extended corrosion testing; and (4) determining the failure modes and fatigue life of joint components at high and low load amplitudes. No universal parameter set for optimizing peak load for T-peel, cross tension, and lap-shear tension configurations were found. Due to the extreme load conditions of T-peel and the smaller margin of safety it is better to optimize for T-peel. However, strength and reliability were still improved across the board. Cutting features and tapered shanks were found to not always be necessary. Removing cutting features from the bit design increased peak weld cycle loads, but a stiffer machine can overcome this. Consecutive FBJ joints on a part are mostly additive in nature. When the weakest joint fails, its load is distributed to the remaining joints and will limit the peak load of the whole part. If all joints are "good" then the peak load will be approximately additive. Most of the stress is localized on the side of the bit opposite of the pulling direction. Failure modes in lap-shear tend to change from weld nugget pullouts in single weld specimens to aluminum material failures in multi-weld specimens. This is because of the added stiffness that additional material and welds provide to resist coupons bending and creating a peeling action. Surface finish was improved by development of a floating carbide cutting system which cut aluminum flash as it was generated around the head of the bit. A new internal drive design provided the ability to drive bits flush with the aluminum top layer if desired with minimal reductions in strength. Flush bits provided benefits in safety, cosmetics, and coating adhesion.
9

Friction Bit Joining of Dissimilar Combinations of DP 980 Steel and AA 7075

Peterson, Rebecca Hilary 01 June 2015 (has links)
Friction Bit Joining (FBJ) is a new technology that allows lightweight metals to be joined to advanced high-strength steels (AHSS). Joining of dissimilar metals is especially beneficial to the automotive industry because of the desire to use materials such as aluminum and AHSS in order to reduce weight and increase fuel efficiency. In this study, FBJ was used to join 7075 aluminum and DP980 ultra-high-strength steel. FBJ is a two-stage process using a consumable bit. In the first stage, the bit cuts through the top material (aluminum), and in the second stage the bit is friction welded to the base material (steel). The purpose of the research was to examine the impact a solid head bit design would have on joint strength, manufacturability, and ease of automation. The solid head design was driven externally. This design was compared to a previous internally driven head design. Joint strength was assessed according to an automotive standard established by Honda. Joints were mechanically tested in lap-shear tension, cross-tension, and peel configurations. Joints were also fatigue tested, cycling between loads of 100 N and 750 N. The failure modes that joints could experience during testing include: head, nugget, material, or interfacial failure. All tested specimens in this research experienced interfacial failure. Welds were also created and examined under a microscope in order to validate a simulation model of the FBJ process. The simulation model predicted a similar weld shape and bond length with 5 percent accuracy. Joints made with external bits demonstrated comparable joint strength to internal bits in lap-shear tension and cross-tension testing. Only external bits were tested after lap-shear tension, because it was determined that external bits would perform comparably to internal bits. Joints made with external bits also exceeded the standard for failure during fatigue testing. Peel tested specimens did not meet the required strength for the automotive standard. Examining specimens under a microscope revealed micro-cracks in the weld. These defects have been shown to decrease joint strength. Joint strength, especially during peel testing, could be increased by reducing the presence of micro-cracks. The external bit design is an improvement from the internal bits for manufacturability and ability to be automated, because of the less-expensive processes used to form the bit heads and the design that lends to ease of alignment.
10

A Study of the Effect of Load and Displacement Control Strategies on Joint Strength in Friction Bit Joining of GA DP 1180 Steel and AA 7085-T71

Berg, Taylor George 10 December 2021 (has links)
Friction Bit Joining (FBJ) is a new technology that can be used to join dissimilar materials together. This ability makes it a good candidate for creating lightweight structures for the automotive industry by combining lightweight materials such as aluminum to stronger materials like advanced high-strength steels. The automotive industry is putting significant effort into interest in reducing vehicle structure weight to increase fuel efficiency and reduce greenhouse gas emissions. Joining of dissimilar materials is a challenge they face in the light weighting the body of the vehicle. The purpose of the current research is to employ FBJ in the joining of a very challenging material combination: GA DP 1180 to AA 7085-T71. In accomplishing this purpose, the goal is to move FBJ toward a more production ready process by better understanding the effects of tooling, bit design, and process parameters on joint strength and reliability as they relate to load profiles captured during the joining process. It was found that the joint strength variation was influenced strongly by the hardness and the geometric consistency of the consumable bits. Bit hardness below 45 HRC led to joint strength that was less than the required specification (5kN in lap shear tension, and 1.5kN in cross-tension and T-peel). Variation in bit height and diameter also led to excessive scatter in joint strength values, where it was not possible to meet the standard for 10 consecutive specimens (for each of the three tests). Implementation of high-speed data acquisition (1000Hz) enabled the capture of load curve profiles generated during FBJ. Load curve profiles were correlated with destructive testing results to discover the impact of process parameter combinations. Analysis of load curve profiles led to improvements in parameter selections of spindle speeds (revolutions per minute) and spindle feed-rates (inches per minute). Process parameters of 5000 RPM and 15 IPM reduced variation in load-curve profiles and destructive testing. Satisfactory joint strength was achieved in lap shear tension, cross-tension, and T-peel testing configurations with values of 10.1 kN, 4.1 kN, and 1.8 kN, respectively. The presence of wet adhesive had little impact on joint performance. Finally, the analysis of a load-curve profiles resulted in a criterion that allowed for distinguishing "good" welds from "bad" ones, where a threshold load of 6kN, or higher, during the dwell phase of welding was required in order to meet joint strength standards.

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