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 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.

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 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 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 The Effect of Long Duration Earthquakes on the Overall Seismic Behavior of Steel Structures Designed According to Eurocode 8 Provisions

Vibration ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 464-477
Author(s):  
Panagiota Katsimpini ◽  
Foteini Konstandakopoulou ◽  
George A. Papagiannopoulos ◽  
Nikos Pnevmatikos ◽  
George D. Hatzigeorgiou
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Steel Structures ◽  
Eurocode 8 ◽  
Steel Buildings ◽  
Long Duration ◽  
Base Steel ◽  
Fixed Base ◽  
Permanent Settlement ◽  
Nonlinear Time History

Premature and simultaneous buckling of several steel braces in steel structures due to the prolonged duration of a seismic motion is one of the issues that must be addressed in the next version of Eurocode 8. In an effort to contribute towards the improvement of the seismic design provisions of Eurocode 8, an evaluation of the overall behavior of some steel building-foundation systems under the action of long duration seismic motions is performed herein by means of nonlinear time-history seismic analyses, taking into account soil–structure interaction (SSI) effects. In particular, the maximum seismic response results—in terms of permanent interstorey drifts, overturning moments and base shears of the steel buildings as well as of the permanent settlement and tilting of their foundations—are computed. It is found that the seismic performance of steel buildings when subjected to long duration seismic motions is: (i) acceptable for the two and five-storey fixed base steel buildings and for the two-storey steel buildings with SSI effects included; (ii) unacceptable for the eight-storey fixed base steel buildings and for the five and eight-storey steel buildings with SSI effects included. In all cases of steel buildings with SSI effects included, the seismic performance of the mat foundation, as expressed by the computed values of residual settlement and tilting, is always acceptable.

Development of improved inelastic displacement prediction equations for the seismic design of hybrid systems

2012 ◽  
Vol 45 (1) ◽  
pp. 1-14 ◽  
Author(s):  
J.L. Ceballos C. ◽  
T.J. Sullivan
Keyword(s):  
New Zealand ◽  
Hybrid Systems ◽  
Linear Time ◽  
Time History ◽  
Systems Design ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Seismic Displacement ◽  
Inelastic Displacement ◽  
Displacement Based

The use of hybrid joints to provide pre-cast concrete and timber structures with ductile response and self-centering capability is becoming increasingly popular in New Zealand, as is evident by the increasing number of building solutions that incorporate the technology as well as the design provisions for hybrid systems currently included in the New Zealand Concrete standard. This paper raises some issues with the current code approach to estimate the inelastic seismic displacement demand on hybrid systems. The work then presents the results of a series of non-linear time history analyses of single degree of freedom (SDOF) systems characterised by the flag-shaped hysteretic rule, in order to identify a general, improved expression for the equivalent viscous damping of hybrid systems. The new equivalent viscous damping expression is expected to provide more reliable control of inelastic displacement demands for hybrid systems design used Displacement-Based Design (DBD) procedures. In addition, the last part of the paper also discusses how the findings in the paper could be utilised to provide improved control of displacement demands when hybrid systems are designed using force-based procedures.

Study on normalization of residual displacements for single-degree-of-freedom systems

2021 ◽  
pp. 875529302098801
Author(s):  
Zhibin Feng ◽  
Jinxin Gong
Keyword(s):  
Structural Characteristics ◽  
Permanent Deformation ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Intermediate Step ◽  
Residual Displacement ◽  
Inelastic Displacement ◽  
Residual Displacements ◽  
Constant Strength ◽  
Nonlinear Time History

Residual displacement spectrum is one of the most important means to predict the permanent deformation of structures after the earthquake, and various normalizations of residual displacements have generally been used for construction of the spectrum. However, the issue regarding the merits and drawbacks of each normalization has not yet been investigated thoroughly. A comparison between two normalizations that relate the residual displacements to the elastic and inelastic displacements is made in terms of the effect of ground motion and structural characteristics by means of the results of nonlinear time history analysis. The statistical results reveal that the residual-to-peak-inelastic displacement ratios have the advantages of small dispersion, samples without any outliers, and relatively symmetric distribution, which benefits from the strong correlation between residual and peak inelastic displacements. Moreover, the residual-to-peak-inelastic displacement ratios are almost independent of site conditions, significant duration, and natural periods. Consequently, the peak inelastic displacements are superior to the elastic ones as an intermediate step for residual displacements estimation, provided that the peak inelastic displacements are estimated with a low uncertainty. For providing alternatives to estimate residual displacement demands, the constant-strength residual displacement spectra are developed for both normalizations.

The Analysis of Non-Linear Seismic Response of an Infilled Frame Structure in Yingxiu Town – The Heavy Disaster Areas of Wenchuan 8.0 Earthquake

2009 ◽  
Vol 417-418 ◽  
pp. 777-780
Author(s):  
Pei Lei Yan ◽  
Bai Tao Sun ◽  
Hong Fu Chen
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Frame Structure ◽  
Nonlinear Static Analysis ◽  
Analysis Model ◽  
Infill Wall ◽  
Infilled Frame ◽  
History Analysis ◽  
Complex Building ◽  
Nonlinear Static

On 12 May 2008, a magnitude 8.0 earthquake happened in Wenchuan, China .It was the most serious earthquake in china since 1949, causing very huge casualties and engineering damages. The complex building of the Xuankou secondary school in Yingxiu town was designed by the Code for Seismic Design of Buildings of China (GB50011-2001), the seismic fortification intensity of the buildings was 7 degree. In the earthquake, it was destroyed most seriously, and the engineering damage was characteristic. In the paper, the property of material nonlinearity was considered ,the nonlinear analysis model of infilled frame structure was established, the time history analysis and nonlinear static analysis were used during inelastic stage, the main cause of structural destruction was obtained, the influence of the infill wall on the structure was discussed.Therefore ,the results can provide valuable reference for the seismic design of infilled frame structure.

Nonlinear Finite Element Analysis of Unreinforced Masonry Walls

2016 ◽  
Vol 857 ◽  
pp. 142-147
Author(s):  
S. Thomas Feba ◽  
Bennet Kuriakose
Keyword(s):  
Numerical Model ◽  
Unreinforced Masonry ◽  
Masonry Wall ◽  
Seismic Retrofitting ◽  
Nonlinear Static Analysis ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Element Analysis ◽  
Historical Masonry ◽  
Nonlinear Static

Most of the monumental structures worldwide and residential structures in developing countries are built in masonry. The studies performed by various researchers prove the vulnerability of masonry structures under various circumstances, especially under earthquakes, so as to necessitate detailed contemplation. In this paper, a numerical model for nonlinear static analysis of unreinforced masonry walls is developed based on a macro-modelling approach. A detailed parametric study is also performed to analyse the effect of wall thickness as well as length on the behaviour of the masonry wall. The present numerical model can be utilized for risk assessment and seismic retrofitting of historical masonry structures.

scholarly journals The necessity of transverse steel reinforcement for confinement in structural reinforced concrete walls using nonlinear static and dynamic analysis method

2020 ◽  
Vol 18 (2) ◽  
pp. 161-175
Author(s):  
Eisa Mohammad ◽  
Eisa Mohammad
Keyword(s):  
Reinforced Concrete ◽  
Time History ◽  
Nonlinear Static Analysis ◽  
Concrete Walls ◽  
Static And Dynamic Analysis ◽  
Concrete Members ◽  
Reinforced Concrete Walls ◽  
Steel Bars ◽  
Nonlinear Static ◽  
Transverse Steel

Reinforced concrete walls are one of the most efficient and earthquake-resistant systems. In order to provide adequate performance against seismic forces, their ductility should be provided by considering some design principles. Since confining the concrete increases the ductility of the reinforced concrete members, design instructions try to increase the ductility of the wall by utilizing transverse rebars in a certain length of wall edges. In this study, the need for the transverse steel bars to apply confinement in concrete is compared with the equations suggested by previous studies for the displacement-based design of structural bearing walls. For this purpose, nonlinear static analysis and time history analysis was utilized. The results of the study indicate that the lateral deformation of the structural bearing walls is less than the final limit specified by the design codes, even without considering the transverse steel bars for concrete confinement.

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