scholarly journals Evaluation of elastic stiffness factor of 2D reinforced concrete frame system with different parameters

2021 ◽  
Vol 2 (2) ◽  
pp. 26-31
Author(s):  
Omar Ahmad
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Elastic Stiffness ◽  
Span Length ◽  
Base Shear ◽  
Reinforced Concrete Frame ◽  
Plastic Hinges

In general, the buildings are designed based on the applied loads on them, and these buildings generally have elastic structural behaviour. However, these structures may be subjected to unexpectedly strong seismic forces that exceed their elastic limits. In order to find the rigidity and load-bearing trend of the building without the formation of plastic hinges and failure, pushover analysis should be performed. Pushover analysis is a non-linear static analysis in which the structure is subjected to lateral loads, so some parameters are recorded, such as failure, formation of plastic hinges, and yield. The elastic stiffness factor is the ability of a building to bear the loads on it before the failure and existent of the plastic hinges. In this study, pushover analysis had been done on 12 two-dimensional reinforced concrete frames with a different number of stories, different span lengths and with or without shear walls to find the effect of the span length, shear wall and the number of stories on the elastic stiffness factor. After performing the pushover analysis, the elastic stiffness factor had been evaluated from the pushover curve by dividing the base shear over the lateral displacement at the first point of the occurrence of the plastic hinge. The results obtained from the study showed that the elastic stiffness factor increases with the increase of the span length, while it decreases with the increase of the number of stories. As well, the frames with shear walls are stiffer than the frames without shear walls.

scholarly journals Assessment of plastic hinge in RC structures with and without shear walls applying pushover analysis

2020 ◽  
Vol 1 (1) ◽  
pp. 11-18
Author(s):  
Jean Pierre Lukongo Ngenge ◽  
Abdallah M. S. Wafi
Keyword(s):  
Plastic Hinge ◽  
Pushover Analysis ◽  
Computer Software ◽  
Shear Walls ◽  
Span Length ◽  
Base Shear ◽  
Rc Structures ◽  
High Rise ◽  
Moment Resisting Frames ◽  
Moment Resisting

This paper gives a brief presentation about different types of analysis, plastic hinge, moment-resisting frames (MRFs) and shear walls (SWs) in reinforced concrete (RC) Structures. ETABS computer software is employed to model and analyse the structures applying the pushover. The performances of the modelled structures are also evaluated considering different parameters such as the number of stories, spans length, shear walls, reinforcement yield strength and characteristic strength of concrete. The study includes two cases, which are moment-resisting frames with and without shear walls (i.e. MRFs and MRF-SWs, respectively). Each case covers low-, mid- and high-rise buildings. In this regard, a comparative study has been performed for the results obtained from all models. It was observed that the stiffness of MRFs compared to MRF-SWs was less and also the stiffness of low-rise frames was higher than that of mid-rise and high-rise frames. Technically this means that a low-rise building is stiffer than a mid-rise building and a mid-rise building is stiffer than a high-rise building. Additionally, when the span length increases, the stiffness of the building decreases. Therefore, it can be concluded that the span length is inversely proportional to the stiffness. Finally, all stiffness values were calculated taking into consideration the displacement and base shear at the first hinge formation on the pushover curve of each model.

scholarly journals Probabilistic pushover analysis of reinforced concrete frame structures using dropout neural network

2021 ◽  
Vol 15 (1) ◽  
pp. 30-40
Author(s):  
Dang Viet Hung ◽  
Nguyen Truong Thang ◽  
Pham Xuan Dat
Keyword(s):  
Machine Learning ◽  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Training Data ◽  
Data Driven ◽  
Frame Structures ◽  
Nonlinear Phenomena ◽  
Base Shear

When taking into consideration nonlinear phenomena such as material plasticity, plastic hinge, and P-Delta effect, the pushover analysis can provide more realistic structures’ nonlinear responses. However, this method is not widely used in practice as it is more complex and requires more expertise than elastic approaches. On the other hand, the data-driven method emerges as an increasingly appealing alternative since it requires only input parameters, then directly yields results in conditions that enough training data are provided, as well as an appropriate machine learning model is devised. Thus, this study develops a probabilistic data-driven approach using the Multiple Layer Perceptron network coupled with the Dropout mechanism to perform the pushover analysis of reinforced concrete (RC) frame structures, predicting base shear, lateral displacement, as well as their relationship between the two formers. Moreover, corresponding confidence intervals of predicted values are also available owing to the probabilistic nature of the method, thus helping engineers design conservative solutions. Keywords: pushover analysis; reinforced concrete; structure; probabilistic analysis; machine learning; dropout mechanism; OpenSees.

scholarly journals Evaluation of plastic hinges performance and the elastic stiffness factor of moment-resisting frame structures

2020 ◽  
Vol 1 (3) ◽  
pp. 10-17
Author(s):  
Khosro Zehro ◽  
Shahram Jkhsi
Keyword(s):  
Lateral Displacement ◽  
Structural Parameters ◽  
Plastic Hinge ◽  
Elastic Stiffness ◽  
Base Shear ◽  
Plastic Hinges ◽  
Rc Structures ◽  
Wide Range ◽  
Moment Resisting ◽  
Nonlinear Static

Nowadays, to analyse and determine the maximum seismic lateral displacement for reinforced concrete (RC) structures, the most applicable procedure used by structural engineers is the nonlinear static (pushover) analysis. The nonlinear static procedure (NSP) is a common approach for analysing the seismic performance of construction structures. By directing this procedure, the weak points in each structural member can be examined, and it also determines whether the members are safe or need to rehabilitate. This process defines the level of performance and shear strength under seismic diffusion to construct each element of the structure. The displacement, the base shear, the plastic hinge model, and the effect of the different plan on seismic response of structures has been reported. When concentrating on the RC structures, it requires the ability to conduct lateral resistant force systems, which one of them is commonly known as moment-resisting frames (MRFs). In this paper, three models of RC structures considered for low-, medium-, and high-rise buildings were examined, and each model has been analysed for three different spans. These models have been analysed applying ETABS software by inputting and examining a wide range of structural parameters. A comprehensive study on the pushover curve, performance curve, among others have been performed. The aim of this study is to consider the effect of plastic hinges in various ranges of performance capacities to evaluate the elastic stiffness factor of structures

Performance-Based Pushover Analysis for Reinforced Concrete Frame

2011 ◽  
Vol 255-260 ◽  
pp. 2426-2433
Author(s):  
Hui Zhi Zhang ◽  
Xiu Qin Cui
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Time History ◽  
Bending Moment ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
History Analysis ◽  
Hinge Bending ◽  
Stable Result

For more reasonable and convenient evaluating structure seismic performance,static elasto-plastic analysis of reinforced concrete frame is presented by pushover with different lateral load distributing modes including uniform distribution, inverted triangle distribution and self-adaption distribution adopted, custom plastic hinge, bending moment-curvity relation and bending moment-axial force correlation of each member section are acquired by Response2000, and time history analysis is used to reinforced concrete frame. It is revealed that the presented method is easy and feasiable, and can generatee stable result.

scholarly journals Seismic Behavior of RCS Composite Frame Structure with Rigidity Zone Factor Variations of Beam-Column Connections

2021 ◽  
Vol 27 (1) ◽  
pp. 41-50
Author(s):  
I Ketut Sudarsana ◽  
I Gede Adi Susila ◽  
Ni Wayan Sastraningsih
Keyword(s):  
Seismic Behavior ◽  
Pushover Analysis ◽  
Seismic Energy ◽  
Elastic Stiffness ◽  
Frame Structure ◽  
Base Shear ◽  
Plastic Hinges ◽  
Linear Elastic ◽  
Total Potential ◽  
Composite Frame

This research evaluated the effect of connection’s rigidity zone factors of RCS frame’s connections on the seismic behavior of regular RCS frames of a five-story office building located at seismic design category (SDC) of D. The variations on rigidity zone factors were 0, 0.25, 0.50, 0.75, and 1.0, respectively for Model MS, MSR025, MSR05 MSR075, and MR with the same elements’ dimension. A 3-D finite element modeling was conducted to do a linear elastic analysis for structural design and nonlinear static pushover analysis for evaluating the structural seismic performance. The results show that all models have met the strength and serviceability design limits. The seismic performances in terms of base shear, elastic stiffness, and ductility of all RCS models increased with an increase in the values of the rigidity zone factor. The structural performance level according to FEMA 440 was life safety (LS) for the Model MSR05, MSR075, and MR, while for the Model MS and MSR025 was collapse prevention (CP). The seismic energy dissipation for all RCS frames was an intermediate category indicated by the numbers of developed plastic hinges less than 20% of the total potential plastic hinges

scholarly journals Bracing Applications for Improving the Earthquake Performance of Reinforced Concrete Structures

2020 ◽  
Vol 9 (3) ◽  
pp. 2179-2182
Keyword(s):  
Reinforced Concrete ◽  
Pushover Analysis ◽  
Concrete Structures ◽  
Shear Walls ◽  
Lateral Load ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Base Shear ◽  
Braced Frame ◽  
Rc Frames

Braced frames, besides other structural systems, such as shear walls or moment resisting frames, have been a valuable and effective technique to increase structures performance against seismic loads. In wind or seismic excitations, diagonal members react as truss web elements which would afford tension or compression stresses. This study purposes at considering the effect of bracing diagonals on values of base shear and displacement of building. Two models were created and nonlinear pushover analysis has been implemented. Results show that bracing members enhance the lateral load performance of RC frames considerably. The purpose of this article is to study the nonlinear response of reinforced concrete Structures which contain Hollow Pipe Steel braces as the major structural elements versus earthquake loads. A five-storey reinforced concrete structure was selected in this study; two different reinforced concrete frames were considered. The first system was un-braced frame while the last one was braced frame with diagonal bracing. Analytical modelings of the bare frame and braced frame were realized by means of SAP 2000. The performances of all structures were evaluated using the nonlinear static analyses. From these analyses, the base shear and displacements were compared. Results are plotted in diagrams and discussed extensively and the results of the analyses showed that, the braced frame was seemed to capable of more lateral load carrying, had the high value for stiffness and lower roof displacement in comparison with bare frame.

scholarly journals Behavioural Study of Shear Wall with Correlational to Bracing under Seismic Loading

2018 ◽  
Vol 65 ◽  
pp. 08008
Author(s):  
Syed Muhammad Bilal Haider ◽  
Zafarullah Nizamani ◽  
Chun Chieh Yip
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Limit State ◽  
Shear Wall ◽  
Design Tool ◽  
Base Shear ◽  
Building Model ◽  
High Rise ◽  
Finite Element Software ◽  
Seismic Vibrations

The reinforced concrete structures, not designed for seismic conditions, amid the past earthquakes have shown us the significance of assessment of the seismic limit state of the current structures. During seismic vibrations, every structure encountered seismic loads. Seismic vibrations in high rise building structure subjects horizontal and torsional deflections which consequently develop extensive reactions in the buildings. Subsequently, horizontal stiffness can produce firmness in the high rise structures and it resists all the horizontal and torsional movements of the building. Therefore, bracing and shear wall are the mainstream strategies for reinforcing the structures against their poor seismic behaviours. It is seen before that shear wall gives higher horizontal firmness to the structure when coupled with bracing however it will be another finding that in building model, which location is most suitable for shear wall and bracing to get better horizontal stability. In this study, a 15 story residential reinforced concrete building is assessed and analyzed using building code ACI 318-14 for bracing and shear wall placed at several different locations of the building model. The technique used for analysis is Equivalent Static Method by utilizing a design tool, finite element software named ETABS. The significant parameters examined are lateral displacement, base shear, story drift, and overturning moment.

Investigation of Plastic Hinge Length in Reinforced Concrete Columns on Column Behavior

2017 ◽  
Vol 21 ◽  
pp. 45-49
Author(s):  
Mehmet Kamanli ◽  
Alptug Unal
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Concrete Columns ◽  
Analysis Program ◽  
Reinforced Concrete Buildings ◽  
Reinforced Concrete Columns ◽  
Concrete Buildings ◽  
Horizontal Stability ◽  
Plastic Hinge Length

In reinforced concrete buildings in case of a possible earthquake, the buildings slamp as they lost their horizontal stability because of hinging of column ends. The assumptions for plastic hinge lengths are present during project stage of reinforced concrete buildings. According to Turkish Earthquake Regulations, although plastic hinge length is determined to be 0.5h, it's known that plastic hinge length is determined via various formulas in some other regulations all over the world. In reinforced concrete columns, it's necessary to indicate the effect of plastic hinge length on the column behavior. For this purpose, pushover analysis of 5 column samples having different plastic hinge lengths was performed with non-linear analysis program. As a result of pushover analysis, situations of plastic hinges formed in columns and their load-displacement curves were determined. The graphs and the data were compared and the results were discussed.

The Plastic Hinge

2015 ◽  
pp. 172-230
Keyword(s):  
Reinforced Concrete ◽  
Structural Analysis ◽  
Plastic Hinge ◽  
Steel Frames ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Plastic Hinges

The plastic hinge is a key concept of the theory of frames that differentiates this theory from the remaining models for structural analysis. This chapter is exclusively dedicated to define this concept and describe the different models of plastic hinges. It also discusses the differences of implementation between plastic hinges in steel frames (Sections 6.1-6.4) and those in reinforced concrete structures (Sections 6.5-6.6). This chapter is based on the ideas presented in Chapter 5 and it allows formulating the models for elasto-plastic frames that are introduced in the next chapter.

scholarly journals Shear model with shear-flexure interaction for non-linear analysis of reinforced concrete frame element

2018 ◽  
Vol 192 ◽  
pp. 02003
Author(s):  
Worathep Sae-Long ◽  
Suchart Limkatanyu
Keyword(s):  
Reinforced Concrete ◽  
Interaction Effect ◽  
Plastic Hinge ◽  
Shear Stiffness ◽  
Reinforced Concrete Frame ◽  
Shear Model ◽  
Concrete Frame ◽  
Frame Element ◽  
Proposed Model ◽  
Frame System

This paper presents the shear constitutive model for the reinforced concrete (R/C) frame structures analysis under monotonic and cyclic loading. The proposed model is adopted and modified from Mergos and Koppos model [1] that accounts the shear stiffness degradation effect by the shear-flexure interaction in the plastic hinge region. Firstly, the proposed shear model starts from the primary curve without the damages due to the shear-flexure interaction effect. Then, the shear-flexure interaction effect is taken into consideration at the locations of plastic hinges and this effect leads to the degradation of the shear strength and shear stiffness on the undamaged primary curve that is replaced with the damaged primary curve. To determine the sectional shear stiffness with the shear-flexure interaction, an alternative way of the iterative procedure is proposed here. Finally, a numerical example is used to verify the characteristics and behavior of the R/C frame system and confirm accuracy and computational efficiency of the proposed model among the experimental data.

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