8,609 research outputs found

    Buckling Testing and Analysis of Honeycomb Sandwich Panel Arc Segments of a Full-Scale Fairing Barrel Part 1: 8-Ply In-Autoclave Facesheets

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    Four honeycomb sandwich panels, representing 1/16th arc segments of a 10-m diameter barrel section of the heavy lift launch vehicle, were manufactured under the NASA Composites for Exploration program and the NASA Space Launch Systems program. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.000 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: inautoclave IM7/977-3 and out-of-autoclave T40-800b/5320-1. Smaller 3.00- by 5.00-ft panels were cut from the 1/16th barrel sections. These panels were tested under compressive loading at the NASA Langley Research Center. Furthermore, linear eigenvalue and geometrically nonlinear finite element analysis was performed to predict the compressive response of the 3.00- by 5.00-ft panels. This manuscript summarizes the experimental and analytical modeling efforts pertaining to the panel composed of 8-ply, IM7/977-3 facesheets (referred to Panel A). To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear models yield good qualitative and quantitative predictions. Additionally, it was predicted correctly that the panel would fail in buckling prior to failing in strength. Furthermore, several imperfection studies were performed to investigate the influence of geometric imperfections, fiber misalignments, and three-dimensional (3 D) effects on the compressive response of the panel

    Buckling Testing and Analysis of Honeycomb Sandwich Panel Arc Segments of a Full-Scale Fairing Barrel

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    Four honeycomb sandwich panel types, representing 1/16th arc segments of a 10-m diameter barrel section of the Heavy Lift Launch Vehicle (HLLV), were manufactured and tested under the NASA Composites for Exploration program and the NASA Constellation Ares V program. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.000 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: in-autoclave IM7/977-3 and out-of-autoclave T40-800b/5320-1. Smaller 3- by 5-ft panels were cut from the 1/16th barrel sections. These panels were tested under compressive loading at the NASA Langley Research Center (LaRC). Furthermore, linear eigenvalue and geometrically nonlinear finite element analyses were performed to predict the compressive response of each 3- by 5-ft panel. This manuscript summarizes the experimental and analytical modeling efforts pertaining to the panels composed of 6-ply, IM7/977-3 facesheets (referred to as Panels B-1 and B-2). To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear models yield good qualitative and quantitative predictions. Additionally, it was correctly predicted that the panel would fail in buckling prior to failing in strength. Furthermore, several imperfection studies were performed to investigate the influence of geometric imperfections, fiber angle misalignments, and three-dimensional (3-D) effects on the compressive response of the panel

    Curso de produção de documentos digitais utilizando o latex

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    A elaboração de documentos digitais na Universidade é de grande importância para o registro e divulgação das informações acadêmicas, incluindo administrativas. Existem diversas ferramentas computacionais que são usadas para essa finalidade, como por exemplo a suíte de aplicativos Microsoft Office e a suíte de aplicativos para escritório LibreOffice. Contudo, uma ferramenta que tem sido cada vez mais empregada na edição de trabalhos é o LaTeX, que consiste em um programa para a preparação de textos impressos de alta qualidade, especialmente textos técnicos, científicos e matemáticos. Permite o uso de modelos de documentos prontos empregando padrões de escrita como o Associação Brasileira de Normas Técnicas (ABNT). O LaTeX vem se tornando uma referência para a comunicação e publicação de documentos científicos, sendo utilizado em livros, artigos, teses e documentos da administração pública. Neste cenário, conhecer essa tecnologia torna-se necessário e este curso capacitou em 2017 mais aproximadamente 100 pessoais, e em 2018 está capacitando mais 100 pessoas, em especial discentes, docentes, TAES e diversos membros da comunidade externa, no uso desta tecnologia de processamento de documentos digitais. Por fim, ressalta-se de 2017 para 2018 notou-se aumento da demanda devido a consciência da comunidade com relacão ao uso e conhecimento dessa tecnologia

    Tactical Athletes: An Integrated Approach to Understanding and Enhancing the Health and Performance of Firefighters-in-Training

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    International Journal of Exercise Science 8(4): 341-357, 2015. In an effort to reduce the rates of firefighter fatality, injury, and workplace stress, there has been a call for research to advance knowledge of firefighting performance and injury prevention. Physical and psychological variables important to firefighter health and performance have been identified, yet the interrelated nature of these variables has been overlooked. Given the overlap between the physical and psychological demands of firefighting and sport, and given that an integrated framework has been used in the sport domain to guide athlete health and performance research and practice, firefighter organizations could benefit from adopting a sport-based, integrated model of firefighter training and performance management. Guided by the Meyer Athlete Performance Management Model (MAPM), the purposes of the current study were to: (a) describe the physical and psychological characteristics of firefighters-in-training (i.e., cadets and recruits), and (b) explore relationships between the physical and psychological variables associated with health and performance. Firefighters-in-training employed by a Midwestern area fire department in the United States (N = 34) completed a battery of physical and psychological assessments at the department’s Fire and Safety Academy building. Results of the current study revealed significant correlations between several of the physical and psychological characteristics of firefighters-in-training. These results, along with the multidimensional data set that was also established in the current study, provide preliminary evidence for the use of a sport-based integrated performance model such as the MAPM to guide training and performance research in firefighter populations

    Buckling Testing and Analysis of Honeycomb Sandwich Panel Arc Segments of a Full-Scale Fairing Barrel: Comparison of In- and Out-of-Autoclave Facesheet Configurations

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    Four honeycomb sandwich panels, representing 1/16th arc segments of a 10-m diameter barrel section of the Heavy Lift Launch Vehicle, were manufactured and tested under the NASA Composites for Exploration and the NASA Constellation Ares V programs. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.0 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: in-autoclave IM7/977-3 and out-of-autoclave T40-800b/5320-1. Smaller 3 ft. by 5 ft. panels were cut from the 1/16th barrel sections and tested under compressive loading. Furthermore, linear eigenvalue and geometrically nonlinear finite element analyses were performed to predict the compressive response of each 3 ft. by 5 ft. panel. To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear models yielded good qualitative and quantitative predictions. Additionally, it was correctly predicted that the panel would fail in buckling prior to failing in strength. Furthermore, several imperfection studies were performed to investigate the influence of geometric imperfections, fiber angle misalignments, and three-dimensional effects on the compressive response of the panel

    Search for the standard model Higgs boson at LEP

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