Influence of the P-Delta Effect on the Design of Steel Moment Resisting Frame in Seismic Areas

2021 ◽  
Vol 873 ◽  
pp. 33-37
Author(s):  
Roberto Tartaglia ◽  
Alessia Campiche ◽  
Attilio de Martino
Keyword(s):  
North American ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting Frame ◽  
The North ◽  
Non Linear ◽  
Moment Resisting ◽  
Draft Version ◽  
Steel Moment Resisting Frame ◽  
Lateral Displacements

Steel moment resisting frames (MRFs) compliant with EN1998-1 are generally overdesigned in order to satisfy the requirements for lateral deformability and P-Delta effects. On the contrary, the North American codes (e.g. ASCE7) give different rules for P-Delta effects. The current draft version of the amended EN1998-1-1 introduces a different methodology to account for the structural lateral displacements. In this paper static non-linear analyses were carried out to evaluate the effectiveness of the new EC8 provisions with respect to the former version of EC8 and the current ASCE7. The results show that the structures designed according to the latest draft version of the EN1998-1-1 and those compliant with the North American code exhibit similar behavior.

Evaluation of the seismic level of protection afforded to steel moment resisting frame structures designed for different design philosophies

1999 ◽  
Vol 26 (1) ◽  
pp. 35-54 ◽  
Author(s):  
Aiman Biddah ◽  
Arthur C Heidebrecht
Keyword(s):  
Collapse Mechanism ◽  
Steel Moment Resisting Frames ◽  
Design Philosophy ◽  
Moment Resisting Frame ◽  
Panel Zone ◽  
Statistical Measures ◽  
Frame Buildings ◽  
Moment Resisting ◽  
Steel Moment Resisting Frame ◽  
Recent Earthquakes

Steel moment resisting frames have been considered as excellent systems for resisting seismic loads. However, after recent earthquakes (e.g., Northridge, California, in 1994 and Kobe, Japan, in 1995) the confidence in this structural system was reduced as a result of various types of damage that moment resisting steel frames suffered. This paper presents the results of the evaluation of seismic level of protection afforded to steel moment resisting frame buildings designed in accordance with the National Building Code of Canada. Six- and 10-storey office buildings located in a region of intermediate seismic hazard are designed in accordance with the current Canadian code provisions. Three different design philosophies are considered, namely strong column - weak beam (SCWB), weak column - strong beam (WCSB), and strong column - weak panel zone (SCWP). The performance of these frames is evaluated dynamically by subjecting an inelastic model to an ensemble of 12 actual strong ground motion records. The model takes into account both connection flexibility and panel zone shear deformation. The results are presented in terms of response parameters determined from static pushover analyses, as well as statistical measures of the maximum response parameters determined from the inelastic dynamic analyses. The computed performance of the frames is evaluated in order to assess both the overall level of protection of the frames and the preferred design philosophy. It is concluded that a well-designed and well-detailed ductile moment resisting frame designed using either the SCWB or SCWP design philosophy can withstand ground motions of twice the design level with very little likelihood of collapse, whereas a frame designed using the WCSB approach is ill-conditioned and may develop a collapse mechanism at an excitation level well below twice the design level.Key words: seismic, ductile, steel, frame buildings, performance, design, ductility, damage, inelastic, dynamic.

Computational Approaches for Good Alternative Solutions Based Load Resistance Capacity in Design of Steel Moment-Resisting Frames

2007 ◽  
Vol 347 ◽  
pp. 563-568
Author(s):  
Byoung Han Choi
Keyword(s):  
Optimal Solution ◽  
Load Resistance ◽  
Good Alternative ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting Frame ◽  
Design Alternatives ◽  
Moment Resisting ◽  
Lateral Load Resistance ◽  
Alternative Solutions

A modeling technique to generate good design alternatives from optimal design of steel moment resisting frames is proposed. First presented is the development of Genetic Algorithm(GA)-based approaches that enable designers to identify the best locations for rigid connections in a frame. This GA uses a unique cost function that enables the trade-off study between the number of rigid connections and total cost. Second, the optimization formulation is modified to generate alternatives with a cost comparable to that of the optimal solution. It enables engineers to compare different solutions on the basis of the structure’s lateral load resistance capacity along with incidental factors like the location of the rigid connections, number of different section types, column splices etc. An example of a 5-story and 5-bay steel moment resisting frame is provided to illustrate the effectiveness of the proposed study.

Earthquake resistant design of steel moment resisting frames

1990 ◽  
Vol 17 (4) ◽  
pp. 659-667 ◽  
Author(s):  
R. G. Redwood ◽  
L. Lefki ◽  
G. Amar
Keyword(s):  
Structural Engineering ◽  
Steel Structures ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting Frame ◽  
Earthquake Resistant Design ◽  
Earthquake Resistant ◽  
Moment Resisting ◽  
Engineering Steel ◽  
The Impact

New provisions of the CSA Standard for Steel Structures (CAN/CSA-S16.1-M89) dealing with detailing of moment resisting frames for seismic design are described and related to requirements of the National Building Code of Canada. The basis of the new requirements is outlined, and an example eight-storey frame is used to illustrate the impact of the provisions. Key words: design, structural engineering, steel, earthquakes, moment resisting frame, standards.

scholarly journals A Method to Improve the Seismic Performance of Steel Moment Resisting Frames Based on Eigenfrequency Optimization

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Orlando Arroyo ◽  
Angie V. Osorio ◽  
María Catalina Vargas
Keyword(s):  
Seismic Performance ◽  
Computational Efficiency ◽  
Seismic Fragility ◽  
Engineering Practice ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Building Designs ◽  
Eigenfrequency Optimization

Steel moment resisting frames are a structural system used throughout the world, mainly for their ductility and the speed and ease of their construction. These buildings are usually designed per procedures based on seismic design codes, seeking to minimize the total cost of the building. To aid in better building designs, researchers have proposed different methodologies, which have been proven to be effective. However, their practical use has been limited by their low computational efficiency and their difficulty to implement by practicing engineers. This article proposes a method to improve the seismic performance of steel moment resisting frame buildings based on eigenfrequency optimization. The main advantage of the proposed method is its computational efficiency and that it is simple to implement. The method is demonstrated for a four-story and an eight-story building, whose seismic performance is compared to traditional building designs using nonlinear analyses and seismic fragility functions. The results show that the seismic performance improves significantly with the proposed method with respect to that of traditionally designed buildings, reducing their seismic fragility and increasing their overstrength. These findings and the computational efficiency of the method suggest that it is a viable alternative for use within engineering practice.

Performance-based assessment of seismic-resilient steel moment resisting frames equipped with innovative column base connections

Structures ◽  
2021 ◽  
Vol 32 ◽  
pp. 1646-1664
Author(s):  
Elena Elettore ◽  
Annarosa Lettieri ◽  
Fabio Freddi ◽  
Massimo Latour ◽  
Gianvittorio Rizzano
Keyword(s):  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Performance Based Assessment ◽  
Moment Resisting ◽  
Base Connections ◽  
Column Base
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