• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 99
  • 36
  • 6
  • Tagged with
  • 141
  • 51
  • 42
  • 37
  • 34
  • 28
  • 26
  • 19
  • 18
  • 16
  • 16
  • 16
  • 16
  • 16
  • 16
  • 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.
141

Sistema computacional para análise de fluxo através das barragens de terra e rock-fill utilizando elementos finitos. / Computational system for flow analysis through earth and rock-fill dams using finite elements.

SOUSA, João Augusto Barbosa . 06 November 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-06T00:47:32Z No. of bitstreams: 1 JOÃO AUGUSTO BARBOSA SOUSA - DISSERTAÇÃO PPGECA 1991..pdf: 20226382 bytes, checksum: eba1c136d21ab9224bc5d71dd5640c90 (MD5) / Made available in DSpace on 2018-11-06T00:47:32Z (GMT). No. of bitstreams: 1 JOÃO AUGUSTO BARBOSA SOUSA - DISSERTAÇÃO PPGECA 1991..pdf: 20226382 bytes, checksum: eba1c136d21ab9224bc5d71dd5640c90 (MD5) Previous issue date: 1991-03-06 / Este trabalho consiste no desenvolvimento e apresentação de uma sistemática de cálculos que, utilizando elementos finitos e microcomputadores, permite dimensionar e posicionar fenômenos hidráulicos no interior dos sistemas, maciços, fundações e dispositivos de proteção das barragens de terra e rock-fill, quando esses se encontrarem em regime permanente e submetidos a variações de fluxo, nas fases de construção, operação e manutenção. Buscando-se atingir ao objetivo pretendido, elaborou-se um sistema de programas e arquivos que, integrados, possibilita a utilização do Programa FPM500 de modo prático. O FPM500 trata dos escoamentos nos meios porosos, confinados e não confinados, nos sistemas bidimensional e/ou tridimensional com simetria de revolução. Entretanto, apesar de flexível, para o seu emprego, era grande a quantidade de dados de entrada a serem informados, diretamente, pelos usuários e, por ser acoplado a um gerador de malhas, aumentava o número de informações, levando esse, na versão original, a ser processado somente em computadores de grande porte. Na sistemática apresentada, inicia-se com um arquivo contendo informações relativas aos blocos estruturais. Um programa acoplado a um renumerador processa essas e renumera todos os nós da malha de elementos, assim reduzindo as bandas das matrizes de fluxo e otimizando memórias em microcomputadores. Este recurso possibilita substancial ganho em velocidade, em busca das soluções dos sistemas com múltiplas equações lineares simultâneas. Os dados resultantes deste processamento permitem a confecção de malhas integradas por elementos triangulares e/ou quadrilaterais lineares, no sistema bidimensional simultâneas. Os dados resultantes deste processamento permitem a confecção de malhas integradas por elementos triangulares e/ou quadrilaterais lineares, no sistema bidimensional / This dissertation deals with the development and the presentation as well of a systematics of calculus that, by making use of finite elements and microcomputers alike, enables both to settle the dimension and the position of hydraulic phenomena in the interior of systems, massifs, foundations and protection organs for earth and rock-fill dams, when the latter are to be found at everlasting rate and suodued to flood variations in the construction, operation and maintenance phases. In the search for an intended purpose, a program and files system was carried out which, once integrated, makes feasible the utilization of Program FPM500 in a practical way. Such a program (viz., FPM500) is related to flows in porous enviroments, restrained or no restrained, in bidimensional and/or tridimensional systems with revolution symmetry. However, despite being flexible for its usage, the quantity of input data to be directly informed by users is huge and, on account of its being coupled to a network generator, it increased the number of informations so that it, at the long run, finished being processed only mainframe computers. In the presented systematics, one begins with a file encompassing informations related to structural blocks. A program coupled to a renumerator processes them and numbers again ali nodes of the elements network by so reducing the flow matrix bandwidth therefore de creasing storage requirements in the computer. Such resource enabls a substantial gain in speed in the systems with mutiple linear simultaneous equations. The data arising from that processing enable the making of integrated networks by triangular and/or four-sided linear elements in the bidimensional system. In another program, the data necessary to the studies of different hydric systems are completed. Therein the outputs of GETOP Program are resettled, the refomations dealing with the boundary conditions and with structural blocks. Such data are kept in files, appropriately shaped in a given format in order to feed Program FPM500. Program FPM500 processes ali elaborated informations as it calculates loads, pressures and flows by providing a report with informations likely to interest studies of hydraulic stability of earth and rock-fill dams. The presented methodology has the advantage to exclude the great amount of blunders committed on input data, in the usage of finite elements thrregh conventional processes. There is also the possibility of a future implementation of graphic programs for drawing element networks thrugh plotter or video. Thus, one is afforded to state that such a systematic, beyond facilitating the calculi, presents confidence and speed as it can be used in different practical equations, the aim of which is likely to be the previous knowledge of the conditions of hydraulic stability in those structures.

Page generated in 0.0504 seconds