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    3-D Seismic Evaluation of on Grade Cylindrical Flexible Storage Tanks Considering Soil-Structure Interaction

    , M.Sc. Thesis Sharif University of Technology Andalib, Reza (Author) ; Rahimzadeh Rofooei, Fayaz (Supervisor)
    Abstract
    The circular flexible cylindrical liquid tanks usually are made of steel or aluminum and in majority of cases are built on grade due to its economic advantages. The most important part of a safe design of a storage tanks is the accurate estimation of the seismically induced lateral forces that should be transferred to its base through the tank shell and its support. Seismic behavior of liquid storage tanks is quite different from regular buildings and industrial structures due to its nonlinear behavior caused by complex distribution of hydrodynamic pressure, buckling of its walls, etc.. Moreover, the effect of rocking motion caused by the under laying soft soil, on its response parameters... 

    Spectral Element Simulations of Wave Propagation in Porous Fluid-Saturated Media

    , M.Sc. Thesis Sharif University of Technology Moezzi, Mohammad Javad (Author) ; Naghd Abadi, Reza (Supervisor) ; Asghari, Mohsen (Supervisor) ; Mazaheri, Hashem (Co-Advisor)
    Abstract
    The aim of this work is numerical analysis of wave propagation in earth by using spectral element method for single and multi phase with application in oil industry. In this method, numerical solution has high accuracy due to using high order polynomials and appropriate integration points. Also, the mass matrix is diagonal by using this method which results in considerable decrease in computational cost with respect to finite element method.
    The wave propagation in the mentioned models is studied by many researchers. The main problem in petroleum industry is large dimension of the model which results in high computational costs. Thus, using the proper numerical approach for these... 

    Evaluation of Seismic Response Parameters in On-Grade Cylindrical Steel Storage Tanks Considering Wave Propagation in Under Laying Soil

    , M.Sc. Thesis Sharif University of Technology Rezaei, Mohamad Hadi (Author) ; Rahimzadeh Rofooei, Fayaz (Supervisor)
    Abstract
    The circular flexible cylindrical liquid tanks are usually made of steel or aluminum and in majority of cases are built on grade due to its economic advantages. The most important part of a safe design of storage tanks is the accurate estimation of the seismically induced lateral forces that should be transformed to its base through the tank shell and its support . seismic behavior of the liquid storage tank is quite different from regular buildings industrial structures due to its nonlinear behavior caused by complex distribution of hydrodynamic pressure, buckling of its wall, etc.. moreover, the effect of rocking motion caused by under laying soft soil, on its response parameter could be... 

    The Effect of Dam-Foundation Interaction on The Seismic Behavior of Concrete Gravity Dams Using Semi-Infinite Elements

    , M.Sc. Thesis Sharif University of Technology Abbasnezhad, Hamed (Author) ; Ghaemian, Mohsen (Supervisor) ; Toufigh, Vahab (Supervisor)
    Abstract
    Owing to severe consequences of dams’ failure, studying the seismic behavior of concrete dams with dam-reservoir-foundation interaction consideration is of paramount importance. Several researches have focused their studies on realistic modeling of dams in terms of their dynamic behavior in the past. The nature of dam’s foundation is a semi-infinite continuum which requires the accurate modelling of structure-foundation interaction. Given that simulation of foundation as a semi-infinite continuum is not feasible by finite element, this infinite continuum should be curtailed with specific considerations in the curtailed parts to avoid the reflection of the outgoing waves. An alternative... 

    Seismic performance evaluation of a jointed arch dam

    , Article Structure and Infrastructure Engineering ; Volume 12, Issue 2 , 2016 , Pages 256-274 ; 15732479 (ISSN) Alembagheri, M ; Ghaemian, M ; Sharif University of Technology
    Taylor and Francis Ltd  2016
    Abstract
    Seismic performance and safety of a jointed arch dam, as an arch-shaped mass concrete structure, are investigated through the nonlinear incremental dynamic analysis. In this way, 12 proper ground motions are selected, each of them is scaled to 12 successively increasing intensity levels and applied to the dam. Three and seven contraction joints are inserted within the dam body, and stage construction is taken into account. Several main assumptions including dam–reservoir–foundation dynamic interaction, absorbing boundary conditions at the far-ends of the reservoir and foundation, and material and joint nonlinearities are considered. The failure modes of the dam are determined according to... 

    Multidimensional modeling of the stenosed carotid artery: A novel CAD approach accompanied by an extensive lumped model

    , Article Acta Mechanica Sinica/Lixue Xuebao ; Vol. 30, issue. 2 , 2014 , p. 259-273 Kashefi, A ; Mahdinia, M ; Firoozabadi, B ; Amirkhosravi, M ; Ahmadi, G ; Saidi, M. S ; Sharif University of Technology
    Abstract
    This study describes a multidimensional 3D/lumped parameter (LP) model which contains appropriate inflow/outflow boundary conditions in order to model the entire human arterial trees. A new extensive LP model of the entire arterial network (48 arteries) was developed including the effect of vessel diameter tapering and the parameterization of resistance, conductor and inductor variables. A computer aided-design (CAD) algorithm was proposed to efficiently handle the coupling of two or more 3D models with the LP model, and substantially lessen the coupling processing time. Realistic boundary conditions and Navier-Stokes equations in healthy and stenosed models of carotid artery bifurcation... 

    Investigating the instabilities of the TLM method using a state-space approach

    , Article 2007 Workshop on Computational Electromagnetics in Time-Domain, CEM-TD, Perugia, 15 October 2007 through 17 October 2007 ; 2007 ; 142441170X (ISBN); 9781424411702 (ISBN) Mostafanezhad, I ; Banai, A ; Farzaneh, F ; Sharif University of Technology
    2007
    Abstract
    Stability has been one of the major issues of time-domain numerical methods used for solving Maxwell equations. This problem takes a more severe form when additional algorithms are introduced to the computation domain (e.g. Absorbing Boundary Conditions-ABCs). There are a number of methods for investigating the stability of a simulation. In this article the problem of stability of ABCs, has been tackled through a control system's state-space point of view. Thus, occurrence of instability in a simulation can be predicted. © 2007 IEEE