scholarly journals Seismic Vulnerability Assessment of Hybrid Mold Transformer Based on Dynamic Analyses

2019 ◽  
Vol 9 (15) ◽  
pp. 3180
Author(s):  
Ngoc Hieu Dinh ◽  
Joo-Young Kim ◽  
Seung-Jae Lee ◽  
Kyoung-Kyu Choi
Keyword(s):  
Analytical Model ◽  
Degrees Of Freedom ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Shaking Table ◽  
Exceedance Probability ◽  
Shaking Table Tests ◽  
Performance Levels ◽  
Analytical Results ◽  
Dynamic Analyses

In the present study, the seismic vulnerability of a hybrid mold transformer was investigated using a dynamic analytical approach incorporating the experimental results of shaking table tests. The analytical model consisted of linear springs and plastic beam elements, and it has six degrees of freedom simulating the hybrid mold transformer. The dynamic characteristics of the analytical model were determined based on the shaking table tests. The reliability of the analytical model was verified by comparing the test results and analytical results. In order to assess the seismic vulnerability, three critical damage states observed during the shaking table tests were investigated by incorporating the three performance levels specified in ASCE 41-17. Comprehensive dynamic analyses were performed with a set of twenty earthquakes in consideration of the variation of the uncertain parameters (such as the effective stiffness and coil mass) of the mold transformer. Based on the analytical results, fragility curves were established to predict the specified exceedance probability of the mold transformer according to the performance levels.

Seismic Fragility Analysis of Hill Buildings with Uneven Ground Column Heights

2014 ◽  
Vol 638-640 ◽  
pp. 1848-1853
Author(s):  
Lin Qing Huang ◽  
Li Ping Wang ◽  
Chao Lie Ning
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Slope Angle ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Considerable Influence ◽  
Analysis Method ◽  
Ground Acceleration ◽  
Mountainous Regions ◽  
The Hill

The hill buildings sited on slopes have been widely constructed in mountainous regions. In order to estimate the seismic vulnerability of the hill buildings with uneven ground column heights under the effect of potential earthquakes, the exceedance probabilities of the hill buildings sited on different angle slopes in peak ground acceleration (PGA) are calculated and compared by using the incremental dynamic analysis method. The fragility curves show the slope angle has considerable influence on the seismic performance. Specifically, the exceedance probability increases with the increasing of the slope angle at the same performance level.

Improved time-dependent seismic fragility estimates for deteriorating RC bridge substructures exposed to chloride attack

2020 ◽  
pp. 136943322095681
Author(s):  
Fengkun Cui ◽  
Huihui Li ◽  
Xu Dong ◽  
Baoqun Wang ◽  
Jin Li ◽  
...  
Keyword(s):  
Service Life ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Back Propagation ◽  
Steel Corrosion ◽  
Time Dependent ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Seismic Capacity ◽  
Bridge Substructures

RC bridge substructures exposed to chloride environments inevitably suffer from corrosion of reinforcement embodied in concrete. This deterioration issue leads to the loss of reinforcement areas and a reduction in seismic capacity of reinforced concrete (RC) bridge substructures. To quantify the effect of steel corrosion on seismic fragility estimates, this paper proposes an improved time-dependent seismic fragility framework by taking into account the increase in the corrosion rate after concrete cracking and the reduction in seismic capacity of RC bridge substructures during the service life. Additionally, an analytical method based on a back propagation artificial neural network (BP-ANN) is proposed to provide probabilistic capacity estimates of deteriorating RC substructures. A three-span T-shaped girder bridge is selected as a case study bridge to provide improved time-dependent seismic fragility estimates that consider uncertainties in the material properties, geometric parameters, deterioration process and ground motions. The obtained fragility curves show that there is a nonlinear increase in the exceedance probability of deteriorating RC bridge substructures for different damage states during the service life. In addition, time-dependent seismic fragility analysis shows that the cases of considering only the effect of an increase in seismic demand or the reduction in seismic capacity as well as neither of them may lead to a significant underestimation of the seismic vulnerability of deteriorating RC bridge substructures.

scholarly journals Impact of Wall Configurations on Seismic Fragility of Steel-Sheathed Cold-Formed Steel-Framed Buildings

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Liqiang Jiang ◽  
Jihong Ye
Keyword(s):  
Fragility Curves ◽  
Shaking Table ◽  
Seismic Fragility ◽  
Shaking Table Tests ◽  
Cold Formed Steel ◽  
Analytic Models

Seismic fragility of steel-sheathed cold-formed steel-framed (CFSF) structures is scarcely investigated; thus, the information for estimation of seismic losses of the steel-sheathed CFSF buildings is insufficient. This study aims to investigate the seismic fragility of steel-sheathed CFSF buildings with different wall configurations. Analytic models for four 2-story steel-sheathed CFSF buildings are established based on shaking table tests on steel-sheathed CFS walls. Then, a group of fragility curves for these buildings are generated. The results show that the thickness of steel sheathing and the fastener spacing of the wall have significant impact on seismic fragility of steel-sheathed CFSF buildings. The seismic fragility of the CFSF building can be reduced by increasing the thickness of steel sheathing or decreasing the fastener spacing. By increasing the thickness of steel sheathing, the reduction on probability is more obvious for the CP limit. It is also found that the exceeding probability is approximately linear with fastener spacing, with a slope in the range from 0.25%/mm to 0.50%/mm.

Performance-Based Seismic Vulnerability Evaluation of Masonry Buildings Using Applied Element Method in a Nonlinear Dynamic-Based Analytical Procedure

2013 ◽  
Vol 29 (2) ◽  
pp. 399-426 ◽  
Author(s):  
Amin Karbassi ◽  
Marie-José Nollet
Keyword(s):  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Progressive Collapse ◽  
Incremental Dynamic Analysis ◽  
Masonry Building ◽  
Performance Levels ◽  
Plane Failure ◽  
Applied Element Method ◽  
Element Method

A thorough four-step performance-based seismic evaluation for a six-story unreinforced masonry building is conducted. Incremental dynamic analysis is carried out using the applied element method to take advantage of its ability to simulate progressive collapse of the masonry structure including out-of-plane failure of the walls. The distribution of the structural responses and inters-tory drifts from the incremental dynamic analysis curves are used to develop both spectral-based (Sa) and displacement-based (interstory drift) fragility curves at three structural performance levels. The curves resulting from three-dimensional (3-D) analyses using unidirectional ground motions are combined using the weakest link theory to propose combined fragility curves. Finally, the mean annual frequencies of exceeding the three performance levels are calculated using the spectral acceleration values at four probability levels 2%, 5%, 10%, and 40% in 50 years. The method is shown to be useful for seismic vulnerability evaluations in regions where little observed damage data exists.

Shaking table tests of a single-span freestanding rocking bridge for seismic resilience and isolation

2019 ◽  
Vol 22 (15) ◽  
pp. 3222-3233
Author(s):  
Xiu-Li Du ◽  
Yu-Long Zhou ◽  
Qiang Han ◽  
Zhen-Lei Jia
Keyword(s):  
Experimental Study ◽  
Analytical Model ◽  
Seismic Behavior ◽  
Experimental Results ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Peak Displacement ◽  
Bridge Model ◽  
Earthquake Resilience ◽  
Seismic Resilience

Rocking philosophy has advantages to maintain a preferable post-earthquake serviceability as an alternative of seismic resistant systems. This article presents an experimental study on the seismic behavior of a rocking bridge with freestanding columns capped with a freely supported deck. A 1/10 scaled, single-span double-column freestanding bridge was constructed and tested on a shaking table. The experimental results showed that the bridge model could undergo large rocking with enough stability under earthquakes and presented excellent post-earthquake resilience after earthquakes with limited damage and negligible residual displacement. The rocking bridge model also exhibited expected isolation efficiency, which increases as the level of excitations becomes more severe. In addition, an analytical model based on multi-block rocking mechanisms was used to calculate the displacement response. Compared with the experimental results, this analytical model well predicts the peak displacement of the rocking bridge model.

The Shaking Table Test and Analysis of Seismic Performance for Brick Mixes Structures of Traditional Folk Dwelling

2012 ◽  
Vol 166-169 ◽  
pp. 2412-2418
Author(s):  
Chun Hui Li ◽  
Hong Quan Li ◽  
Jin Bao Ji ◽  
Yang Qiang Fu ◽  
Fang Fang Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Seismic Vulnerability ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Seismic Excitation ◽  
Model Structure ◽  
Shaking Table Tests ◽  
Element Analysis ◽  
Reduced Scale

we carried out shaking table tests for 2 layers of a residential brick structure with 1/2 reduced-scale. At the same time, the model structure is studied by finite element analysis with ANSYS. The dynamic response of structure under different seismic excitation and cracking destruction rules were compared and analyzed, seismic vulnerability for the type of brick mixes structures were summarized.. At end, in the light of this type of structure we give the suggestions and measures of aseismatic reinforcement.

scholarly journals Seismic Fragility Assessment of an Isolated Multipylon Cable-Stayed Bridge Using Shaking Table Tests

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Yutao Pang
Keyword(s):  
Fragility Curves ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Shaking Table ◽  
Seismic Fragility ◽  
Shaking Table Tests ◽  
Three Dimensional Model ◽  
Cable Stayed Bridge ◽  
High Flexibility ◽  
Cable Stayed Bridges

In recent decades, cable-stayed bridges have been widely built around the world due to the appealing aesthetics and efficient and fast mode of construction. Numerous studies have concluded that the cable-stayed bridges are sensitive to earthquakes because they possess low damping characteristics and high flexibility. Moreover, cable-stayed bridges need to warrant operability especially in the moderate-to-severe earthquakes. The provisions implemented in the seismic codes allow obtaining adequate seismic performance for the cable-stayed bridge components; nevertheless, they do not provide definite yet reliable rules to protect the bridge. To date, very few experimental tests have been carried out on the seismic fragility analysis of cable-stayed bridges which is the basis of performance-based analyses. The present paper is aimed at proposing a method to derive the seismic fragility curves of multipylon cable-stayed bridge through shake table tests. Toward this aim, a 1/20 scale three-dimensional model of a 22.5 m cable-stayed bridge in China is constructed and tested dynamically by using the shaking table facility of Tongji University. The cable-stayed bridge contains three pylons and one side pier. The outcomes of the comprehensive shaking table tests carried out on cable-stayed bridge have been utilized to derive fragility curves based on a systemic approach.

scholarly journals Assessment of Seismic Vulnerability of Steel and RC Moment Buildings Using HAZUS and Statistical Methodologies

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Iman Mansouri ◽  
Jong Wan Hu ◽  
Kazem Shakeri ◽  
Shahrokh Shahbazi ◽  
Bahareh Nouri
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Moment Frames ◽  
Limit States ◽  
Rc Frames ◽  
Dynamic Analyses ◽  
Damage States ◽  
Definition Of ◽  
Nonlinear Dynamic Analyses

Designer engineers have always the serious challenge regarding the choice of the kind of structures to use in the areas with significant seismic activities. Development of fragility curve provides an opportunity for designers to select a structure that will have the least fragility. This paper presents an investigation into the seismic vulnerability of both steel and reinforced concrete (RC) moment frames using fragility curves obtained by HAZUS and statistical methodologies. Fragility curves are employed for several probability parameters. Fragility curves are used to assess several probability parameters. Furthermore, it examines whether the probability of the exceedence of the damage limit state is reduced as expected. Nonlinear dynamic analyses of five-, eight-, and twelve-story frames are carried out using Perform 3D. The definition of damage states is based on the descriptions provided by HAZUS, which gives the limit states and the associated interstory drift limits for structures. The fragility curves show that the HAZUS procedure reduces probability of damage, and this reduction is higher for RC frames. Generally, the RC frames have higher fragility compared to steel frames.

Geometric Configuration Effects on Nonlinear Seismic Behavior of Concrete Gravity Dam

2018 ◽  
Vol 12 (01) ◽  
pp. 1850003 ◽  
Author(s):  
Md. Imteyaz Ansari ◽  
Mohd Saqib ◽  
Pankaj Agarwal
Keyword(s):  
Nonlinear Dynamic ◽  
Seismic Behavior ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Geometric Configuration ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Dynamic Analyses

The effects of geometric configuration on the seismic vulnerability of concrete gravity dam are discussed in the present study. The seismic vulnerability of concrete gravity dams has been represented through fragility curves obtained through incremental dynamic analyses by considering their nonlinear dynamic behavior. Five different geometries of concrete gravity dams are considered and fragility analyses are carried out on the basis of Incremental Dynamic Analyses. The effect of smoothening of re-entrant corners in the geometry of high concrete gravity dam is also presented as a possible solution.

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