Modal strength reduction factors for seismic design of plane steel frames

2011 ◽  
Vol 2 (1) ◽  
pp. 65-88 ◽  
Author(s):  
George A. Papagiannopoulos ◽  
Dimitri E. Beskos
Keyword(s):  
Seismic Design ◽  
Steel Frames ◽  
Strength Reduction ◽  
Reduction Factors

scholarly journals Ductility and Strength Reduction Factors for Degrading Structures Considering Cumulative Damage

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Edén Bojórquez ◽  
Sonia E. Ruiz ◽  
Alfredo Reyes-Salazar ◽  
Juan Bojórquez
Keyword(s):  
Structural Properties ◽  
Seismic Design ◽  
Ground Motions ◽  
Strength Reduction ◽  
Cumulative Damage ◽  
Earthquake Resistant ◽  
Earthquake Resistant Structures ◽  
Simple Systems ◽  
Insight Into ◽  
Reduction Factors

The effect of cumulative damage on the strength requirements of degrading structures is assessed through the evaluation of the target ductility and corresponding strength reduction factors of simple degrading structures. While the reduction on ductility is established through the use of Park and Ang index, the suggestions given by Bojórquez and Rivera are used to model the degradation of the structural properties of the simple systems. Target ductilities and their corresponding reduced strength reduction factors are established for five sets of ground motions; most of them are recorded in California. The results given in this paper provide insight into all relevant parameters that should be considered during seismic design of earthquake-resistant structures. Finally, some recommendations to evaluate the effect of cumulative damage on seismic design are suggested.

Modal strength reduction factors for seismic design of plane steel braced frames

2018 ◽  
Vol 147 ◽  
pp. 549-563 ◽  
Author(s):  
Nicos A. Kalapodis ◽  
George A. Papagiannopoulos ◽  
Dimitri E. Beskos
Keyword(s):  
Seismic Design ◽  
Strength Reduction ◽  
Braced Frames ◽  
Reduction Factors

Demand Diagrams Based on Inelastic Spectra: A Proposal for the Implementation of the Capacity Spectrum Method in the Romanian Seismic Design Code

2014 ◽  
Vol 580-583 ◽  
pp. 1600-1603 ◽  
Author(s):  
Iolanda Gabriela Craifaleanu
Keyword(s):  
Seismic Design ◽  
Strength Reduction ◽  
Capital City ◽  
Design Code ◽  
Capacity Spectrum Method ◽  
Spectrum Method ◽  
Capacity Spectrum ◽  
Seismic Design Code ◽  
Starting Point ◽  
Reduction Factors

During recent years, an increasing number of studies advocate the application of the capacity spectrum method based demand diagrams computed directly from inelastic response spectra, as an alternative to the basic formulation of the method, which uses elastic spectra computed for single degree-of-freedom oscillators with modified characteristics to account for inelastic behavior. When demand diagrams are based on the code-specified elastic spectrum, inelastic spectra are typically determined by dividing the elastic spectrum by strength reduction factors. The paper presents the application of the method, based on strength reduction factors computed with a unified analytical expression, deduced by the author in previous studies. The expression and is valid both for broadband and narrow band ground motions. Taking as a starting point the newly-enforced elastic design spectra in the 2013 edition of the Romanian seismic design code, the method is exemplified for the capital city, Bucharest. It is shown that, for the analyzed case, the use of the proposed strength reduction factors leads to results that are very close to those obtained by the “classical” nonlinear static procedure used in the code. This suggests a good potential for the implementation of the capacity spectrum method in the Romanian code, based on these factors.

Experimental Study on Steel Frames Infilled with Sandwich Composite Panels

2011 ◽  
Vol 243-249 ◽  
pp. 499-505
Author(s):  
Can Xing Qiu ◽  
He Tao Hou ◽  
Wei Long Liu ◽  
Ming Lei Wu
Keyword(s):  
Seismic Design ◽  
Steel Frames ◽  
Strength Degradation ◽  
Hysteretic Behavior ◽  
Sandwich Composite ◽  
Viscous Damping ◽  
Test Results ◽  
Ductility Index ◽  
Damage Process ◽  
Seismic Behaviors

A model of full scale one-bay, one storey was tested under low cyclic loading in order to study the hysteretic behavior of steel frames with sandwich composite (SC) panels. According to the failure pattern and damage process of test specimen, seismic behaviors were evaluated. Hysterics loops, skeleton curves, curves of strength degradation, and curves of stiffness degradation, ductility index and viscous damping coefficient were analyzed. Test results show that the failures of panels mainly occurred around the embedded parts, but compared with traditional panels and walls, SC panels exhibit a better integration. The connection between panel and steel frame is vital to the mutual work of the two parts. Finally, seismic design recommendations based on the analysis of ductility index and energy dissipation of the structures are presented.

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