• Advances in concrete construction
• /
• v.10 no.3
• /
• pp.271-278
• /
• 2020

Quantifying the amount of damage of structures under earthquakes is an interesting issue that researchers have attended on and have presented some damage indices. Whereas a lot of damage indices have been introduced based on nonlinear dynamic analysis, computational effort, the calculus complicacy and time-consuming of this analysis are the main drawbacks to widespread use of these indices. The objective of this study is to quantify the damage of Shear Wall Reinforced Concrete Frames (SWRCFs) based on pushover analysis as a procedure that can reflect the behavior of structures from elastic to collapse. For this purpose, firstly, several SWRCFs are designed and the capacity spectrum of each one is achieved via pushover analysis. After that, the static damage indices of the designed frames are obtained. Then, nonlinear dynamic analyses are performed on these frames and the Park and Ang damage index as the basis damage criterion is achieved. Afterward, some relations are presented to predict the dynamic damage of these frames via pushover analysis. Eventually, to confirm the validity of the proposed relations, the values of Park and Ang damage index of three new SWRCFs are acquired once utilizing nonlinear dynamic analysis and again applying the introduced relations. Outcomes prove the validity of some presented damage indices.

• Structural Engineering and Mechanics
• /
• v.51 no.4
• /
• pp.531-546
• /
• 2014

In this paper the extension of a recently established energy-based pushover procedure in order to include the higher mode contributions to the seismic response of structures is presented and preliminary evaluated. The steps of the proposed methodology in its new formulation are quite similar to those of the well-known Modal Pushover Analysis. However, the determination of the properties of the 'modal' equivalent single-degree-of-freedom systems is achieved by a rationally founded energy-based concept. Firstly, the theoretical background and the assumptions of the proposed methodology are presented and briefly discussed. Secondly, the sequence of steps to be followed for its implementation along with the necessary equations is systematically presented. The accuracy of the methodology is evaluated by an extensive parametric study which shows that, in general, it provides better results compared to those produced by other similar procedures. In addition, the main shortcoming of the initial version of the methodology now seems to be mitigated to a large extent.

• Structural Engineering and Mechanics
• /
• v.41 no.2
• /
• pp.243-262
• /
• 2012

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

• Structural Engineering and Mechanics
• /
• v.12 no.1
• /
• pp.51-69
• /
• 2001

Whereas the potential of static inelastic analysis methods is recognised in earthquake design and assessment, especially in contrast with elastic analysis under scaled forces, they have inherent shortcomings. In this paper, critical issues in the application of inelastic static (pushover) analysis are discussed and their effect on the obtained results appraised. Areas of possible developments that would render the method more applicable to the prediction of dynamic response are explored. New developments towards a fully adaptive pushover method accounting for spread of inelasticity, geometric nonlinearity, full multi-modal, spectral amplification and period elongation, within a framework of fibre modelling of materials, are discussed and preliminary results are given. These developments lead to static analysis results that are closer than ever to inelastic time-history analysis. It is concluded that there is great scope for improvements of this simple and powerful technique that would increase confidence in its employment as the primary tool for seismic analysis in practice.

• Earthquakes and Structures
• /
• v.14 no.5
• /
• pp.477-492
• /
• 2018

Recently, the adaptive nonlinear static analysis method has been widely used in the field of performance based earthquake engineering. However, the proposed methods are almost deterministic and cannot directly consider the seismic record uncertainties. In the current study an innovative Stochastic Adaptive Pushover Analysis, called "SAPA", based on equivalent hysteresis system responses is developed to consider the earthquake record to record uncertainties. The methodology offers a direct stochastic analysis which estimates the seismic demands of the structure in a probabilistic manner. In this procedure by using a stochastic linearization technique in each step, the equivalent hysteresis system is analyzed and the probabilistic characteristics of the result are obtained by which the lateral force pattern is extracted and the actual structure is pushed. To compare the results, three different types of analysis have been considered; conventional pushover methods, incremental dynamic analysis, IDA, and the SAPA method. The result shows an admirable accuracy in predicting the structure responses.

• Structural Monitoring and Maintenance
• /
• v.5 no.2
• /
• pp.173-187
• /
• 2018

Performance evaluation of RC frame building by nonlinear static pushover analysis that accounts for elastic and post elastic behavior is becoming very popular as a valid decision making tool in seismic hazard resistant designs. Available literature suggests great amount of interest has shown by researchers in suggesting refinements to geometric and material modelling to bridge the gap between analytical predictions and observed performances. Notwithstanding the attempts gaps still exists. Sequence of plastic hinge formation which has great influence on pushover analysis results is an area less investigated. This paper attempts to highlight the importance of hinge sequence considerations to make analysis results more meaningful. Variation in analysis results due to different hinge sequences have been quantified, compared and bounds on analysis results have been presented.

• Journal of Korean Association for Spatial Structures
• /
• v.5 no.1 s.15
• /
• pp.99-105
• /
• 2005

The pushover analysis is becoming a popular tool for seismic design of building structures. In this paper the state-of-art on static nonlinear analysis of building structures is presented with the emphasis on the effects of analysis parameters; i. e., lateral load patterns, modeling of members, and analysis computer programs. The analysed results may have variation even if a same structure is analysed. This paper is to investigate how large the variation is and what the main causes of the variation are. The difference of analysed results, the resultant variation of lateral story shear force and flexural strength of structural members are discussed. The pushover analysis procedure are routinely used in the seismic design of building structures, but some problems must yet be clarified, such as the effects to evaluate the parameters of analysis on the basis of a lateral load patterns and modeling of members.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2004.05a
• /
• pp.103-110
• /
• 2004

The pushover analysis is becoming a popular tool for seismic design of building structures. In this paper the state-of-art on static nonlinear analysis of building structures is presented with the emphasis on the effects of analysis parameters; i. e., lateral load patterns, modeling of members, and analysis computer programs. The analysed results may have variation even if a same structure is analysed. This paper is to investigate how large the variation is and what the main causes of the variation are. The difference of analysed results, the resultant variation of lateral story shear force and flexural strength of structural members are discussed. The pushover analysis procedure are routinely used in the seismic design of building structures, but some problems must yet be clarified, such as the effects to evaluate the parameters of analysis on the basis of a lateral load patterns and modeling of members.

• Journal of Industrial Technology
• /
• v.25 no.A
• /
• pp.15-22
• /
• 2005

In order to evaluate seismic performance of multi-degree-of-freedom bridge structure, moderate lateral load distribution methods using the pushover analysis were developed by many researchers. One of important variables to improve an accuracy of pushover analysis is lateral load distribution. In this study, pushover analyses were performed using the five types of lateral load distribution and seismic performances were evaluated by capacity spectrum method (CSM). To verify an accuracy of suggested lateral load distribution, the maximum displacement estimates by the CSM were compared to those by inelastic time history analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.10a
• /
• pp.209-216
• /
• 2003

The purpose of this study is to investigate the response characteristics of pushover analysis of upper wall-lower frame system with X and Y-directions' lateral load Pushover analysis estimates initial elastic stiffness, post-yielding stiffness, and plastic hinges on each story of structures through three-dimensional nonlinear analysis program. The conclusions of this study are as follows; (1) As a result of pushover analysis, the magnitude of nonlinear response and distribution of yield hinge in lower structure are similar with both X and Y directions, but not in upper structure because of different relative stiffness. (2) The maximum drift ratio of roof is larger for X-direction than for Y-direction with respect to magnitude of shear wall areas in upper structure.