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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

Characterization of Soccer Ball Parameters for the Manufacturing of Protective Headbands and the Frequency Domain Evaluation of Football Helmets

Nicolas Leiva (6578075) 10 June 2019 (has links)
An increase of 153,375 to 248,418 traumatic brain injuries (TBI) due to incidents in sports and recreation activities has been reported in the past couple of years in the US alone. These are grounds for concern for athletes partaking in sports with a high incidence of TBI’s such as football and soccer. The latter, traditionally not classified as a contact-sport, has attracted research due to participants using their head as an instrument for heading. Voluntary heading, in combination with lenient laws and regulations concerning TBI expose how soccer players are easily at risk of injury. On the other hand football, an aggressive sport by nature, has brought attention to the possible neurocognitive and neurophysiological ramifications of repetitive subconcussive impacts. One of these is in the form of a progressive neurodegenerative pathology known as chronic traumatic encephalopathy (CTE). A priori reasons revealed, led to a need to characterize the most important variables involved in ball-player interactions within soccer simulated gameplay. By understanding these, it would be possible to obtain parameters to design and manufacture new composite-material based protective headgear unlike products that are commercially available nowadays. In addition, development of a testing protocol focused on frequency domain variables - transmissibility and mechanical impedance - would allow to evaluate the performance of football helmets. A focus would be set on low impacts categorized as subconcussive impacts. Incoming velocity and inflation pressure were identified as the most influential variables affecting the peak impact force of a soccer ball. An innovative 6-layer carbon fiber headband, with silicone padding, was manufactured that out-performed existing headgear at attenuating peak linear acceleration. Lastly, quantification of the transmissibility and mechanical impedance indicated poor performance of football helmets below 60 Hz.
2

Design for Additive Manufacturing – Application System based on Design Methodology in Industrial Standards

Günther, Florian, Koch, Alexander 09 October 2024 (has links)
Over the past few decades, additive manufacturing (AM) evolved from rapid prototyping (RP) into mature manufacturing technologies for complex high-performance end use products. The transition in the industrial application of these technologies necessitates a design methodology tailored to the potentials and restrictions of AM. This contribution presents a new application system for opportunistic and restrictive component design, which can be integrated into design for additive manufacturing (DfAM) methodologies. For the first time, methods for AM part design are being drawn from standards and integrated into an application system, supporting professionals in the practical implementation of design for additive manufacturing methods.

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