scholarly journals 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.

scholarly journals Displacement Demand for Nonlinear Static Analyses of Masonry Structures: Critical Review and Improved Formulations

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 118
Author(s):  
Gabriele Guerrini ◽  
Stylianos Kallioras ◽  
Stefano Bracchi ◽  
Francesco Graziotti ◽  
Andrea Penna
Keyword(s):  
Time History ◽  
Nonlinear Static Analysis ◽  
Equivalent Linearization ◽  
Eurocode 8 ◽  
Masonry Structures ◽  
Equivalent Viscous Damping ◽  
Inelastic Displacement ◽  
N2 Method ◽  
Nonlinear Static ◽  
Nonlinear Time History

This paper discusses different formulations for calculating earthquake-induced displacement demands to be associated with nonlinear static analysis procedures for the assessment of masonry structures. Focus is placed on systems with fundamental periods between 0.1 and 0.5 s, for which the inelastic displacement amplification is usually more pronounced. The accuracy of the predictive equations is assessed based on the results from nonlinear time-history analyses, carried out on single-degree-of-freedom oscillators with hysteretic force–displacement relationships representative of masonry structures. First, the study demonstrates some limitations of two established approaches based on the equivalent linearization concept: the capacity spectrum method of the Dutch guidelines NPR 9998-18, and its version outlined in FEMA 440, both of which overpredict maximum displacements. Two codified formulations relying on inelastic displacement spectra are also evaluated, namely the N2 method of Eurocode 8 and the displacement coefficient method of ASCE 41-17: the former proves to be significantly unconservative, while the latter is affected by excessive dispersion. A non-iterative procedure, using an equivalent linear system with calibrated optimal stiffness and equivalent viscous damping, is then proposed to overcome some of the problems identified earlier. A recently developed modified N2 formulation is shown to improve accuracy while limiting the dispersion of the predictions.

scholarly journals Evaluation of p-delta effect in structural seismic response

2018 ◽  
Vol 162 ◽  
pp. 04019 ◽  
Author(s):  
Sardasht Sardar ◽  
Ako Hama
Keyword(s):  
Seismic Response ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Steel Structure ◽  
Nonlinear Static Analysis ◽  
Structural Behavior ◽  
Finite Element Software ◽  
History Analysis ◽  
Nonlinear Static

Numerous recent studies have assessed the effect of P-Delta on the structures. This paper investigates the effect of P-Delta in seismic response of structures with different heights. For indicating the effect of P-Delta, nonlinear static analysis (pushover analysis) and nonlinear dynamic analysis (Time history analysis) were conducted by using finite element software. The results showing that the P-Delta has a significant impact on the structural behavior mainly on the peak amplitude of building when the height of the structures increased. In addition, comparison has been made between concrete and steel structure.

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

2014 ◽  
Vol 8 (1) ◽  
pp. 310-323 ◽  
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.

scholarly journals Seismic Evaluation and Retrofitting of an Existing Buildings-State of the Art

2021 ◽  
Vol 24 (1) ◽  
pp. 52-75
Author(s):  
Haider Ali Abass ◽  
Husain Khalaf Jarallah
Keyword(s):  
Static Analysis ◽  
Pushover Analysis ◽  
Performance Based Design ◽  
Nonlinear Static Analysis ◽  
Building Structures ◽  
Seismic Evaluation ◽  
Modern Approach ◽  
Existing Building ◽  
Damage And Failure ◽  
Nonlinear Static

In this study, previous researches were reviewed in relation to the seismic evaluation and retrofitting of an existing building. In recent years, a considerable number of researches has been undertaken to determine the performance of buildings during the seismic events. Performance based seismic design is a modern approach to earthquake resistant design of reinforcement concrete buildings. Performance based design of building structures requires rigorous non-linear static analysis. In general, nonlinear static analysis or pushover analysis was conducted as an efficient instrument for performance-based design. Pushover analysis came into practice after 1970 year.  During the seismic event, a nonlinear static analysis or pushover analysis is used to analyze building under gravity loads and monotonically increasing lateral forces. These building were evaluated until a target displacement reached. Pushover analysis provides a better understanding of buildings seismic performance, also it traces the progression of damage and failure of structural components of buildings. 

scholarly journals Special Moment Resistant Steel Buildings

2021 ◽  
pp. 444-448
Author(s):  
Deepan Dev B ◽  
Dr V Selvan
Keyword(s):  
Pushover Analysis ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Building Structures ◽  
Braced Frames ◽  
Steel Buildings ◽  
Braced Frame ◽  
Moment Resisting ◽  
Frame Systems ◽  
Nonlinear Time History

The seismic response of special moment-resisting frames (SMRF), buckling restrained braced (BRB) frames and self-centering energy dissipating (SCED) braced frames is compared when used in building structures many stories in height. The study involves pushover analysis as well as 2D and 3D nonlinear time history analysis for two ground motion hazard levels. The SCED and BRB braced frames generally experienced similar peak interstory drifts. The SMRF system had larger interstory drifts than both braced frames, especially for the shortest structures. The SCED system exhibited a more uniform distribution of the drift demand along the building height and was less prone to the biasing of the response in one direction due to P-Delta effects. The SCED frames also had significantly smaller residual lateral deformations. The two braced frame systems experienced similar interstory drift demand when used in torsional irregular structures.

scholarly journals Comparative Study of Nonlinear Static and Time-History Analyses of Typical Korean STS Container Cranes

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Quang Huy Tran ◽  
Jungwon Huh ◽  
Van Bac Nguyen ◽  
Achintya Haldar ◽  
Choonghyun Kang ◽  
...  
Keyword(s):  
Time History ◽  
Linearization Method ◽  
Nonlinear Static Analysis ◽  
Equivalent Linearization ◽  
Base Shear ◽  
Container Cranes ◽  
Container Crane ◽  
Total Base ◽  
Nonlinear Static ◽  
Nonlinear Time History

Ship-to-shore (STS) container gantry cranes, used at terminals for loading and unloading containers from a ship, are an important part of harbor structures. The size and weight of modern STS container cranes are increasing to satisfy the demand for bigger ships. This is expected to result in more lateral load when excited by seismic motions. The existing Korean STS container cranes did not behave properly during several recent moderate earthquakes in South Korea. Typical Korean STS container cranes must be checked for the earthquake-resistant capacity. In this research, two nonlinear static analyses procedures, also known as pushover analyses, commonly used for seismic design of buildings, namely, capacity spectrum method and equivalent linearization method, are comprehensively studied to check their suitability for studying seismic behavior of STS cranes. Results obtained by these two nonlinear static analysis methods are then compared with the results obtained by nonlinear time-history analyses of the STS cranes by exciting them with nine recorded earthquake time histories around worldwide. The behaviors of the cranes are analyzed in terms of the total base shear, drift, and base uplift. The comparisons indicate that the nonlinear static methods can be appropriate for estimating the total base shear and drift of the portal frame of a container crane. The pushover analyses also provide information on performance levels as defined in ASCE/SEI 41-13, of a typical Korean STS container crane. Furthermore, it is observed that the uplift response of the crane is strongly influenced by the duration of an earthquake.

Applying Adaptive Pushover Analysis to Estimate Incremental Dynamic Analysis Curve

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.

Nonlinear Static Analysis Method

2021 ◽  
pp. 285-344
Keyword(s):  
Reinforced Concrete ◽  
Time History ◽  
Nonlinear Static Analysis ◽  
Nonlinear Time History Analysis ◽  
Eurocode 8 ◽  
Test Bed ◽  
Reinforced Concrete Building ◽  
Concrete Building ◽  
Nonlinear Static ◽  
Nonlinear Time History

This chapter presents the nonlinear static methods of analyses for seismic design of structures considered by Eurocode 8. The first method is the nonlinear pushover procedure, which is based on the N2 method. The second method is the classical nonlinear time history analysis. The first method is studied in more detail, because the second method is a well-established procedure whose only drawback is the time necessary for the analyses. Nonlinear solvers and procedure in program Z_Soil are described. After a simple nonlinear SDOF application, a test-bed application consisting of an existing two-story reinforced concrete building in Bonefro, Italy is used to compare the two nonlinear procedures. The selected building is representative of typical residential building construction in Italy in the 1970s and 1980s. The aim of this chapter section is to compare 2D and 3D procedures implemented in Z_Soil software. The second example is a 14-story reinforced concrete building designed according to the Algerian code using Sap2000 software.

scholarly journals Nonlinear static analysis of a pile-supported wharf

2019 ◽  
Vol 12 (5) ◽  
pp. 998-1009 ◽  
Author(s):  
E. ZACCHEI ◽  
P. H. C. LYRA ◽  
F. R. STUCCHI
Keyword(s):  
Static Analysis ◽  
Pushover Analysis ◽  
The Body ◽  
Nonlinear Static Analysis ◽  
Environmental Damage ◽  
Structural Behaviour ◽  
Ground Acceleration ◽  
Critical Elements ◽  
Nonlinear Static ◽  
Oil Tankers

Abstract The aim of this paper is to carry out a nonlinear static analysis using a case study of a pile-supported wharf in a new oil tankers port. The seismic activity in this area is very intense with the peak ground acceleration of 0.55 g; for this reason, it is very important to analyse the structural behaviour of the nonlinear situation. The analysis of the wharf, modelled in 3D by finite element method, serves to calculate the structure vibration periods (the structure’s first period is 1.68 s) and the capacity curve. The design of the structure follows traditional criteria by international guidelines, and its procedure is in accordance to classic theoretical methods and codes. For the selection of adequate characteristic earthquake input for the pushover analysis European and Venezuelan codes have been used. Besides being important to study the seismic influence on the body of the wharf and on critical elements, as well as and the interaction fluid-structure-soil, it is also important to analyse the consequences of structure failure and to estimate the maximum allowed displacement. The results show that the ultimate displacement is 18,81 cm. A port is an extremely strategic work, which needs to be carefully designed to avoid environmental damage and maintain human safety.

Verification of spectral reduction factors for seismic assessment of bridges

2009 ◽  
Vol 42 (2) ◽  
pp. 111-121 ◽  
Author(s):  
C. Casarotti ◽  
R. Monteiro ◽  
R. Pinho
Keyword(s):  
Energy Dissipation ◽  
Static Analysis ◽  
Time History ◽  
Degree Of Freedom ◽  
Nonlinear Static Analysis ◽  
Mdof Systems ◽  
Spectral Reduction ◽  
Energy Dissipation Capacity ◽  
Nonlinear Static ◽  
Reduction Factors

Within a nonlinear static analysis procedure perspective for the assessment of structures, one of the key issues is the employment of a demand spectrum that takes also into account, through an adequate reduction of its spectral ordinates, the hysteretic energy dissipation capacity of the structure being assessed. There are certainly a relatively large number of past parametric studies dedicated to the validation of different approaches to translate such structural energy dissipation capacity into spectral reduction factors, however such studies have focused mainly, if not exclusively, on single-degree-of-freedom (SDOF) systems. It seems, therefore, that verification on full structural systems, such as complete bridges, is conspicuously needed in order to verify the adequacy of using existing SDOF-derived relationships in the assessment of multiple-degree-of-freedom (MDOF) systems. In this work, eleven different spectral reduction proposals, involving diverse combinations of previously proposed equivalent damping and spectral reduction equations, are evaluated, for various intensity levels, using a preliminarily validated nonlinear static procedure. A wide set of bridges, covering regular and irregular configurations as well as distinct support conditions, is used. The accuracy of the results is checked by direct comparison with Time-History Analyses performed with ten real ground motion records. Overall conclusions are then presented with the purpose of providing practitioners and researchers with indications on the most adequate spectral reduction schemes to be employed in nonlinear static analysis of bridges.

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