Study the Effect of Springboard on Concrete Performance Containing Low-Carbon Steel Spring
ghasem
pachideh
Civil faculty- semnan university
author
majid
Gholhaki
Associate Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran
author
amin
moshtagh
garmsar university
author
text
article
2020
per
One of the most important parameters in spring resistance and strength of concrete containing spring is its step length. In this paper, by adding a low-carbon steel spring with diameter, a number of steps and various mixing rates to self-compacting concrete, attempts have been made to improve its mechanical properties. For this purpose, springs of 8, 12 and 16 mm in diameter, 0.8 mm in thickness, with the number of steps of two, four and six in volumes of volumes of 0.2 and 0.4 in self-supporting concrete were added and compressive strength tests A cylindrical sample measuring 10 x 20 cm), tensile (a cylindrical sample measuring 10 x 20 cm) and a flexural beam (10 x 10 x 50 cm). The results indicate that using a 12 mm diameter spring compressive strength, the tensile and flexural strength of self-compacting concrete increased up to 29, 52 and 36%, but the use of a 16 mm diameter spring did not increase the mechanical properties of self-compacting concrete It also reduces. Due to the high stiffness and positioning of the 8 mm spring diameter within the size of the aggregate, the use of it to improve the mechanical properties of self-compacting concrete requires more research and recognition. Also, the main role in determining the strength of concrete containing springs is played by the diameter of the springs, and the number of step springs will not necessarily be a criterion for determining the increase or decrease of concrete strength. As a general conclusion, it can be argued that the use of six-step springs is not suitable, but the use of two- and four-step springs with regard to the percentage of use and the diameter of the spring used can increase the compressive strength, tensile and flexural strength Give.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
5
23
https://www.jsce.ir/article_81382_852df4de6725ffb38d3c0c2e0ae03cbc.pdf
dx.doi.org/10.22065/jsce.2019.144415.1640
Effect of Stiffeners on Contribution of Peripheral Frame and Seismic Behavior of Stiffened Steel Plate Shear Wall
Parviz
Ebadi
Department of Civil Engineering, Shahr-e-Qods Branch, Islamic Azad University
author
masoud
pishbin
Master of Science in Earthquake Engineering
author
text
article
2020
per
Using Stiffener in steel plate shear wall (SPSW) improves seismic behavior of the system. The transferred force from the steel plate to the peripheral frame is one of challenging topics that discussed by the designers in optimal design of SPSW. Particularly, with the insertion of stiffeners, the amount of transferred force to the columns significantly reduced by the building codes. In this paper, the seismic behavior of a 10-story building with stiffened SPSW investigated in three different design phases. In the first phase, seismic design requirements of American Institute of Steel Construction (AISC) considered with the maximum permissible spacing between the stiffeners. In the second phase, the reductive effects of the building code on transferred forces to the peripheral frame ignored and instead, the minimum required stiffness of peripheral frame considered similar to SPSW without stiffeners. In the third phase, the distance between the stiffeners increased and the optimal design philosophy discussed. In this way, the designer can manage the yielding or buckling of the steel plate. Therefore, the capacity of the floor will be a combination of shear buckling and yield capacity of plate. Plate-Frame Interaction (PFI) theory and finite element tools approved that the peripheral frame design forces and its contribution in seismic behavior of system can vary according to distance of stiffeners.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
24
34
https://www.jsce.ir/article_81404_1c07bea2b500ffe31021cc1b9c5285e6.pdf
dx.doi.org/10.22065/jsce.2019.118861.1461
Influence of nonlinear SSI on the seismic response of low-to-mid-rise steel moment resisting frame buildings
Mohammad
Arbabi
Civil Eng dept., University of Kashan, Iran
author
Hossein
Tahghighi
Civil Eng department, University of Kashan
author
text
article
2020
per
The nonlinear behavior of a soil–foundation interface due to mobilization of the ultimate capacity and the consequent energy dissipation may be utilized to alter seismic demands of a structure. However, current design practice does not account for the nonlinear behavior of soil–foundation interface primarily due to the absence of reliable nonlinear soil–structure interaction (SSI) modeling techniques. The objective of this study is to simulate the performance of multi-story building-foundation systems through a Winkler-based approach. Opensees finite element framework is employed for simulation. Four typical 4, 8, 12 and 16-story steel moment resisting frame (MRF) buildings on three hypothetically soft, medium and hard soil sites with shear wave velocities less than 600m/s subjected to actual ground motion records of varied hazard levels are modeled with and without SSI. It is observed that the performance level of models supported by flexible foundation, particularly in an intense earthquake event, may alter significantly in comparison to fixed-base structures. Moreover, for MRFs on soft soil, the nonlinear foundation is found to have a significant effect on the force and displacement demands. This is indicating the necessity for consideration of flexible foundation behavior in the modern design codes in order to accomplish an economic yet safe structural design.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
35
52
https://www.jsce.ir/article_81405_5886dcbed5b7131cecd4128e95601f7b.pdf
dx.doi.org/10.22065/jsce.2019.142508.1618
Investigation on the effect of the shape, size and location of openings on the seismic behavior of steel plate shear walls connected to frame beams only
Masoud
Pourhasan shahri
Department of Civil Engineering, Quchan University of Technology, Quchan, Iran
author
Ali
Mansouri
Department of Civil Engineering, Quchan University of Technology, Quchan, Iran
author
text
article
2020
per
In the conventional steel plate shear walls (SPSWs), the steel plate is connected to all boundary elements, but in the steel plate shear walls connected to frame beams only (SSW-BOs) the plate is not connected to columns. The separation of the plate from the columns decreases the flexural demands of the columns and prevents the premature failure of the columns. In this paper, the effect of opening properties on the seismic behavior of SSW-BOs is studied through nonlinear finite element modeling and analysis. Based on the obtained results, initial stiffness, lateral strength and dissipated energy were higher in the specimen containing square opening compared to the one with circular opening. Moreover, increasing the opening dimension altered the tension field path from a line along the diagonal of the panel to the corners of the opening and degraded the seismic performance of SSW-BO. The most critical opening location is the central one since it disturbs the lateral load path in the panel more than any other locations. Finally, the results of numerical simulations are used to propose a simple method for estimation of the lateral stiffness and strength of SSW-BOs with openings based on the stiffness and strength reduction factors and the corresponding values of the solid SSW-BOs.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
53
66
https://www.jsce.ir/article_81406_186cbd2487d52c7d32ac1bfd87a4bc82.pdf
dx.doi.org/10.22065/jsce.2019.145514.1653
Investigation into the effect of wind-structure interaction on the along-wind response of tall buildings
behnam
shirkhanghah
ph D. student, Department of civil engineering, University of Mohaghegh Ardabili, Ardabil, Iran
author
Houshyar
Eimani kalehsar
Assistant professor, Department of Civil Engineering, University of Mohaghegh Ardabili, Ardabil, Iran
author
text
article
2020
per
Rapid growing of population, limitation of space, economic and social parameters are reasons that have led to the construction of tall buildings. On the other hand, due to invention of strong and lightweight materials, tall buildings had low damping ratio and long vibrational periods. For this reasons, it is necessary to investigate and analyze tall buildings under wind loads. In the present research, wind-structure interaction is performed on standard tall building CAARC using computational fluid dynamics (CFD), computational structural dynamics (CSD) and ABAQUS finite element software. The wind mean velocity profile is modelled using exponential formula in the boundary layer of atmosphere, wind turbulence is simulated using implicit large eddy simulation method (ILES), and co-simulation method is used to transfer non-uniform loads from fluid domain to structural nodes. Structural damping is determined by Rayleigh method. To validate the modelling, results are compared with reliable numerical and experimental findings. Results show that non-damped structures have responses significantly higher than damped structures. It is concluded that the distribution of the average wind pressure in high-rise buildings is influenced by the average wind speed. Therefore, in order to assurance in the design of tall structures, mechanical properties of wind and structure must be considered.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
67
86
https://www.jsce.ir/article_81407_3e8f8bf4f6e959a2a484c4afb07c97a6.pdf
dx.doi.org/10.22065/jsce.2019.148599.1662
Optimization of time, cost and quality in critical chain method in multi project scheduling and resource constraints with considering utility function
Mohammad Javad
Taheri Amiri
PhD in construction engineering and management, Babol University of Technology, Babol, Iran
author
farshidreza
haghighi
Assistant Professor, faculty of civil engineering, Babol University of technology
author
Ehsan
Eshtehardian
Assistant professor, Tarbiat Modares University
author
Milad
Hemmatian
PhD student, Industrial Engineering, Mazandaran University of Science and Technology, Babol, Iran
author
Roham
khaleghnejad
MSc in construction engineering and management, Tabari University of Babol
author
text
article
2020
per
Considering that the mission of the project organization management is to create a commitment to the timetable, which prevents project delays and increases associated costs, and accept the fact that the delay in the completion time of the project results in the non-economization of the project, Therefore, the necessity of using proper planning and control methods seems necessary. One of the new methods used in project planning and control, which today focuses on many researchers, is the critical chain management method. In this research, multi-project scheduling with resource constraint in the critical-chain model has been investigated. In general, RCMPSP seeks to find the right sequence for project activities, so that the constraints of the priority of the project network and the various types of resource constraints in the project are met simultaneously. To this end, a multi-objective optimization model has been developed to solve this problem, with its stated objectives, the completion time of the entire project, the cost of the overall project implementation, and the quality of the implementation of the project activities. Also, the critical chain approach, as a new method of project management, has been used for project scheduling and particle swarm optimization algorithm for solving proposed model of this research.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
87
108
https://www.jsce.ir/article_81545_5dc8245a124f8a33230075b60e710a7d.pdf
dx.doi.org/10.22065/jsce.2019.122218.1496
Obstacles to Public and Nongovernmental Collaboration in BOT Freeway Projects in Iran
yousef
Shahbazi Razlighi
Project & Construction Management Department, Art Faculty, Tarbiat Modares University, Tehran, Iran
author
mohammad hossein
sobhiyah
Project management and construction department, Art faculty, TMU university,
author
Hasan
Danaeefard
Professor of Public Administration Department, Management and Economics Faculty, Tarbiat Modares university, Tehran, Iran
author
text
article
2020
per
The present study aims at presenting the pathological model of the process of collaboration between the public and nongovernmental sectors as one of the key factors affecting project performance utilizing multi-case research method as well as the grounded theory for data analysis. This research tries to find quality partnerships for implementing projects that are delivered by BOT. These drivers will include the causal conditions, structures, processes, and mechanisms of actors involved in public-private partnerships. In this regard, at first step, by reviewing the literature, the approach of developed and developing countries, and the way, in which, the parties engage in different contexts are investigated.Then, the required data is collected to be used in the grounded theory by referring to the successful and unsuccessful cases in collaboration between the governmental and nongovernmental sections, and conducting interviews with different individuals from different levels of management from both sectors, attending meetings of the committee of investment companies in the construction of Iranian freeways and memorization from our observations of how the dialogue, behavior and interaction of the parties. Then, by analyzing the acquired data, the Pathology Model of the collaborative process between public sector and non-governmental sector in BOT freeway projects is developed.According the obtained results in this study, the lack of respect, risk coverage, and joint decision making constitute the phenomenon of undesirable partnership. Finally, while comparing this research findings with those existing in the literature, executive suggestions are made to reduce challenges and promote existing collaborative efforts.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
109
129
https://www.jsce.ir/article_81546_cda07ebfcd59901df151dfd29db6e4a9.pdf
dx.doi.org/10.22065/jsce.2019.134930.1589
Selection of an appropriate ground motion records set for time history analysis using uniform hazard spectrum
Aliakbar
Yahyaabadi
Department of Civil Engineering, Faculty of Engineering, University of Bojnord, Bojnord, Iran
author
Nasrin
Nomani
Department of Civil Engineering, Faculty of Engineering, University of Bojnord, Bojnord, Iran
author
text
article
2020
per
In time history analysis of structures, it is essential to select an appropriate set of earthquake ground motions using the meaningful statistical methods. This matter is a challenge in earthquake engineering because the characteristics of future earthquakes are unpredictable. In this paper, earthquake ground motion records were selected based on the geological and geotechnical characteristics of the desired site. The record sets proposed here can be used for analyzing any structure with a desired fundamental period, even for sites that have potential to experience near-fault pulse-like events. The records were selected based on the response spectra simulated according to the statistical characteristics of the target Uniform Hazard Spectrum (UHS). The objective is that the response spectra of the selected records have the mean and standard deviation that are consistent with the corresponding values of the target UHS. In addition to the mean, the standard deviation was also considered in the records selection procedure to capture the ground motion aleatory uncertainty. Two appropriate sets of 7 and 30 records, selected from about 300 earthquake ground motion records, were suggested for each soil types of I, II, and III. Additionally, an efficient method referred to as the least sum of squared errors was developed for scaling the records with respect to the standard No. 2800 of Iran. Results demonstrate that using the different methods for scaling the records leads to various scaling factors for records, and as a consequence different structural responses using the method of time history analysis.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
130
144
https://www.jsce.ir/article_81547_f7c6b67c8446c8de56b23a44e3c65ef2.pdf
dx.doi.org/10.22065/jsce.2019.143503.1625
Optimization of nonlinear viscous damper characteristics to reduce the response of concrete structures with linear and nonlinear behaviours
Reza
Kamgar
Department of Civil Engineering, Shahrekord University, Shahrekord, Iran
author
Mohammad Reza
Babadaei Samani
Master of Science of Civil Engineering, Technology Unit of Arian Saze Zagros, Chaharmahal Science and Technology Park, Shahrekord, Iran
author
Heisam
Heidarzadeh
Department of Civil Engineering, Shahrekord University, Shahrekord, Iran
author
text
article
2020
per
Nowadays, controlling vibration of a structure in earthquakes and reducing the structural responses are of great importance. Dampers are a type of systems controlling the absorption of the earthquake energy and dissipating it in order to reduce the structural responses. The main objective of this paper is to find the optimal characteristics of the nonlinear viscose dampers placed at all storeys in a three-storey single bay concrete frame. It is assumed that the structure is subjected to the Elcentro and Gazli earthquakes; and both linear and nonlinear behaviors are considered for the structure during the earthquakes. OpenSees software is used to model the concrete frame and nonlinear viscous dampers. The structural responses are calculated at different time steps, using Newmark's numerical method. A series of constraints which are considered during the optimization process include the limits for parameters of nonlinear viscous damper (Viscous coefficient, axial stiffness and damper exponent) and the maximum absolute value for base shear. The objective is to find optimal values for these parameters in such a way that the maximum absolute value would be minimized for the roof displacement during the earthquake load. The results show that the nonlinear viscous damper is very suitable to control the structure responses when it has linear behavior. In fact, when the structure is subjected to the Elcentro earthquake, the maximum absolute value of the roof displacement and base shear decrease by 37.51% and 43.39%, respectively. The nonlinear behavior of the concrete frame does not improved considerably when the nonlinear viscous dampers are used to control the nonlinear response of the structure in the earthquake.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
145
166
https://www.jsce.ir/article_81548_78888d20930e3857511a95eff9b84663.pdf
dx.doi.org/10.22065/jsce.2019.148073.1659
The behavior of horizontally bent buried pipes along faults slip with numerical and experimental modelling
masoud
nekooei
Earthquake and Structure Engineering Department, Science and Research Branch, Islamic Azad university, Tehran, Iran
author
Sahand
Sarioletlagh Fard
Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
author
Asghar
VataniOskouei
Department of Civil Engineering, ShahidRajaee Teacher Training University, Tehran, Iran
author
Armin
Azimi Nejad
Earthquake and Structure Engineering Department
author
text
article
2020
per
Considering the high importance of energy-carrying buried pipelines in lifeline network, it is vital to understand this kind of structures against seismic dynamic excitations.In this paper, seismic behavior in some part of a buried pipe with horizontal bend under Bam earthquake record effect (2003, Iran) is studied experimentally and numerically using ABAQUS software. In the numerical model, the pipe is modelled via a three-dimensional four-node shell system, and the soil is modeled using elastoplastic properties.As non-linear dynamic analysis, with applying Bam earthquake record effects, a thorough parametric studied are performed on different pipe diameter and thicknesses, and then the axial strain and plastic strain values obtained from the strain gauges along the horizontally-bent pipe are compared with the numerical model results.Also, a correlation is obtained which relates the location of plastic hinge formation point on the pipe to the pipe diameter and thickness. The comparison of numerical model and experimental results show that in buried horizontally-bent pipes, the most axial strain, plastic strain, and stress in the pipe take place in the fixed wedge and near to the fault line. In the buried horizontally-bent pipes, with increasing the pipe diameter to thickness ratio this location will get more distance from the fault line.Also, the pipelines with larger diameters have lower pipe-soil strain ratio (εp/s) values causing lower axial and plastic strains.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
167
184
https://www.jsce.ir/article_81569_dc09da15e852b03baa987e7adb32bd52.pdf
dx.doi.org/10.22065/jsce.2019.148084.1657
Elastic instability and free vibration analyses of axially functionally graded Timoshenko beams with variable cross-section
Masoumeh
Soltani
Department of civil engineering, Faculty of engineering, University of Kashan, Kashan, Iran
author
Behrouz
Asgarian
Faculty of civil engineering, K.N. Toosi University of Technology, Tehran, Iran
author
Vahid
jafari Deligani
Department of civil engineering, Faculty of engineering, University of Kashan, Kashan, Iran
author
text
article
2020
per
In this paper, the critical buckling loads and natural frequencies of axially functionally graded non-prismatic Timoshenko beam with different boundary conditions are acquired using the Finite Difference Method (FDM). In the recent years, the use of functionally graded materials (FGMs) has been increasing in different mechanical components due to their conspicuous characteristics such as high strength, thermal resistance and optimal distribution of weight. The designer can thus produce structures with favorable stability and manage the distribution of material properties. In this study, the material properties of non-prismatic Timoshenko beams such as Young’s modulus of elasticity and density of material are described by a power-law formulation along the beam axis. Contemplating elastic behavior, the system of equilibrium equations of non-uniform Timoshenko beam and the related boundary conditions are coupled in terms of the vertical displacement and the bending rotation of the cross-section. Afterwards, the system of second-order differential equations with variable coefficients and end conditions are discretized by finite difference formulations with second-order accuracy. Finally, the system of finite difference equations culminates in a set of simultaneous and linear equations and the critical buckling loads and natural frequencies are calculated by solving an eigenvalue problem of the obtained algebraic system. In order to demonstrate the accuracy and reliability of this approach to calculate elastic buckling loads and natural frequencies of functionally graded (FG) Timoshenko beams, one comprehensive example including axially non-homogeneous and homogeneous members with non-uniform cross-section is expressed. The numerical results in clamped-clamped, simply supported and fixed-free boundary conditions are accomplished. Moreover, the effect of various parameters such as volume fraction index, end conditions and the section variation on the elastic buckling and free vibration behavior of AFG Timoshenko beam are investigated in detail.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
185
202
https://www.jsce.ir/article_81588_cf6f63a0f3bf7c15b19f6376d893aefe.pdf
dx.doi.org/10.22065/jsce.2019.143692.1627
Experimental study on shear strengthening of steel beams using CFRP strips
Kambiz
Narmashiri
Assistant Professor of Structural Engineering, Department of Civil Engineering, Faculty of Engineering, Zahedan Branch, Islamic Azad University, Zahedan, Iran
author
Mahbobeh
Joshang Rigi
Department of Civil Engineering, Zahedan Branch, Zahedan, Iran
author
text
article
2020
per
Steel structures are one of the most used type of structures. Some of the steel structures may need to be strengthened due to different reasons. There are different methods for strengthening of this kind of structures. In recent years, strengthening of steel structures using Fiber Reinforced Polymers (FRP) has been most interested. This study investigates the shear strengthening of steel beams using one and both sides strengthening of the web by different angles of Carbon Fiber Reinforced Polymers (CFRP) strips. Five specimens were investigated in laboratory experimentally. The test method was four-point bending approach. The load was applied on a connector loading beam by a hydraulic jack, then the load was applied on the main beam through two equal point loads. The beams had two simple supports at the both ends. The loading type was the static gradual loading type. The dimensions of the beams were chosen in the way that beams behave most in shear. This means that beams fail first due to shear stress. One beam was not strengthened, and two beams were strengthened using vertical strips on one or both sides of the web, and two remained beams were upgraded using diagonal strips. Results of this research indicates efficiency of CFRP strips for increasing load-bearing capacity of the beams. Strengthening using diagonal strips on both sides of the web demonstrated the most increment in load-bearing capacity.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
203
217
https://www.jsce.ir/article_81704_c3cf22b05c0e04e33248d1e4fc40496f.pdf
dx.doi.org/10.22065/jsce.2019.136105.1592
Investigation of the effect of thickness and type of steel on the behavior of steel plate shear wall under blast loads
Hossein
Khorshidi Mianaei
M.Sc in Structural Engineering, Department of Civil Engineering, K.N.Toosi University of Technology, Tehran, Iran
author
Masoud
Mirtaheri
Associate Professor, Department of Civil Engineering, K.N. Toosi University of Technology,Tehran, Iran
author
Hamidreza
Rezaei Barounaghi
Reasercher, Center of Safe Structures and Materials, Malek Ashtar University of Technology, Tehran,Iran
author
text
article
2020
per
One of the aims of passive defense, is designing of safe structures against explosion. Nowadays, with expansion of bombing attacks into the building, it is necessary to investigate the behavior of structures under blast loads. In recent years, Steel plate shear walls (SPSWs) have become an increasingly popular lateral force resisting system in building. Low cost, quick installation and high energy absorption potential, has made SPSWs as a suitable system for strengthening existing structures. Considering the prominent features of easy going steel plate wall against lateral loads, such as high energy absorption, good ductility and hardness increasing and displacement reduction, study the behavior of this system against blast loads is necessary. Therefore, in this paper by modeling of SPSW specimen in the finite element software ABAQUS , verification of modeling and software work, were examined as compared to the experimental data. Then structural steel plate shear wall and Easy going steel plate shear wall by AISC 20 Design Guide were designed, and both systems, with thicknesses of 1, 1.5, 2 and 2.5 times the designed plate thickness were investigated under the near and far field explosions. Results of these analyses showed using Easy going steel plate in shear wall systems caused reduction of steel frame displacement. Also by Increasing the plate thickness of both Easy going steel and structural steel systems, under the near and far field explosions, displacement decreased.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
218
238
https://www.jsce.ir/article_81768_2be4582e920eec07854955d8d2c39882.pdf
dx.doi.org/10.22065/jsce.2019.144313.1637
Nonlinear stability analysis of non-prismatic simple steel frames with flexible supports and semi-rigid connection
mohsen
bambaeechee
Dept. of Civil Engineering,
Faculty of Engineering,
Quchan University of Technology,
Quchan, Iran.
author
ghasem
Paseban
M. Sc. Student of Structural Eng., Faculty of Civil Eng., Quchan University of Technology, Quchan, Iran
author
text
article
2020
per
In this paper, various methods of linear and nonlinear stability analysis of simple steel frames are introduced. In the following, based on moderately large rotations and small strains, nonlinear stability analysis of a non-prismatic simple steel frame with semi-rigid connection and flexible supports is performed, which is subjected to a concentrated vertical load eccentrically at its joint. Accordingly, firstly, the accuracy and capability of suggested formulations will be verified by comparing with the results of other researchers. Then, the effects of eccentric axial load factor, shape factor of non-prismatic column, rotational stiffness of elastic support, translational stiffness of lateral support, rotational stiffness of beam-column connection and slenderness ratio of members on the pre-bucking and post-buckling behavior of a steel frame will be investigated. The results show each of these factors has a significant effect on the equilibrium path and buckling load of the structure. In other words, by increasing the slenderness ratio of members, shape factor and stiffness of connections, increases the nonlinear buckling load of the structure. Accordingly, the translational stiffness of lateral support and slenderness ratio of members have the maximum and minimum effect on this increase, respectively. Moreover, by utilizing the non-linear stability analysis, the buckling load of the simple steel frame reduces with respect to linear stability analysis.
Journal of Structural and Construction Engineering
Iranian Society of Structural Engineering (ISSE)
2476-3977
7
v.
شماره ویژه 3
no.
2020
239
258
https://www.jsce.ir/article_81769_362aac311a80b25f0255a1e76de62bc8.pdf
dx.doi.org/10.22065/jsce.2019.144522.1641