A Computer Programme for the Analysis and Design of Steel Structures

Author(s):  
A.V. Avdelas ◽  
P. Stavridis
2005 ◽  
Vol 8 (3) ◽  
pp. 231-245 ◽  
Author(s):  
K. F. Chung

This paper presents a number of experimental and theoretical investigations into the structural behaviour of cold-formed steel structures with bolted connections. Firstly, the basic deformation characteristics of bolted fastenings between cold-formed steel strips in lap shear tests is described, and advanced finite element modelling with solid elements as well as contact elements is carried out for comparison. Secondly, the structural behaviour of lapped Z sections with bolted moment connections is reported, and both analytical and numerical predictions on strength and stiffness of lapped Z sections are presented. Finally, the structural performance of double span lapped Z purlins is investigated numerically where the effects of lapped Z sections over internal supports on the internal force distributions along the purlin members are examined. The description is intended to provide both analysis and design methods as well as understandings to structural engineers, enabling them to design and build cold-formed steel structures rationally with improved structural performance.


1999 ◽  
Vol 26 (2) ◽  
pp. 156-167 ◽  
Author(s):  
D I Nwosu ◽  
VKR Kodur

A state-of-the-art review of the behaviour of steel frame structures in fire is presented. Results from different studies indicate that the behaviour of a complete structure is different from that of a single structural member under fire conditions from the point of view of fire resistance. Earlier studies also show that analysis and design of steel structures against fire based on their overall behaviour could lead to a reduction or the elimination of applied fire protection to certain structural members. The effects of continuity, restraint conditions, and load ratio on the fire resistance of frame structures are discussed. The beneficial aspects derived from considering overall structural rather than single-member behaviour in fire are illustrated through the analysis on two one-bay, one-storey, unprotected steel portal frames, a column, and a beam. Also comparison is made between the performance of a beam with different end restraints in fire. Results from the analyses indicate that the fire resistance of a member is increased when it is considered as part of a structure compared with when it is considered as a single member.Key words: steel, frames, fire resistance, buckling, loads, overall structural behaviour.


2002 ◽  
Vol 5 (2) ◽  
pp. 75-85 ◽  
Author(s):  
G. N. Ronghe ◽  
L. M. Gupta

The concept of prestressing steel structures has only recently been widely considered, despite a long and successful history of prestressing concrete members. Several analytical studies of prestressed steel plate girder were reported in the literature, but much of that work was not studied with reference to different parameters like tendon profile, eccentricity, partial span to full span ratio, prestressing force, load carrying capacity etc. associated with prestressing. This paper examines analytically a comparative study of various tendon configurations and prestressing parameters on over all analysis and design of prestressed steel plate girder. The output from the computer Program for analysis and design of steel plate girder prestressed with different tendon configurations are compared among each other. As a Case-study, a prototype model of Prestressed Steel Testing Frame with straight tendon has been designed, constructed and tested in the laboratory for its safe load carrying capacity and maximum deflection.


2011 ◽  
Vol 378-379 ◽  
pp. 775-779
Author(s):  
M. Mirtahery ◽  
Zoghi M. Abbasi

Since Ronan Point tower local collapse in UK in 1968, progressive collapse phenomenon in structures attracted more attention for civil engineers all over the world so there were no useful researches and manual codes related to progressive collapse designing before. Progressive collapse occurs when loading pattern, boundary condition and resisting path changed, so critical elements undergo excessive unpredicted loading. We cannot omit reason of collapse as well as prevention of distribution of it that cause progressive collapse. Also, we cannot predict exact location of collapse beginning, so we should generalized design guides to whole or part of structures elements based on risk analyzing. Also we can use load carrying element removal scenario for critical elements. To prevent progressive collapse, structural systems require to having a well-distributed, redundant lateral load resisting system and ductile connections capable of undergoing large inelastic rotations without failing. There are some new guides and criteria for elements and connections to be designed to resist progressive collapse. Depends on required accuracy, importance of the buildings and acceptable risk level, the analysis methodologies ranged from linear to nonlinear with static and dynamic approaches. In this paper, codes and researches recommendations to resist progressive collapse for steel structures are presented, classified and compared. Also, applicable design methods based on codes and some retrofitting methods are summarized.


2016 ◽  
Vol 10 (1) ◽  
pp. 677-684
Author(s):  
Mehdi Babaei ◽  
Jalal Dadash Amiri ◽  
Foad Omidi ◽  
Arman Memarian

Today, steel structures with simple frames and concentric steel bracings (both crossed and chevron type) are extensively used in different countries, as well as in Iran. Apart from the seismic performance of each structural system, construction cost plays a significant role in system selection by designers. In an attempt to optimize structural costs, this study aims at examining the number of floors, span length, soil conditions, and brace type. In this study the impact of these factors on structural costs are evaluated. Since parking areas are the most important architectural requirement, therefore specified span widths accommodating two, three, and four vehicles are selected for the models. To this end, regular building models with different span (5.6, 7.5, and 11.2m) are selected according to such architectural considerations. Following structural analysis and design, total structural costs are estimated according to the latest national cost list issued by the Management and Planning Organization of Iran (published in 2014). The results are obtained and reported for different models through graphs and tables. The outcomes are evaluated and compared. Finally, the optimal topologies in terms of structure weight and total cost are determined, along with introducing the most effective factor among span length, story number, brace type, and soil type.


In the present study four G+5 steel structures were modeled without bracings and having X, V bracings and diagonal bracings with foundation depth of 2m support conditions are assumed to be pinned at the bottom or at the supports/footings, seismic loads are applied as per IS:1893-2002 The structures having length = 28.2 m, width = 17m and height = 20m. The structures modeled in STAAD.Pro“structural analysis and design software by considering various loads and load combinations by their relative occurrence are considered the material properties considered are” Fe250 rolled steel sections structures were considered in seismic zones 2, 3, 4 and 5 X type bracings systems are observed to better in high seismic zones.


2021 ◽  
Vol 0 (15) ◽  
pp. 0-0
Author(s):  
Fahım Ahmad NOWBAHARI ◽  
Elif AĞCAKOCA

Earthquake loads are the biggest obstacle to the design of multi-storey and irregular structures in countries located in the earthquake zone and with active earthquake faults. It is a dangerous natural disaster that can result in loss of life and property depending on the intensity of the earthquake. It is important to use comprehensive and up-to-date standards and regulations for the calculation of earthquake loads. In this study, considering TBDY-2018, dynamic behavior of multi-storey steel structure with irregularity called A1 Torsional Irregularity has been investigated. For seismic load calculations, mode combination method and equivalent earthquake load method, which are linear analysis methods, were used. In a 10-storey steel structure, central inverted V braces were used and the positions of these braces were changed and a total of 4 models were produced. Structural analyzes were made using the "Etabs" program. Then, the results obtained in the two methods used were compared, and in the structural analysis of the models used, it was seen that the internal forces and displacements gave greater results when the calculations were made with the Equivalent Earthquake Load Method. In addition, it has been stated that the torsional irregularity coefficient of the structure is effective in the horizontal displacement of the structure.


2021 ◽  
Vol 0 (15) ◽  
pp. 0-0
Author(s):  
Fahım Ahmad NOWBAHARI ◽  
Elif AĞCAKOCA

When observing the consequences of earthquakes, it is accepted that earthquakes are one of the most dangerous natural disasters in the world. Therefore, special engineering methods are used to explore and analyze the effects of earthquakes on structures and to design earthquake resistant structures accordingly. In applying these methods, it is important to investigate the irregularities in the carrier system correctly. There are six irregularities in the Turkish Building Earthquake Code (TBDY-2018), one of the most important of which is A1 Torsional Irregularity [TBDY 2018]. In this article, considering TBDY 2018, the dynamic behaviour of structures with different ratios of torsional irregularity in multi-storey steel structures is examined. In a 10-storey steel structure with the same purpose and size, four type models were produced using the central inverted V cross member and changing the cross positions. The Equivalent Seismic Load Method is used in the analysis. Structural analyzes were performed with the "ETABS" finite element program. As a result of these studies; The displacements obtained from the structural analysis of 4 models with different torsional irregularity coefficients due to the cross member placement in various places in 4 buildings with the same dimensions were calculated by the Equivalent Seismic Load method.


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