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EE - Escola de Engenharia

URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/512

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1989 - 198911990 - 19984

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Autor: search.filters.author.Araújo, José Milton deData final: 1999

Resultados da Pesquisa

Agora exibindo 1 - 5 de 5
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    On stochastic finite elements for structural analysis
    (1994) Araújo, José Milton de; Awruch, Armando Miguel
    This paper considers the stochastic finite element analysis of structures resulting from random spatial variability of material properties, when they are subjected to loads of deterministic nature. Direct Monte Carlo simulation, Monte Carlo with Neumann expansion of the stiffness matrix and Taylor series expansion combined with the classical finite element approach are applied and compared with respect to accuracy and computational efficiency. Dynamic and non-linear problems are also included.
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    Optimization of newton-raphson methods in RC nonlinear analysis
    (1989) Araújo, José Milton de
    The Newton-Raphson method is used for the nonlinear analysis of reinforced concrete structures. Three extrapolation formulas for displacements are developed in order to accelerate the convergence of the iterative scheme. The computing time and the number of necessary iterations for each proposed alternative are compared.
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    An objective cracking criterion for the analysis of concrete dams
    (1996) Araújo, José Milton de; Awruch, Armando Miguel
    Cracking analysis by the finite element method may be accomplished using a continuum damage theory, but results are strongly affected by the adopted finite element mesh. A reduced tensile strength has been proposed in order to obtain objective results; however this approach may still be dependent on the adopted finite element mesh. An alternative model for concrete cracking, which is independent of the finite element mesh and especially suitable for the analysis of concrete dams, is proposed in this work.
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    Probabilistic finite element analysis of concrete gravity dams
    (1998) Araújo, José Milton de; Awruch, Armando Miguel
    A methodology for the probabilistic analysis of concrete gravity dams is presented, Concrete properties and seismic excitation are considered as random variables. The seismic excitation is considered as a non-stationary stochastic process which is artificially generated. Concrete properties have random variations over the spatial domain. Structural response is obtained employing the finite element method to solve the equations of motion of the coupled system dam-reservoir-foundation. Structural safety is evaluated with respect to the main failure modes (cracking, concrete crushing and sliding at the dam-foundation interface) using the Monte Carlo method.
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    Cracking safety evaluation on gravity concrete dams during the construction phase
    (1998) Araújo, José Milton de; Awruch, Armando Miguel
    The cracking phenomenon in concrete gravity dams during the construction phase is analysed in this work. Stresses due to the self-weight of the dam, thermal gradients, creep and drying shrinkage are computed, taking into account the different stages of the construction process. A twodimensional constitutive model considering time dependent and temperature dependent mechanical properties is adopted for the concrete. Safety against cracking is obtained using a criterion independent of the finite element mesh.