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    Analyzing and Modeling of Semi-hinged Connections in Steel Structure

    , M.Sc. Thesis Sharif University of Technology Haji kazemi, Mohsen (Author) ; Mofid, Massoud (Supervisor)
    Abstract
    Double angle connections, which are welded to the beam web and bolted to the column flange, are usually used to make hinged or semi-hinged connections. Several models are presented in this study whose geometrical properties are different. The finite element software package is used to develop the finite element analysis of the connections. An analytical method is presented that can be used to determine the behavior and deformation for this type of connection. The correctness of Moment-rotation curves of finite element analysis for each connection has been ascertained by comparison, using analytical technique; and a very good agreement has been obtained  

    A Parametric Study on Application and Analysis of Beam to Column "Reversed Channel" Connection in Tubular Systems

    , M.Sc. Thesis Sharif University of Technology Kokabi, Sina (Author) ; Mofid, Massoud (Supervisor)
    Abstract
    Today steel tubular systems are used more than before, especially in recent years. A difficulty with this type of systems is making beam to column connections using bolts due to no access to holes of bolts from the inside of tube or hollow circular column. Reverse channel connection is devised and introduced to prevail this problem. Access to holes in this connection is from the inside of channel. In this connection, the web of the channel is connected to steel beam using bolts and the two legs of channel is welded to face of tube column.
    This type of connection does include some innovations; not too many researchers work on different versions of this connection. This thesis provides an... 

    Modeling Moment-Rotation (M-@)Curve for Rectangular Hollow Section (RHS)Splice Beam Connection Subjected to Bending Moment and Axial Force

    , M.Sc. Thesis Sharif University of Technology Kazemi Sangdehi, Sahar (Author) ; Mofid, Masood (Supervisor)
    Abstract
    The study of bolted moment end-plate connections, both beam to column and beam to beam connections, is quite general and standard nowadays. Buildings which utilize such connections are widely being used and the reorganization of their significant benefits is growing. The research work reported in this thesis presents the results of several parametric analyses to determine the moment–rotation curve of bolted moment end-plate connections utilizing Rectangular Hollow Sections (RHS) and two rows of bolts using Finite Element Modeling (FEM). Previous experimental studies have focused on the moment-rotation relationship under pure bending. This project particularly involves further numerical... 

    A Numerical Investigation on Ultimate Strength of Steel Plate Shear Walls Utilizing Various Boundary Frame Elements and Different In-fill Plate Thicknesses

    , M.Sc. Thesis Sharif University of Technology Eghbali Farkoush, Vahid (Author) ; Khalu, Alireza (Supervisor)
    Abstract
    In this thesis different steel plate shear walls have been investigated using ABAQUS software. These investigations have been focused on various topics, including both boundary frame elements and also the in-fill plate. The main results have been gathered by utilizing different steel plate thicknesses and different boundary frame elements. In order to achieve a better understanding of the effects of both of these elements, various aspect ratios have also been investigated. Moment of inertia has been noted as the main property of both beams and columns used in SPSW. Comparison of the gained results is noteworthy. They show a variety of changes in the load-displacement diagrams, due to changes... 

    Corrugated Steel Shear Walls with and Without Openings, with Regard to Different Angles of Corrugation

    , M.Sc. Thesis Sharif University of Technology Farzampour, Alireza (Author) ; Mofid, Masoud (Supervisor)
    Abstract
    The widespread usage of corrugated steel plates as girders and steel shear walls necessitates the need for further investigation of theseefficient structural members. Having significant initial stiffness, high capability of energy dissipation and special geometry are the fundamental reasons for this study. The nonlinear behavior of trapezoidal corrugated steel shear walls with rectangular opening has been studied in this thesis. A series of corrugated and simple shear walls with and without opening regarding different angles of corrugation and different infill plat thicknesses have been investigated. This analytical study was conducted to compare the initial stiffness, ultimate strength,... 

    On The Non-Linear Behavior of Continuous Beam to Column Connection

    , M.Sc. Thesis Sharif University of Technology Rahmani, Ahmad (Author) ; Moghadam, Hasan (Supervisor)
    Abstract
    A special steel beam-to-column connection, named Khor-jini, is commonly used for steel framing system in Iran. In this system, two continuous beams are passed next to the columns and are connected to the column side using seated brackets.This type of connection has been common in Iran from the late past. Unfortunately, the seismic behavior of Khorjini frames had not been sufficiently studied prior to Manjil Earthquake of 1990. Due to very large damages which occurred in steel structures especially in connections during the said earthquake, the seismic behavior of this type of connection was studied and some of its weak points were recognized.In this study non-linear... 

    Parametric Investigation and Finite Element Modeling of an Innovative Semi-Rigid Beam to Column Connection under Monotonic Loading

    , M.Sc. Thesis Sharif University of Technology Ghaffari, Yousef (Author) ; Mofid, Masoud (Supervisor)
    Abstract
    This thesis presents the development of a Finite Element Model (FEM) for a new type of Beam-Column Semi-Rigid steel connection. This connection consists of a steel semi cylinder connected to a plate and inserted on the top and bottom of the beam connecting it to the column by welding. It seems that changing the geometry of the semi cylinders and their weld lengths can have a great influence on the rigidity or flexibility of the connection. Therefore, meaningful categories of the connection with different semi cylinder geometries and weld lengths have been modeled and investigated by means of a Finite Element Modeling software ABAQUS, and their moment-rotation curves were driven. Also the... 

    Investigation and Modeling of a New type of Semi-Rigid, Steel Beam-Column Connection under Monotonic Loading

    , M.Sc. Thesis Sharif University of Technology Taheri, Ehsan (Author) ; Mofid, Massoud (Supervisor)
    Abstract
    This thesis presents the investigation and development of a Finite Element Model (FEM) for a new type of Beam-Column Semi-Rigid steel connection. One of the main parts of this connection is a steel T profile inserted on top of a beam connecting it to a column by bolts. It seems that changes in the geometry of the T profile and its bolt positions can have a great influence on the rigidity or flexibility of the connection. Therefore, meaningful categories of the T profile geometry with different bolt positions have been modeled and analyzed by means of a Finite Element Modeling software ABAQUS, and their moment-rotation curves were driven. Also the Initial and Nonlinear Stiffness and the... 

    Experimental study on cyclic behavior of trapezoidally corrugated steel shear walls

    , Article Engineering Structures ; Volume 48 , March , 2013 , Pages 750-762 ; 01410296 (ISSN) Emami, F ; Mofid, M ; Vafai, A ; Sharif University of Technology
    2013
    Abstract
    This paper presents the research works on the cyclic behavior of trapezoidally corrugated as well as unstiffened steel shear walls. A series of experimental studies were carried out on the half-scale, one-story, single-bay steel shear walls with unstiffened and trapezoidally corrugated panels. This experimental study was conducted to compare the stiffness, strength, ductility ratio and energy dissipation capacity of three different steel shear walls: unstiffened, trapezoidally vertical corrugated and trapezoidally horizontal corrugated. Gravity loads were not applied at the top of the walls and horizontal load was applied at the top of each specimen. Loading sequence was applied as... 

    Parametric analyses on the initial stiffness of the SHS column base plate connections using FEM

    , Article Engineering Structures ; Volume 34 , 2012 , Pages 363-370 ; 01410296 (ISSN) Khodaie, S ; Mohamadi-shooreh, M. R ; Mofid, M ; Sharif University of Technology
    Abstract
    Bolted Column Base Plate (BCBP) connections are widely used to connect steel columns to the concrete foundations. This paper conducts a parametric study on the initial stiffness of bolted base plate with Square Hollow Section (SHS) column connection, through an extended 3-D Finite Element Modeling (FEM). Different features of the connection such as material behavior, geometric details, typical contact phenomena and large displacements are also considered in the modeling. A comparison between experimental test and FEM is carried out to illustrate the ability of the numerical method to simulate the connection behavior. An analytical explanation on the initial stiffness of the connection is... 

    New modeling for moment-rotation behavior of bolted endplate connections

    , Article Scientia Iranica ; Volume 18, Issue 4 A , August , 2011 , Pages 827-834 ; 10263098 (ISSN) Mohamadi Shoore, M. R ; Mofid, M ; Sharif University of Technology
    2011
    Abstract
    A new exponential model to depict the moment-rotation (M-θ) relationship of Bolted Endplate Connections (BEC) is proposed. The proposed model represents an approach to the prediction of M-O curves, taking into account the possible failure modes and the deformation characteristics of the connection elements. The presented model has three physical parameters, along with two curve-fitted factors. These physical parameters are generated from dimensional details of the connection, as well as the material properties. By employing simplified connection behavioral models to estimate the connection M-θ behavior, analytical expressions for evaluating major connection parameters, such as initial... 

    Corrigendum to: "parametric analyses on the initial stiffness of flush end-plate splice connections using FEM" [J. construct. steel res. 64 (2008) 1129-1141] (DOI:10.1016/j.jcsr.2007.09.010)

    , Article Journal of Constructional Steel Research ; Volume 65, Issue 3 , 2009 , Pages 749- ; 0143974X (ISSN) Mohamadi shooreh, M. R ; Mofid, M ; Sharif University of Technology
    2009

    Parametric analyses on the initial stiffness of flush end-plate splice connections using FEM

    , Article Journal of Constructional Steel Research ; Volume 64, Issue 10 , 2008 , Pages 1129-1141 ; 0143974X (ISSN) Mohamadi shooreh, M. R ; Mofid, M ; Sharif University of Technology
    Elsevier BV  2008
    Abstract
    Existing design procedures for steel frames have been modified during the last three decades to incorporate the semi-rigid behavior of the connections into the frame design advancement. Knowledge in initial rotational stiffness of a connection is important for the global elastic analysis of frame structures. This paper presents the results of several parametric analyses on the Initial Rotational Stiffness (IRS or Sini) of Bolted Flush End-plate Beam (BFEB) splice connections using Finite Element Modeling (FEM). The FEMs have taken into account material behavior, geometrical discontinuities and large displacements. The analyses have been calibrated to experimental results that are also... 

    Improving the mechanical characteristics of semi-rigid saddle connections

    , Article Journal of Constructional Steel Research ; Volume 186 , 2021 ; 0143974X (ISSN) Moghaddam, H ; Sadrara, A ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    There are many steel structures in Iran with semi-rigid saddle connections. It has been observed that, during a strong earthquake, this type of connection can experience a premature fracture, which will endanger the stability of the structure. The present study endeavored to improve the mechanical characteristics including the initial stiffness, yield moment, maximum moment, crack rotation, and load transfer mechanisms of the conventional saddle connections using retrofitting methods. An experimental study was conducted on six full-scale specimens to study the effect of the retrofitting methods on the stiffness, yield moment, and maximum moment of the connection and for the prevention of... 

    Experimental and numerical evaluation of the mechanical characteristics of semi-rigid saddle connections

    , Article Structural Design of Tall and Special Buildings ; Volume 31, Issue 7 , 2022 ; 15417794 (ISSN) Moghaddam, H ; Sadrara, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2022
    Abstract
    Saddle connections are semi-rigid connections that are widely used in Iran. Many existing buildings contain this type of connection. The present study conducted full-scale experiments and used extensive numerical modeling to study the mechanical characteristics of saddle connections. The mechanical characteristics examined were the moment-transfer mechanism, initial stiffness, yield moment, maximum moment, and fracture rotation. The configuration and dimensions of the experimental and numerical specimens were chosen to be similar to those of saddle connections in existing buildings. A parametric study was conducted to determine the factors affecting the mechanical characteristics of these...