Loading...
Search for:
bolts
0.006 seconds
Total 26 records
Evaluation of the Cyclic Performance of Buckling Restrained Braces with Sliding Friction Connection
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masood (Supervisor)
Abstract
In today’s world, the use of lateral load-bearing systems, such as bracings, has become a pretty common practice. Often showing axial deformation behavior, these members exhibit proper performance under tensile loads but tend to become unstable under compressive loads. In contrast to common bracing systems, the buckling-restrained bracing (BRB) systems perform well under not only tensile loads but also compressive loads. Recent studies have paid greater deals of attention to the application of short-core BRB systems in different structures. The bracing core has been shortened to increase the core deformation and hence the energy dissipation capacity of the bracing system. In this condition,...
The Performance in Temperature Increas of Bolted Slant Endplate Connection
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
The main goal of this research is to evaluate the vertical and slant bolted endplate connections performance in steel moment frame structures under thermal effect in elastic range for two cases. In the first case, frictionless and in the second case slips with friction are considered. By finite element analysis, the connections are simulated to study the performance and verify simplified models of vertical and slant bolted endplate connections due to increase in temperature. The results of a vertical bolted endplate connection and a slant bolted endplate connection due to increase in temperature are compared the effect of slope of end plate reduction of axial force on beam is investigated....
Modeling of Connections in the Cold formed Steel Structures
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Cold-formed steel sections are lightweight materials and suitable for building construction owing to their high structural performance. Conventionally, they are used as purlins and side rails in the building envelopes of industrial buildings. The most common sections are lipped C and Z sections, and the thickness typically ranges from 1.2 to 3.2 mm, and sections with yield strengths at 280, 350 and 450 MPa are commonly available. For connection design, codes of practice for design of cold-formed steel structures only provide design rules for the load carrying capacities of individual fastenings with bolts, screws and welds while no guidance on the structural behavior of connectors such as...
Numerical Study on Bolted End-Plate Connection and The Code Limits
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Regarding the numerous casualties and financial losses due to intense earthquakes, the ductility is considered of the main importance in addition to stability, stiffness, and strength criteria of the structure’s connections. In order to enhance the seismic behavior of the structures in such severe earthquakes, design codes for steel structures have suggested special types of connections. Among them, bolted end plate connection is considered a conventional type of connection used for creating ductile semi-rigid connection.In this study, in order to simulate the behavior of this joint, a 3-D finite element model is developed in Abaqus software, in which the inelastic behavior of the materials...
An Investigation on the Behavior of Bolted Connections using Friction Drilling in Shear and Tension
, M.Sc. Thesis Sharif University of Technology ; Ahmadizadeh, Mehdi (Supervisor)
Abstract
Friction drilling or flow drilling is a method of making holes in metal sheets, in which the material is pushed with the aid of heat from friction. This procedure allows making holes in sheet metal, with a sleeve formed as the hole is created. This sleeve is then threaded and used as the nut, thus eliminating the need for access to the interior faces of hollow steel sections. On the other hand, with the development of advanced manufacturing techniques, larger and thicker hollow structural sections are becoming more popular in mid-rise and multistory structures. onsequently, flow drilling can be considered as a viable alternative for traditional drilling techniques, where the material is...
The performance of bolted slant endplate connections subjected to temperature increase
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010l ; Volume 2 , July , 2010 , Pages 207-217 ; 9780791849163 (ISBN) ; Talebi, E ; Sharif University of Technology
2010
Abstract
In this paper the main goal is to evaluate the vertical and slant bolted endplate connections performance in steel moment frame structures under thermal effect in elastic field, and by a finite element software. the connections are simulated to complete and verify simple modeling of analytical and numerical analysis of the behavior of vertical and slant bolted endplate connections due to increase in temperature. The results that are obtained from performance of a vertical bolted endplate connection and a slant bolted endplate connection due to increase in temperature will be compared
Failure analysis of bolted joints in foam-core sandwich composites
, Article Journal of Reinforced Plastics and Composites ; Volume 27, Issue 15 , 2008 , Pages 1635-1647 ; 07316844 (ISSN) ; Moslemian, R ; Afshin, M ; Nazemi, M. H ; Sharif University of Technology
2008
Abstract
This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed. These solid laminates include a number of glass plies with total thickness equal to core thickness. The effect of solid laminate size and interface angle of foam-solid laminate in the bonding zone on the bearing strength, failure loads and type of modes are investigated. The numerical study is performed using 3D FEM in ANSYS commercial code. Tsai-Wu failure criterion is used in the failure analysis. The...
Progressive bearing failure modeling of composites with double-bolted joints at mesoscale level
, Article Archive of Applied Mechanics ; Vol. 84, issue. 5 , May , 2014 , p. 657-669 ; 09391533 ; Hosseini Kordkheili, S. A ; Toozandehjani, H ; Sharif University of Technology
Abstract
Both numerical and experimental researches are carried out to study the strength of the composite double-bolted joints and the bearing damage propagation. A mesoscale level progressive damage model along with analytical formulation is used to predict the bearing failure of carbon-epoxy composite plates. This damage model is introduced as a user material subroutine in the commercial software ABAQUS, and the maximum failure load is calculated. In order to validate the numerical results, experimental tests are also conducted in which comparison between the results shows an excellent agreement. Furthermore, the effects of the bolt distances on the maximum failure load are studied. The results...
Numerical study of an innovative SMA based beam-column connection in reducing the seismic response of steel MRF structures
, Article Scientia Iranica ; Volume 23, Issue 5 , 2016 , Pages 2033-2043 ; 10263098 (ISSN) ; Yadegari Farzaneh, A ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
During recent years, Shape Memory Alloys (SMAs) have been effectively used to control the seismic response of structural systems. Recovering the residual strains upon unloading (super-elasticity) or by heating (shape memory effect) is the main characteristic of SMA materials. This paper explores the efficiency of a proposed application of steel & SMA bolts in improving the seismic behavior of connections in steel Moment Resisting Frame (MRF) structures. A new semi-rigid, end-plate, beam-column connection is introduced, which is based on parallel application of steel and austenite-phase SMA bolts. A number of 3-D steel MRF structural models with different numbers of stories and mass...
Shear slotted bolted connection
, Article Structural Design of Tall and Special Buildings ; Volume 26, Issue 3 , 2017 ; 15417794 (ISSN) ; Mirghaderi, S. R ; Dolatshahi, K. M ; Sharif University of Technology
Abstract
Slotted bolted connections (SBCs) have been developed and used as an axial friction damper in braced frames since 1980s. To employ the benefits of SBCs in moment resisting frames (MRFs), rotational slotted bolted connections have been developed more recently with limited application in members that flexural behavior is dominated to shear. In this paper, shear slotted bolted connection (SSBC) is introduced as a new type of friction dampers to employ the benefits of SBCs in lateral load resisting systems with predominant shear behavior members that dissipate energy by traditional yielding mechanisms. The SSBC is a modified bolted connection that dissipates energy through friction in which...
Failure analysis of a gas turbine marriage bolt
, Article Journal of Failure Analysis and Prevention ; Volume 7, Issue 2 , 2007 , Pages 81-86 ; 15477029 (ISSN) ; Salimi, H. R ; Sharif University of Technology
2007
Abstract
A gas turbine which output 18MW power exploded after 3h of ordinary operation and after 4,785 starts. The turbine's rotor had undergone repair after 77,000 operating hours. A piece was cut from the failed marriage bolt and tested using atomic absorption spectrometry in order to know the grade of the alloy. It was found that the marriage bolt is made from ASTM A193 B16 steel which is suitable. Hardness and microhardness measurement was also determined and showed that it was within the range of the specified hardness for ASTM A193 B16 steel. The marriage bolt's mechanical properties also meet technical specifications and showed that it contained anti-corrosion properties. Visual examination...
Prediction of the yielding moment of flush endplate splice connections using finite element modeling
, Article Scientia Iranica ; Volume 20, Issue 2 , 2013 , Pages 270-277 ; 10263098 (ISSN) ; Mofid, M ; Sharif University of Technology
2013
Abstract
This paper presents the results of parametric analyses of the yielding moment (My) of Bolted Flush Endplate Beam (BFEB) splice connections using Finite Element Modeling (FEM) tools. The connection components were modeled using three-dimensional brick elements, while contact between the endplates was modeled using Coulomb friction. Materials for beam, endplate and bolts were considered to behave non-linearly. Finite element results with three experimental and numerical studies were compared, and all indicated good agreement, which is also briefly reviewed in this paper. Using verified FEM, fairly large parametric studies, based on the practical configuration of BFEB connections, were carried...
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) ; 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) ; 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...
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) ; 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...
Experimental results and finite-element predictions of the effect of nut geometry, washer and Teflon tape on the fatigue life of bolts
, Article Fatigue and Fracture of Engineering Materials and Structures ; Volume 28, Issue 6 , 2005 , Pages 557-564 ; 8756758X (ISSN) ; Farrahi, G. H ; Hardy, S. J ; Pipelzadeh, M. K ; Habibi, N ; Sharif University of Technology
2005
Abstract
The effect of nut geometry, curved spring washer and a sealing material (Teflon tape) on the fatigue life of M12 and M16 ISO bolts was investigated. This was accompanied by the study of the axial and bending stress distribution in threads by numerical simulation of bolt and nut connections using the finite-element method. The experimental results showed that the highest fatigue life is achieved for a slotted tapered nut. The presence of a spring washer also increases the fatigue life, providing that the correct tightening torque is applied to produce a pretension in the bolt. The use of Teflon tape as a filling material between engaging threads of the bolt and nut is shown to significantly...
A new concept in joining diagonal bracings to horizontal ones
, Article 24th International Conference on Offshore Mechanics and Arctic Engineering, 2005, Halkidiki, 12 June 2005 through 17 June 2005 ; Volume 1 B , 2005 , Pages 699-705 ; England, G. L ; Joeafshan Vishkaie, B ; Sharif University of Technology
2005
Abstract
A new 'universal' structural joint with multiple applications was devised. Its application as a 'beam-to-column joint' was already investigated experimentally, and proven to be promising. The results were reported in previous OMAE conferences and elsewhere. Another fruitful application conceived for this joint is in the context of joining (diagonal) braces to the frame members of a structure. In particular, in chevron (inverted V) bracing systems, where the dominating exchanged forces between the combined diagonal braces and the horizontal brace (beam) are 'shear,' the use of the devised joint as a joining member can substantially improve the overall behaviour of the structure under dynamic...
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) ; 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...
On the assessment of a new steel bolted flush end-plate beam splice connection
, Article Scientia Iranica ; Volume 24, Issue 4 , 2017 , Pages 1735-1750 ; 10263098 (ISSN) ; Mofid, M ; Sharif University of Technology
Abstract
This paper describes the development of a numerical model with the ability to simulate and analyze the mechanical behavior of different types of Double Bolted Flush End-plate Beam (DBFEB) splice connections, which thus far has not been reported. Moreover, Bolted Flush End-plate Beam (BFEB) splice connections have been investigated for calibration of the results using Finite Element Modeling (FEM). The initial stiffness, rotation capacity, strength ratio, ductility, failure mode, and the performance of these two types of connections have been investigated and compared with each other with respect to FEMA 356. Also, classification of these two types of connections is performed by Eurocode 3...
Seismic performance evaluation of a novel bolted flush end-plate beam splice connection
, Article Proceedings of the Institution of Civil Engineers: Structures and Buildings ; Volume 173, Issue 2 , 2020 , Pages 109-127 ; Mofid, M ; Sharif University of Technology
ICE Publishing
2020
Abstract
This paper describes a three-dimensional (3D) finite-element (FE) model developed to assess the seismic behaviour of a novel prefabricated beam-to-beam connection termed a double-bolted flush end-plate beam (DBFEB) splice connection under cyclic loading. The seismic response was analysed and evaluated in terms of the hysteretic behaviour, rigidity, resistance degradation, ductility, energy dissipation capacity and equivalent damping coefficient. It is shown that the required performance can be achieved by controlling the end-plate thickness as well as the bolt grade and diameter; these parameters were therefore chosen as the key geometric variables investigated here for parametric study....