scholarly journals The energy dissipation effects of redundant members in silos under earthquakes

1987 ◽  
Vol 20 (4) ◽  
pp. 269-274
Author(s):  
Zhiming Li ◽  
Shujiang Geng
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Structural Model ◽  
Structural Parameters ◽  
Lateral Force ◽  
Strong Base ◽  
History Analysis ◽  
Response History Analysis ◽  
Application Potential ◽  
Internal Forces

An analytical study is made of the response to strong base motion of reinforced concrete silo structures having energy dissipation redundant members. The structural model consists of an axisymmetric silo body supported by reinforced concrete columns. Analytical methods used include inelastic dynamic response history analysis, inelastic static analysis, and elastic modal spectral analysis (Building Code of China). The sensitivity of the structural parameters, such as the location of redundant members, relative linear stiffness, and reinforcement ratios, are examined for lateral force and ground motions. Based on the data presented, it is concluded that the advantages of energy dissipation redundant members are of ensuring yielding hinges occur in selected elements, improving the distribution of internal forces, and providing increased ductility. Numerical examples are discussed to show the application potential.

Developing a simplified method for analysis and design of isolated structures with the novel quintuple friction pendulum system under bidirectional near-field excitations

2021 ◽  
pp. 107754632110482
Author(s):  
Hamed Keikha ◽  
Gholamreza Ghodrati Amiri
Keyword(s):  
Nonlinear Response ◽  
Near Field ◽  
Lateral Force ◽  
History Analysis ◽  
Special Cases ◽  
Simplified Method ◽  
Response History Analysis ◽  
Nonlinear Response History Analysis ◽  
Isolated Structures ◽  
Friction Pendulum

Simplified analysis methods for seismically isolated structures proposed in recent structural codes and specifications are frequently used to reduce the computational effort and to simplify the design procedure, either directly for special cases or for checking the results of nonlinear response history analysis. Of the approximate methods, the equivalent lateral force procedure using the effective stiffness and effective damping is one of the best known. In this study, the simplified method is developed by combining the equivalent lateral force procedure with the capacity spectrum method and evaluated in terms of maximum isolator displacements and base shears for isolated structures with recently invented quintuple friction pendulum isolators , with different geometrical and frictional properties, under two different response spectra with corresponding two different sets of bidirectional near-field ground motions for stiff and soft soils site classes. In order to assess the accuracy of the simplified method, the delivered results of the ELF procedure are compared to those of nonlinear response history analysis, by modelling the quintuple friction pendulum isolator 3D element in OpenSees. Eventually, comments on the accuracy of the simplified method are given to make its applications more appropriate in practical design of base isolation systems.

Response History Analysis for the Design of New Buildings in the NEHRP Provisions and ASCE/SEI 7 Standard: Part I - Overview and Specification of Ground Motions

2017 ◽  
Vol 33 (2) ◽  
pp. 373-395 ◽  
Author(s):  
Curt B. Haselton ◽  
Jack W. Baker ◽  
Jonathan P. Stewart ◽  
Andrew S. Whittaker ◽  
Nicolas Luco ◽  
...  
Keyword(s):  
Structural Model ◽  
Ground Motions ◽  
Uniform Hazard Spectra ◽  
Collapse Probability ◽  
History Analysis ◽  
Critical Issues ◽  
Random Components ◽  
Response History Analysis ◽  
Definition Of ◽  
New Buildings

This manuscript, the first in a four-part series, describes the response history analysis approach developed for Chapter 16 of the ASCE/SEI 7 Standard and critical issues related to the specification of ground motions. Our approach provides new procedures for demonstrating adherence to collapse safety goals for new buildings (≤10% collapse probability at the MCER shaking level), creating nonlinear structural models, selecting and applying ground motions to the structural model, interpreting computed structural responses, and enforcing acceptance criteria to achieve the collapse safety goal. The ground motion provisions provide the option of using target spectra having more realistic spectral shapes than traditional uniform hazard spectra. Ground motions are developed using a two-stage procedure emphasizing spectral shape in their selection, followed by scaling or matching them to the target, with a modest penalty for matching. Horizontal component motions are applied to the structural model with random components to avoid bias associated with the maximum-component definition of the target spectrum.

scholarly journals Orientation effects of horizontal seismic components on longitudinal reinforcement in R/C frame elements

2012 ◽  
Vol 12 (1) ◽  
pp. 1-10 ◽  
Author(s):  
K. G. Kostinakis ◽  
A. M. Athanatopoulou ◽  
I. E. Avramidis
Keyword(s):  
Ground Motion ◽  
Cross Sections ◽  
Linear Response ◽  
Ground Motions ◽  
Longitudinal Reinforcement ◽  
Analysis And Design ◽  
History Analysis ◽  
Response History Analysis ◽  
Internal Forces ◽  
Horizontal Ground Motion

Abstract. The present paper investigates the influence of the orientation of recorded horizontal ground motion components on the longitudinal reinforcement of R/C frame elements within the context of linear response history analysis. For this purpose, three single-story buildings are analyzed and designed for 13 recorded bi-directional ground motions applied along the horizontal structural axes. The analysis and design is performed for several orientations of the recording angle of the horizontal seismic components. For each orientation the longitudinal reinforcement at all critical cross sections is calculated using four methods of selecting the set of internal forces needed to compute the required reinforcement. The results show that the reinforcement calculated by three of the applied methods is significantly affected by the orientation of the recording angle of ground motion, while the fourth one leads to results which are independent of the orientation of the recording angle.

scholarly journals Displacement-based design of Reinforced Concrete Special Moment Frame (RC-SMF) with Vertical Irregularity

2019 ◽  
Vol 258 ◽  
pp. 05014
Author(s):  
A F M Salman Akhter ◽  
Yoyong Arfiadi
Keyword(s):  
Reinforced Concrete ◽  
Time History ◽  
Lateral Force ◽  
Time History Analysis ◽  
Force Distribution ◽  
Structural Elements ◽  
Moment Frame ◽  
History Analysis ◽  
Displacement Based ◽  
Special Moment Frame

Reinforced concrete Special Moment Frame (RC-SMF) with irregularity in dimension experiences large inelastic deformation under ground motion. The building code for designing structural elements generally is focused on satisfying the strength and serviceability. On the other hand, the displacement-based design (DBD) procedure is based on building performance level. This paper presents a devoted study of designing structural elements of 8 story RC-SMF with vertical irregularity using the DBD method. This method is mainly using energy-work balance concept with pre-selected yield mechanism and target drift. Moreover, a new lateral force distribution method is used in this study which accounts for inelastic dynamic response and higher mode effects. Strong column-weak beam mechanism is used to design beam and column, and beam moment capacity of each floor is calculated by equating external work to internal work approach. Furthermore, column design strength is taken as the combination of factored gravity loads and maximum expected strength of the beam. The time history analysis results show that story drift is below than the target drift and achieve the desired performance level. Moreover, the results also show lateral force distribution is very close to the lateral shear distribution which obtained from time history analysis.

Metaheuristic Optimization of Reinforced Concrete Frames

2020 ◽  
pp. 141-160
Keyword(s):  
Reinforced Concrete ◽  
Optimum Design ◽  
Harmony Search ◽  
Time History ◽  
Rc Frame ◽  
Concrete Frames ◽  
Design Constraints ◽  
Rc Frames ◽  
History Analysis ◽  
Internal Forces

In this chapter, an optimum design methodology for reinforced concrete (RC) frames are presented. In the optimum design of frames, both beams and columns are optimized. In addition to that, internal forces can be modified according to rigidity of members for statically indetermined frames. In the presented methodology, the optimization of RC frame is done according to dynamic seismic loads and the design is done according to time-history analysis. As a metaheuristic algorithm, a modified harmony search is used, and the design constraints are provided according to ACI 318: Building code requirements for structural concrete. The optimum results of two span-two story symmetric RC frames and three span-three story RC frame are presented.

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