Blast Demand Estimation of RC-Moment-Resisting Frames using a Proposed Multi-modal Adaptive Pushover Analysis Procedure

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.

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Accuracy of Advanced Methods for Nonlinear Static Analysis of Steel Moment-Resisting Frames

The Open Construction and Building Technology Journal ◽

10.2174/1874836801408010310 ◽

2014 ◽

Vol 8 (1) ◽

pp. 310-323 ◽

Cited By ~ 9

Author(s):

Massimiliano Ferraioli ◽

Alberto M. Avossa ◽

Angelo Lavino ◽

Alberto Mandara

Keyword(s):

Pushover Analysis ◽

Nonlinear Static Analysis ◽

Seismic Demands ◽

Steel Moment Resisting Frames ◽

Moment Resisting Frames ◽

Capacity Spectrum ◽

History Analysis ◽

Moment Resisting ◽

Response History Analysis ◽

Nonlinear Static

The reliability of advanced nonlinear static procedures to estimate deformation demands of steel momentresisting frames under seismic loads is investigated. The advantages of refined adaptive and multimodal pushover procedures over conventional methods based on invariant lateral load patterns are evaluated. In particular, their computational attractiveness and capability of providing satisfactory predictions of seismic demands in comparison with those obtained by conventional force-based methods are examined. The results obtained by the static advanced methods, used in the form of different variants of the original Capacity Spectrum Method and Modal Pushover Analysis, are compared with the results of nonlinear response history analysis. Both effectiveness and accuracy of these approximated methods are verified through an extensive comparative study involving both regular and irregular steel moment resisting frames subjected to different acceleration records.

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Plastic hinge assessment of RC moment-resisting frames

International Journal of Advanced Engineering, Sciences and Applications ◽

10.47346/ijaesa.v1i3.29 ◽

2020 ◽

Vol 1 (3) ◽

pp. 37-41

Author(s):

Mahmoud Alhassan ◽

Mohamad Abdelrahim

Keyword(s):

Plastic Hinge ◽

Pushover Analysis ◽

Computer Software ◽

Elastic Stiffness ◽

Frame Structure ◽

Nonlinear Static Analysis ◽

Rc Structures ◽

Moment Resisting Frames ◽

Moment Resisting ◽

Fundamental Reason

This paper gives a short introduction about various kinds of analysis, plastic hinges, moment-resisting frames (MRFs) in RC Structures. It likewise gives computer software ETABS displaying and an investigation of structures concerning Pushover Analysis. The fundamental reason for this examination is to apply a push to all models, analyse and get a reasonable thought regarding their behaviour. The behaviour of these structures likewise was evaluated considering various variables such as the changes in the number of floors, spans length, reinforcements' yield strength and characteristic strength of concrete. This investigation incorporates the moment-resisting frames (MRFs) having 4, 7, and 10 storeys and a relative report for all models' outcomes. Pushover analysis is a nonlinear static analysis used to determine the relationship between strength and displacement in order to evaluate the performance of the RC frame structure. It was found that the plastic hinge may be assessed using parameters such as span lengths and the number of storeys. When the number of storeys increases, the elastic stiffness value decreases and when the span length increases the elastic stiffness also decreases. The collapse of members happens only when there is a formation of 3 hinge mechanisms. Plastic hinge colours have been given, and each colour has its significance to permit a good design.

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Adaptive Pushover Analysis of Irregular RC Moment Resisting Frames

10.29007/pbdr ◽

2018 ◽

Author(s):

Rutvik Sheth ◽

Devesh Soni ◽

Minoli Shah

Keyword(s):

Static Analysis ◽

Pushover Analysis ◽

Time History ◽

Nonlinear Static Analysis ◽

Seismic Zone ◽

Fundamental Vibration ◽

Moment Resisting ◽

Nonlinear Static ◽

Adaptive Pushover ◽

Nonlinear Time History

Researchers and engineers certainly prefer to use nonlinear static methods over complicated nonlinear time-history methods. However, in nonlinear static procedure both predetermined target displacement and force distribution pattern are based on a false assumption that the structural behavior and its responses are dominated by the fundamental vibration modes. Therefore, over the past decades, there have been a great number of studies on considering higher mode contribution in nonlinear static results. The Displacement-based Adaptive Pushover Analysis (DAP) is one of the performance assessments tool for improving the accuracy of the obtained results of nonlinear static analysis in estimating the seismic demands of the structures. In this paper, 5 storey L- shaped RC frame is analyzed for seismic Zone IV and designed as per provisions of IS codes. Performance evaluation is carried out by nonlinear static analysis as well as adaptive pushover analysis and results are compared.

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Applying Adaptive Pushover Analysis to Estimate Incremental Dynamic Analysis Curve

Journal of Earthquake and Tsunami ◽

10.1142/s1793431120500165 ◽

2020 ◽

Vol 14 (04) ◽

pp. 2050016

Author(s):

Hamid Reza Ahmadi ◽

Navideh Mahdavi ◽

Mahmoud Bayat

Keyword(s):

Dynamic Analysis ◽

Limit State ◽

Pushover Analysis ◽

Computational Cost ◽

Time History ◽

Incremental Dynamic Analysis ◽

History Analysis ◽

Moment Resisting ◽

Displacement Based ◽

Adaptive Pushover

To estimate seismic demand and capacity of structures, it has been suggested by researchers that Incremental Dynamic Analysis (IDA) is one of the most accurate methods. Although this method shows the most accurate response of the structure, some problems, such as difficulty in modeling, time-consuming analysis and selection of the earthquake records, encourage researchers to find some ways to estimate the dynamic response of structures by using static nonlinear analysis. The simplicity of pushover analysis in evaluating structural nonlinear response serves well as an alternative to the time-history analysis method. In this paper, based on the concepts of the displacement-based adaptive pushover (DAP), a new approach is proposed to estimate the IDA curves. The performance of the proposed method has been investigated using 3- and 9-story moment-resisting frames. In addition, the results were compared with exact IDA curves and IDA curves developed by the modal pushover analysis (MPA) based method. For evaluation, IDA curves with 16%, 50% and 84% fractile were estimated. Using the results, [Formula: see text] capacities corresponding to Collapse Prevention (CP) limit state were calculated and assessed. Finite element modeling of the structures has been carried out by using ZEUS-NL software. Based on the achieved results, the proposed approach can estimate the capacity of the structure accurately. The significant advantage of the applied approach is the low computational cost and desirable accuracy. The proposed approach can be used to develop the approximate IDA curves.

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