Análise da ruptura de cabos de protensão em vigas mistas de aço e concreto protendidas

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2019.Grande parte das estruturas na América Latina faz uso do concreto armado e protendido. O aço, entretanto, mostra-se como uma alternativa de utilização, seja isoladamente, seja em associação com estruturas de concreto, configurando as estruturas mistas de aço e concreto. O uso de estruturas de aço apresenta diversas vantagens, como redução do tempo da obra, redução ou eliminação da necessidade de escoramento, diminuição da altura da seção transversal e redução no peso-próprio. Para maior otimização pode-se recorrer ao expediente da protensão, que possibilita redução da altura dos perfis. A protensão também pode prover reforço para estruturas antigas. Deve-se ressaltar que no caso de vigas metálicas, a protensão deve, necessariamente ser externa. Portanto, deve-se tomar cuidado com relação a problemas de acidentes contra os cabos, podendo ocasionar sua ruptura e consequente ruína da estrutura. Este estudo objetiva analisar a ruptura dos cabos de protensão para o perfil I anti-simétrico (mesa inferior menor que mesa superior). A análise foi realizada por meio de formulação analítica do fenômeno com base na Transformada de Laplace e Funções de Heaviside, posteriormente validadas com modelagem numérica no programa ANSYS. Os resultados mostraram boa concordância entre os modelos analítico e numérico.A substantial portion of structures in Latin America uses either reinforced concrete or prestressed concrete. Steel, however, appears as an alternative, alone, or in association with concrete, the so-called composite concrete-steel structures. A few advantages of the use of concrete-steel structures are: reduction in construction time, reduction or even elimination the need for propping, a decrease in the cross section height, and reduction in overall self-weight. For better optimization, prestress appears as an option that allows a greater decrease in the height of the section. It can also provide reinforcement for old structures. It should be emphasized that in the case of steel beams, prestress must be applied externally. Therefore, caution has to be taken with respect to accidents against the tendons, which can cause rupture of the cables and consequent failure of the structure. This study aims to analyse the rupture of prestressing tendons for assimetrical I section, with superior flange wider than inferior flange. The analysis will be carried out by means of analytical formulation through the use of Laplace Transforms and Heaviside functions, and then validated with numerical modeling in the ANSYS simulation software. The results showed concordance between both models

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data