scholarly journals Effect of ‘X’ Type Bracing on Response Modification Factor for R.C. Building with Special Shaped Column Cross Sections

2021 ◽  
Vol 9 (VI) ◽  
pp. 4755-4762
Author(s):  
Baviskar Vinita
Keyword(s):  
Seismic Design ◽  
Cross Sections ◽  
Pushover Analysis ◽  
Lateral Force ◽  
Developed Countries ◽  
Structural Aspect ◽  
Damping Factor ◽  
Base Shear ◽  
Response Modification Factor ◽  
Modification Factor

Earthquake is the most destructive natural hazard in the world. While designing any earthquake resistant structure, actual forces developed are much higher than designed forces. Therefore, to get design lateral force, the actual base shear force should be reduced by the factor known as response modification factor(R). Response modification factor plays vital role in seismic design of structures. Components of response modification factor (R) are ductility factor, over strength factor, redundancy factor and damping factor. Generally, value of response modification factor is adopted from seismic design codes of developed countries such as Europe, United States and India. Column is important part of Reinforced concrete building as overall load is transferred through column. Not only from aesthetical point of view, but also from structural aspect special shaped columns performs better than rectangular columns. So this study aims at calculating components of response modification factor(R) for column cross section with special shapes (L, T, +) for ‘X’ type bracing. In this study total 16 models of different number of storeys i.e. 5,10 are analysed using Pushover analysis for different seismic zones. The study also involves comparison of response modification factor (R) for structures designed with Indian code IS1893:2016(Part1) and American code ASCE 7-16.

Response Modification Factor for Y-Eccentric-Braced Steel Frame Structures

2011 ◽  
Vol 250-253 ◽  
pp. 2285-2290
Author(s):  
Wen Xia Yang ◽  
Qiang Gu ◽  
Zhen Sen Song
Keyword(s):  
Seismic Design ◽  
Pushover Analysis ◽  
Steel Frames ◽  
Design Procedure ◽  
Response Spectra ◽  
Elastic Response ◽  
Base Shear ◽  
Response Modification Factor ◽  
Elastic Response Spectra ◽  
Modification Factor

In current seismic design procedure, structural base shear is calculated according to the linear elastic response spectra divided by response modification factorR. The response modification factor is important to the reliability and economy of building seismic design. In this paper, the response modification factors of Twelve Y-eccentric braced steel frames with various stories and spans lengths were evaluated by capacity spectrum method based on the global capacity envelops obtained from an improved pushover analysis and incremental dynamic analysis. According to the results, an appropriate formula of the response modification factor for the Y-eccentric braced steel frames was suggested.

Response Modification Factor for Y-Eccentric-Braced Steel Frame Structures Designed Based on Chinese Code

2014 ◽  
Vol 580-583 ◽  
pp. 1449-1457
Author(s):  
Wen Xia Yang ◽  
Qiang Gu ◽  
Ping Zhou Cao ◽  
Rong Jin Shi
Keyword(s):  
Pushover Analysis ◽  
Design Procedure ◽  
Response Spectra ◽  
Elastic Response ◽  
Base Shear ◽  
Response Modification Factor ◽  
Linear Elastic ◽  
Elastic Response Spectra ◽  
Modification Factor ◽  
Steel Frame Structures

In current seismic design procedure, structure base shear is calculated according to the linear elastic response spectra divided by the response modification factor, which accounts for ductility and overstrength of a structural system. In this paper, the response modification factors of Y-eccentric braced steel frames (YECBF) designed based on Chinese Code were evaluated by an improved pushover analysis on 12 examples with various stories and spans lengths. According to the analysis results, the effects of fundamental periods, storey numbers, and spans of frames on the behavior factor were studied. In the end, an appropriate response modification factor was proposed for YECBF designed base on Chinese Code.

scholarly journals Effect of Building Configuration on Overstrength Factor and Ductility Factor

2021 ◽  
Author(s):  
Sagun Kandel ◽  
Rajan Suwal
Keyword(s):  
Residential Buildings ◽  
Pushover Analysis ◽  
Large Earthquake ◽  
Lateral Force ◽  
Reduction Factor ◽  
Base Shear ◽  
Response Reduction Factor ◽  
Overstrength Factor ◽  
Ductility Factor ◽  
High Level

It is important for the structure to be economical and still have a high level of life safety. The lateral force sustained by the structures during a large earthquake would be several times larger than the lateral force for which the structures are designed. This is opposite to the fact that design loads such as gravity in codes are usually higher than the actual anticipated load. It is based on the probability that the occurrence of large earthquakes is quite rare and the capacity of the structure to absorb energy. The co-factors of response reduction factor which is the overstrength factor and ductility factor reduce the design horizontal base shear coefficient. A total of 36 low-rise residential buildings having different storey, bay and bay lengths are selected and analysed in this paper. NBC 105: 2020 is selected for the seismic design of RC buildings while provision provided in FEMA 356:2000 is used to carry out non-linear pushover analysis. The results indicated that between the different structures, the value of overstrength factor and ductility factor has a high deviation.

Response Modification Factor of Steel Frames with and Without Dampers

2020 ◽  
Vol 9 (6) ◽  
pp. 950-953
Keyword(s):  
Static Analysis ◽  
Seismic Design ◽  
Numerical Models ◽  
Steel Structures ◽  
Design Stage ◽  
Design Parameters ◽  
Element Analysis ◽  
Response Modification Factor ◽  
Numerical Studies ◽  
Modification Factor

Response modification factor (R) performs as one of the main seismic design parameters of new structures during earthquake and is considered as significant parameter of nonlinear equivalent static analysis which is a widely used method to evaluate the seismic response of a structure. A review of the literature illustrates that although various numerical studies have investigated the effect of viscous dampers on the response modification factor (R), lack of experimental study has been conducted to verify the numerical models. This study evaluates the response modification factor of steel frame with and without viscous damper. Experimental and numerical analysis have been conducted in the present research. It is found that results from finite element analysis agree well with the experimental results. Besides, the use of damper increases significantly the response modification factors of steel structures, e.g., the factor of structures with dampers are approximate 32% higher than the structures without dampers. The determined response modification factors for the different structures used in this study can be applied to conduct equivalent static analysis of buildings as an initial design stage.

RESEARCH INTO THE DEVELOPMENT OF A RESPONSE MODIFICATION FACTOR FOR DIAGRID STRUCTURES

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yasser Salem ◽  
Devindar Aulakh ◽  
Giuseppe Lomiento
Keyword(s):  
Pushover Analysis ◽  
Lateral Loads ◽  
Response Modification Factor ◽  
Ground Shaking ◽  
High Rise ◽  
Non Linear ◽  
Moment Resisting ◽  
Inelastic Behaviour ◽  
Modification Factor ◽  
Diagrid Structure

The diagrid structure system has recently gained popularity as an effective structural system for high rise buildings. The effectiveness of the system relies on the truss action developed by the perimeter diagrid system to resist lateral loads. In active seismic zones, ductile performance of the lateral resisting system is highly desired to dissipate energy developed in the structure from the ground shaking. In this study, the seismic performance of the diagrid system is investigated. Non-linear static pushover analysis followed by non-linear dynamic analysis were conducted to study the inelastic behaviour of diagrid systems. Through methods of analysis, the response modification factor of the modelled system was calculated. The results indicate that the reserve strength of a diagrid system is comparable to and often greater than that of many other lateral structure systems, such as steel special truss moment resisting frames and other structural systems as prescribed by the ASCE 7-10.

The Pushover Analysis of R.C Frames Based on SAP2000

2012 ◽  
Vol 594-597 ◽  
pp. 812-815
Author(s):  
Jing Li ◽  
Xing Hua Yu
Keyword(s):  
Seismic Design ◽  
Design Principle ◽  
Response Spectrum ◽  
Pushover Analysis ◽  
Base Shear ◽  
Plastic Hinges ◽  
Frame Model ◽  
Second Stage ◽  
Basal Shear

The pushover analysis had been done for a R.C frame model, vertex displacement、base shear 、 appear order and development situation of plastic hinges of the model had been get in different steps of pushover analysis, The pictures of basal shear-vertex displacement and response spectrum displacement-accelerated speed had been studied. The analysis results show that ,the R.C frame model correspond with the seismic design principle of stronger column weaker beam ’,and meet the seismic requirements of the first stage and the calculating resistance to collapse of the second stage.

scholarly journals Response Modification Factors for Reinforced Concrete Structures Equipped with Viscous Damper Devices

2017 ◽  
Author(s):  
Heshmatollah Abdi ◽  
Farzad Hejazi ◽  
Mohd Saleh Jaafar ◽  
Izian Binti Abd Karim
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Viscous Damper ◽  
Response Modification Factor ◽  
Finite Element Software ◽  
Modification Factor

The response modification factor is one of the seismic design parameters that determine the nonlinear performance of building structures during strong earthquakes. Most seismic design codes lead to reduced loads. Nevertheless, an extensive review of related literature indicates that the effect of viscous dampers on the response modification factor is no longer considered. In this study, the effect of implementing viscous damper devices in reinforced concrete structures on the response modification factor was investigated. Reinforced concrete structures with different stories were considered to evaluate the values of the response modification factors. A nonlinear statistic analysis was performed with finite element software. The values of the response modification factors were evaluated and formulated on the basis of three factors: strength, ductility, and redundancy. Results revealed that the response modification factors for reinforced concrete structures equipped with viscous damper devices are higher than those for structures without viscous damper devices. The number of damper devices and the height of buildings have significant effects on response modification factors. In view of the analytical results across different cases, we proposed an equation according to the values of damping coefficients to determine the response modification factors for reinforced concrete structures furnished with viscous damper devices.

Displacement-based seismic design of regular reinforced concrete shear wall buildings

2011 ◽  
Vol 38 (6) ◽  
pp. 616-626 ◽  
Author(s):  
JagMohan Humar ◽  
Farrokh Fazileh ◽  
Mohammad Ghorbanie-Asl ◽  
Freddy E. Pina
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Pushover Analysis ◽  
Shear Wall ◽  
Base Shear ◽  
Ductility Demand ◽  
Inelastic Demand ◽  
Displacement Based ◽  
Ductility Capacity ◽  
Shear Demand

A displacement based method for the seismic design of reinforced concrete shear wall buildings of regular shape is presented. For preliminary design, approximate estimates of the yield and ultimate displacements are obtained, the former from simple empirical relations, and the latter to keep the ductility demand within ductility capacity and to limit the maximum storey drift to that specified by the codes. For a multi-storey building, the structure is converted to an equivalent single-degree-of-freedom system using an assumed deformation shape that is representative of the first mode. The required base shear strength of the system is determined from the inelastic demand spectrum corresponding to the ductility demand. In subsequent iterations a pushover analysis for the force distribution based on the first mode is used to obtain better estimates of yield and ultimate displacements taking into account stability under P–Δ effect. A multi-mode pushover analysis is carried out to find more accurate estimates of the shear demand.

scholarly journals Seismic Response Modification Factorof Reinforced Concrete Frames Basedon Pushover Analysis

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Amira Elyamany Mohamed ◽  
Walid A Attia ◽  
Wael M. El-Degwy
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Fundamental Period ◽  
Concrete Frames ◽  
Reinforced Concrete Frames ◽  
Response Modification Factor ◽  
R Factor ◽  
Modification Factor ◽  
The Given

Response modification factor is an essential factor in seismic analysis to provide economic design of reinforced concrete structures. Base shear force is divided by the response modification factor to consider the ability of the structure to dissipate energy through plastic hinges. The current study investigates the effects of changing some parameters on response modification factor (R-factor). Four groups of reinforced concrete frames were studied with different number of bays, number of stories, load pattern, and fundamental period of vibration. All reinforced concrete frames were analyzed using SAP 2000 then the straining actions results were used at specific excel sheets which are developed to design reinforced concrete members according to the Egyptian code of practice ECP-203 and ECP-201. Frames were analyzed by nonlinear static analysis (pushover analysis) using SAP2000. A sum of thirty two systems of frames was analyzed. According to the results, every frame has its unique value of R-factor. Accordingly, many parameters should be mentioned and considered at code to simulate the actual value of R-factor for each frame. Response modification factor is affected by many factors like stiffness, fundamental period of vibration, number of bays, frame height, geometry of the structure, etc. The given values of R-factor at ECP-201 can be considered conservative; as the accurate values of R-factor is higher than the given values.

scholarly journals Performance Behavior of Eccentrically Braced Steel Frame under Seismic Loading

2019 ◽  
Vol 8 (9S) ◽  
pp. 1077-1090
Keyword(s):  
Seismic Event ◽  
Pushover Analysis ◽  
Lateral Force ◽  
Steel Frame ◽  
Braced Frames ◽  
Base Shear ◽  
Eccentrically Braced Frames ◽  
Load Effect ◽  
Story Drift ◽  
Bracing System

Recent past growth of multi-story buildings structures with emphasis on steel has been found satisfactory. For solving the better-quality accommodation in the region where the chances of earthquakes are likely, role of bracing system enhances the performance of building under lateral load effect of earthquakes. Various methods of bracing systems are available in practices however, eccentrically braced frames (EBFs) are fairly new lateral force resisting system established to resist seismic event in a probable manner. Properly designed and detailed EBFs perform in a ductile manner through shear or flexural yielding of link element. The ductile yielding indicates wide hysteresis loop, which is excellent energy dissipation essential for high seismic event. The seismic performance of multi-story steel frame is designed according to the Indian code (IS800:2007). A simple computer-based pushover analysis is a procedure for performance-based design of buildings subjected to earthquake loading. Pushover analysis gets much importance in the past due to its ease and efficiency of the results. In this study eight frames were taken,among these, six frames which were braced as V, Inverted V, and Diagonal and remaining two are frames without bracing in two alternate heights (4 and 8 story). Seismic response of frames is studied using non-linear static analysis (pushover analysis) in terms of base shear, roof displacement, spectral displacement, spectral acceleration and story drift.

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