scholarly journals Quasistatic Seismic Damage Indicators for RC Structures from Dissipating Energies in Tangential Subspaces

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Wilfried B. Krätzig ◽  
Yuri S. Petryna
Keyword(s):  
Structural Damage ◽  
Low Cycle Fatigue ◽  
Time History ◽  
Seismic Damage ◽  
Rc Structures ◽  
Rc Frames ◽  
Tangential Stiffness ◽  
Damage Indicators ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

This paper applies recent research on structural damage description to earthquake-resistant design concepts. Based on the primary design aim of life safety, this work adopts the necessity of additional protection aims for property, installation, and equipment. This requires the definition of damage indicators, which are able to quantify the arising structural damage. As in present design, it applies nonlinear quasistatic (pushover) concepts due to code provisions as simplified dynamic design tools. Substituting so nonlinear time-history analyses, seismic low-cycle fatigue of RC structures is approximated in similar manner. The treatment will be embedded into a finite element environment, and the tangential stiffness matrixKTin tangential subspaces then is identified as the most general entry for structural damage information. Its spectra of eigenvaluesλior natural frequenciesωiof the structure serve to derive damage indicatorsDi, applicable to quasistatic evaluation of seismic damage. Because detKT=0denotes structural failure, such damage indicators range from virgin situationDi=0to failureDi=1and thus correspond with Femaproposals on performance-based seismic design. Finally, the developed concept is checked by reanalyses of two experimentally investigated RC frames.

Study on the Method of Structural Seismic Performance Evaluation Based on the Damage Spectra

2010 ◽  
Vol 163-167 ◽  
pp. 4324-4330
Author(s):  
Jun Teng ◽  
Hu Bing Tu
Keyword(s):  
Performance Evaluation ◽  
Seismic Performance ◽  
Structural Damage ◽  
Evaluation Method ◽  
Low Cycle Fatigue ◽  
Time History ◽  
Seismic Damage ◽  
Hysteretic Energy ◽  
Seismic Performance Evaluation ◽  
The Impact

Park-Ang seismic damage model is increasingly concerned due to it considers not only maximum elasto-plastic deformation, but also low cycle fatigue accumulated hysteretic energy, while research on the method of seismic performance evaluation based on the model is still rare. Therefore, a new evaluation method on the basis of damage spectra is proposed in this paper. Damage spectra of site I considering three kinds of ultimate deformation ductility factor are built firstly, and then transformation relationship between damage of MDOF and SDOF of frame structures is researched. Lastly, procedure of seismic damage evaluation on the structure is proposed. An example is used to confirm the validity of the spectra-based seismic performance evaluation method. The example analysis shows that: the method proposed here is reasonable to consider the impact of the cumulative hysteretic energy on the structural damage. The results from the method have good consistency with the time history analysis results. It can assess the extent of structural damage from the statistical viewpoint.

Nonlinear Structural Damage Detection Based on Adaptive Volterra Filter Model

2018 ◽  
Vol 18 (02) ◽  
pp. 1871003 ◽  
Author(s):  
J. Prawin ◽  
A. Rama Mohan Rao
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Linear Models ◽  
Time History ◽  
Diagnostic Techniques ◽  
Filter Model ◽  
Volterra Filter ◽  
Damage Indices ◽  
Before And After ◽  
Nonlinear Time History

The majority of the existing damage diagnostic techniques are based on linear models. Changes in the state of the dynamics of these models, before and after damage in the structure based on the vibration measurements, are popularly used as damage indicators. However, the system may initially behave linearly and subsequently exhibit nonlinearity due to the incipience of damage. Breathing cracks that exhibit bilinear behavior are one such example of the damage induced due to nonlinearity. Further many real world structures even in their undamaged state are nonlinear. Hence, in this paper, we present a nonlinear damage detection technique based on the adaptive Volterra filter using the nonlinear time history response. Three damage indices based on the adaptive Volterra filter are proposed and their sensitiveness to damage and noise is assessed through two numerically simulated examples. Numerical investigations demonstrate the effectiveness of the adaptive Volterra filter model to detect damage in nonlinear structures even with measurement noise.

Probabilistic Peak Displacement Analysis of Bridge Structures with P-Δ Effect

2013 ◽  
Vol 405-408 ◽  
pp. 1674-1677
Author(s):  
Bo Yu ◽  
Di Liu ◽  
Lu Feng Yang
Keyword(s):  
Time History ◽  
Dynamic Responses ◽  
Nonlinear Time History Analysis ◽  
Bridge Structure ◽  
Vibration Period ◽  
Peak Displacement ◽  
Sdof System ◽  
Bridge Structures ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

Peak displacement is one of the most important parameters for the performance based seismic design of bridge structure, while the peak displacement is often significantly impacted by the P-Δ effect. In this study, the influence of the P-Δ effect on the statistics of peak displacement of bridge structure was quantificationally investigated based on a series of nonlinear time-history analysis. The bridge structure was idealized as the single degree of freedom (SDOF) system and the hysteretic behaviour was represented by the improved Bouc-Wen model. The statistic analysis was implemented based on the inelastic dynamic responses of the SDOF system under 69 selected earthquake records. The results show that the P-Δ effect has significant impact on the mean and dispersion of peak displacement of bridge structures, especially if the normalized yield strength and the natural vibration period are small.

scholarly journals FRP Composite in Mitigating Seismic Risk of RC Structures in Near-Fault Regions with/without Aftershocks

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Vui Van Cao ◽  
Son Quang Pham
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Damage State ◽  
Rc Structures ◽  
Seismic Sequences ◽  
Near Fault ◽  
Damage Indices ◽  
Aftershock Sequences ◽  
Nonlinear Time History ◽  
Original Frame

The literature related to earthquakes and fibre reinforced polymer (FRP) retrofitting can be divided into two main categories: (1) the applications of FRP to retrofit structures subjected to single traditional earthquakes and (2) the effects of mainshock-aftershock sequences on original structures (without FRP retrofitting). Research on using FRP to mitigate the risk of pulse-type mainshock-aftershock sequences for reinforced concrete (RC) structures located in near-fault regions is hardly found in the literature and is thus the aim of this study. To achieve this aim, a four-storey RC frame, near-fault mainshocks, and seismic sequences were selected. The frame was retrofitted using FRP wraps at plastic hinge locations. Nonlinear time history and damage analyses of the original and FRP-retrofitted frames subjected to these near-fault mainshocks and seismic sequences were conducted. The results showed that aftershocks significantly increase the damage indices of the frames, shifting the damage state of the original frame from severe damage to collapse and the damage state of the FRP-retrofitted frame from light damage to moderate damage. FRP retrofitting successfully reduced the risk of seismic sequences by reducing the damage two levels, shifting the damage state of the original frame from collapse to moderate damage.

Investigation of Damages in RC Frames Under Near Field Earthquakes Using a Damage Index

2016 ◽  
Vol 16 (02) ◽  
pp. 1450094 ◽  
Author(s):  
Seyed Morteza Zinati Yazdi ◽  
Mohammad Taghi Kazemi
Keyword(s):  
Near Field ◽  
Damage Index ◽  
Time History ◽  
General Rule ◽  
Nonlinear Time History Analysis ◽  
Far Field ◽  
Moment Frames ◽  
Moment Frame ◽  
Rc Frames ◽  
Nonlinear Time History

Heavy damages on structures caused by near field earthquakes in recent years has brought serious attention to this problem. An examination of previous records has shown significant differences for near field earthquakes, including a large energy pulse, unlike far field earthquakes. But as a general rule, the effects of near field earthquakes have been ignored in most building codes. The purpose of this paper is to investigate the effect of near field earthquakes on reinforced concrete (RC) moment frames. To achieve this goal, the Erduran damage index, an efficient way to calculate damage, was employed to analyze two 4- and 8-story RC moment frame buildings. The buildings with moderate and high ductility were designed by the strength criteria. Seven pairs of near field and far field earthquakes were scaled and used for dynamic nonlinear time history analysis. Using Erduran’s beam and column damage index, respectively, based on rotation and drift, the results from both near and far field earthquakes were compared. Moreover, for better assessment, 4-story buildings were evaluated from the performance based viewpoint of design. We observe from the results that most of the components of the structures under near field earthquakes sustained severe damages and in some cases even component failure. Components of the structures under near field earthquakes suffered from 30% more of damage, on average, than that under far field earthquakes.

Direct Displacement Procedure for Performance-Based Seismic Design of Mid-Rise Wood-Framed Structures

2009 ◽  
Vol 25 (3) ◽  
pp. 583-605 ◽  
Author(s):  
Wei Chiang Pang ◽  
David V. Rosowsky
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Design Procedure ◽  
Time History ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Framed Structures ◽  
History Analysis ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

This paper presents a direct displacement design (DDD) procedure that can be used for seismic design of multistory wood-framed structures. The proposed procedure is applicable to any pure shear deforming system. The design procedure is a promising design tool for performance-based seismic design since it allows consideration of multiple performance objectives (e.g., damage limitation, safety requirements) without requiring the engineer to perform a complex finite element or nonlinear time-history analysis of the complete structure. A simple procedure based on normalized modal analysis is used to convert the code-specified acceleration response spectrum into a set of interstory drift spectra. These spectra can be used to determine the minimum stiffness required for each floor based on the drift limit requirements. Specific shear walls can then be directly selected from a database of backbone curves. The procedure is illustrated on the design of two three-story ATC-63 archetype buildings, and the results are validated using nonlinear time-history analysis.

An open-source framework for regional earthquake loss estimation using the city-scale nonlinear time history analysis

2020 ◽  
Vol 36 (2) ◽  
pp. 806-831 ◽  
Author(s):  
Xinzheng Lu ◽  
Frank McKenna ◽  
Qingle Cheng ◽  
Zhen Xu ◽  
Xiang Zeng ◽  
...  
Keyword(s):  
Open Source ◽  
Time History ◽  
Seismic Damage ◽  
Scientific Workflow ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
History Analysis ◽  
Loss Prediction ◽  
Nonlinear Time History ◽  
Damage Simulation

Regional seismic damage simulation of buildings provides decision-makers with important information for earthquake disaster prevention and mitigation. Utilizing nonlinear time history analysis using multiple-degree-of-freedom (MDOF) models for buildings, and the next-generation performance-based earthquake engineering, an open-source general-purpose scientific workflow for seismic damage simulation and loss prediction of urban buildings (referred to as SimCenter Workflow) is presented in this study. To introduce the SimCenter Workflow process in detail and demonstrate its advantages, a seismic damage simulation and loss prediction for 1.8 million buildings in the San Francisco Bay Area were performed using the SimCenter Workflow. The open nature and modularization of the SimCenter Workflow facilitate its extensibility and make it practical for researchers to apply to seismic damage simulations in other regions.

Correlation between Damage Indexes in Knee Bracing Frames Subjected to Earthquakes

2011 ◽  
Vol 255-260 ◽  
pp. 2350-2354
Author(s):  
Kamran Faraji ◽  
Mahmoud Miri
Keyword(s):  
Structural Damage ◽  
Steel Frames ◽  
Time History ◽  
Deformation Energy ◽  
Hysteretic Behavior ◽  
Nonlinear Time History Analysis ◽  
Damage Level ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Earthquake Accelerograms

For vulnerability assessment of structures, different damage indexes have been established by researchers that estimate the structural damage level. In these indexes different parameters have been used for calculating structural damage level. In this paper, damage indexes based on deformation, energy and cycle hysteretic behavior are investigated in order to find a correlation between their numerical values. The selected damage indexes are calculated and compared by applying them in nonlinear time history analysis of low and intermediate rise knee braced steel frames subjected to a set of seven earthquake accelerograms. Correlations between various indexes have been presented graphically and approximate conversion formulas are also provided.

DRIFT DEMANDS OF LOW-DUCTILE MOMENT RESISTANCE FRAMES (MRF) UNDER FAR FIELD EARTHQUAKE EXCITATIONS

2016 ◽  
Vol 78 (6) ◽  
Author(s):  
Mohammadreza Vafaei ◽  
Sophia C. Alih ◽  
Qotrunnada Abdul Rahman
Keyword(s):  
Structural Damage ◽  
Load Capacity ◽  
Time History ◽  
Seismic Excitation ◽  
Nonlinear Time History Analysis ◽  
Soft Story ◽  
History Analysis ◽  
The Stability ◽  
Nonlinear Time History ◽  
Strong Ground

Most of current Malaysian’s structures have not been designed with consideration of seismic excitation effect. Tremors that have been recorded locally due to active local faults and earthquake events in neighboring countries have raised the question about the level of safety of these structures.  The effects of seismic excitation on the stability and fragility of the structures are now being concerned by most researchers and engineers in order to mitigate structural damage and societal losses. This study focuses on the seismic performance of Reinforced Concrete (RC) Moment Resistance Frames (MRF) in Malaysia which has been only designed to resist gravity and wind loads effects. An ordinary building layout with different number of stories (four, seven, and 10 stories) is selected in a way that can represent the potential of soft-story phenomenon in RC buildings in Malaysia. Such structures have limited lateral load capacity to withstand against strong ground motion. Nonlinear time history analysis is used to analyze the structures using seven different ground motions scaled to 0.05g, 0.1g and 0.15g to suit Malaysian condition. The outcomes of this study illustrate the vulnerability of the typical RC, MRF structures in Malaysia to soft-story phenomenon and clarify on the necessity of seismic retrofit for such structures.  

Seismic Reliability Analysis of Structural Systems

2009 ◽  
Author(s):  
Paata Rekvava
Keyword(s):  
Three Dimensional ◽  
Design Procedure ◽  
Time History ◽  
Reliability Function ◽  
Nonlinear Time History Analysis ◽  
Structural Systems ◽  
Rc Buildings ◽  
Seismic Reliability ◽  
Performance Based Seismic Design ◽  
Nonlinear Time History

A method is presented for the evaluation of the seismic reliability function of realistic structural systems. The method is based on a preliminary simulation involving three-dimensional nonlinear time history analysis of the soil-interface-building system. The design procedure is performed to establish the probabilistic characterization of the demands on the structure, followed by the solution of system reliability problem with correlated demands and capacities. The Structural behavior is evaluated by means of the methodology of Performance-Based Seismic Design (PBSD). This study has taken into account the stochastic nature of the spatial ground motion in Tbilisi region. The method is demonstrated with an application to a 3D RC Buildings subjected to seismic excitation for the specified hazard at the site. The developed method and obtained results can be used in seismic risk study for new buildings of examined type under design, as well as for existing RC buildings of old generation for future seismic activity.

Sign in / Sign up

Export Citation Format

Share Document