scholarly journals A look into uncertainty in structural seismic performance arising from additional Rayleigh damping in inelastic time history analysis

2014 ◽  
pp. 1633-1640
Author(s):  
P Jehel
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Time History Analysis ◽  
Rayleigh Damping ◽  
History Analysis

Seismic Performance Analysis of Tower Lines System under Multiple Support Excitation

2013 ◽  
Vol 732-733 ◽  
pp. 1085-1089
Author(s):  
Jian Mei Sun ◽  
Jun Qiang Li ◽  
Fu Gang Yang
Keyword(s):  
Seismic Response ◽  
Seismic Performance ◽  
Time History ◽  
Time History Analysis ◽  
Transmission Tower ◽  
Long Span ◽  
History Analysis ◽  
Tower Structure ◽  
Multiple Support ◽  
Support Excitation

In order to determine the calculational model of long span transmission tower structure under the multiple support excitation, tower-lines system are adopted. Seismic Performance of long span transmission tower lines system under Multiple Support Excitation were studied by time history analysis method. The seismic response difference of two kinds of excitation is analyzed from Dynamic Characteristics and the number of dangerous bar. It will offer the theory data for the seismic design of the kind of structure. Through analysis, the seismic response difference of the two kinds excitation is correlative to the apparent velocity; Therefore long span transmission tower structure should be considered the effect of multiple support excitation, otherwise the conclusion will be inclined to conservative or risk. Key words: tower lines system; seismic response; time history analysis,multiple support excitation

Vertical seismic response analysis of long-span composite open-web grid floor

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qizhu Yang ◽  
Kejian Ma ◽  
Huagang Zhang ◽  
Yanhui Wei ◽  
Ze Xiang
Keyword(s):  
Seismic Performance ◽  
Response Spectrum ◽  
Time History ◽  
Grid Floor ◽  
Time History Analysis ◽  
Analysis Method ◽  
Response Spectrum Method ◽  
Content Type ◽  
Spectrum Method ◽  
History Analysis

PurposeThe purpose of this paper is to study the dynamic characteristics and seismic performance of the composite open-web grid floor structure.Design/methodology/approachStudied by using mode-superposition response spectrum method and time history analysis method.FindingsThe results show that the vertical mode-superposition response spectrum method is close to the time history analysis method. The floor has strong seismic performance, and the deflection and internal force are not large under vertical seism. The vertical seismic action suggested that 10% of the representative value of gravity load should be used to ensure the safety of the structure.Originality/valueIn the design, the mid-span section should be properly strengthened or the variable section design should be adopted.

scholarly journals Seismic Performance Evaluation of a Reinforced Concrete Arch Bridge

2017 ◽  
Vol 12 (1) ◽  
pp. 120-126
Author(s):  
Jeena Dangol ◽  
Rajan Suwal
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Seismic Performance ◽  
Axial Force ◽  
Time History ◽  
Time History Analysis ◽  
Longitudinal Displacement ◽  
Arch Bridge ◽  
History Analysis ◽  
Force Variation

The entire Himalayan belt including Nepal area, because of its active tectonic movement, is seismically active causing high risk of earthquake in this region. It is important to evaluate the seismic performance of the structures including bridges to identify to what extent they would survive during earthquake. A reinforced concrete two hinged arch bridge located in Chobhar, Nepal has been selected for the research purpose. This paper presents the determination of seismic performance of a reinforced concrete arch bridge under different ground motions. The seismic input was taken as five different earthquake ground motion histories having different V/H peak ground acceleration ratio for time history analysis. Displacement capacity of the bridge was determined from pushover analysis. Time history analysis was conducted in two different steps: first only horizontal acceleration was applied and next vertical acceleration was applied in addition to horizontal ground motion. Comparisons were made between the responses of the bridge for these two cases. It was found that inclusion of vertical component of ground motion has negligible effect in variation of longitudinal displacement. However, there was remarkable effect in axial force variation. Significant effect in axial force variation in arch rib was observed as V/H ratio increased although the effect in longitudinal displacement with increase in V/H ratio was negligible. Moment demand also increased due to high axial force variation because of vertical ground motion.Journal of the Institute of Engineering, 2016, 12(1): 120-126

Time-History Analysis of Seismic Performance of Metro Station by Top-Down Boring with Cast-In Situ Arch

2012 ◽  
Vol 256-259 ◽  
pp. 2216-2221 ◽  
Author(s):  
De Yun Ding ◽  
Wei Feng Wang ◽  
Mei Qun Huang ◽  
Xiu Ren Yang ◽  
Zong Zhen Wu
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Time History Analysis ◽  
Top Down ◽  
Metro Station ◽  
Main Structure ◽  
History Analysis ◽  
Earthquake Action ◽  
Rare Earthquake

Taken the Dawanglu station of Beijing metro line 14 as engineering background, the seismic performance of metro station by top-down boring with cast-in-situ arch under rare earthquake action (E3) is researched. A three-dimensional dynamic model is established by using the finite element program MIDAS/GTS. Through the time-history analysis method, the displacement response of the main structure of metro station is obtained. The storey relative displacement and storey drift angle of the main structure are mainly analyzed. Numerical results show that under rare earthquake action, metro station structure can satisfy the requirements of the seismic performance, and can be regarded as a valuable reference for the design.

scholarly journals Analysis on the Influence of Increasing Seismic Fortification Intensity on Seismic Performance of Underground Station

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Ying Zeng ◽  
Shiguang Xu ◽  
Shiqian Yin
Keyword(s):  
Ground Motion ◽  
Seismic Performance ◽  
Time History ◽  
Time History Analysis ◽  
Structural Deformation ◽  
Equivalent Linearization ◽  
History Analysis ◽  
Underground Station ◽  
The Impact ◽  
Station Structure

China Earthquake Parameter Zoning (2016) has increased the seismic fortification intensity in Chengdu from VII to VIII. It is necessary to conduct in-depth discussion on the impact of the seismic performance of the built underground station structure. In this paper, a stratum-structure finite element model is established with a Chengdu subway station as an example. The model boundary adopts viscoelastic boundary, and the ground motion is input in the form of equivalent nodal force. The equivalent linearization method is used to consider the nonlinearity of soil materials. The time-history analysis of seismic fortification intensity of VII and VIII degrees is carried out, respectively. By comparing the calculation results of the two seismic fortification intensity ground motion conditions, it is concluded that the connection between the side wall and the floor is the weakest position of the station structure under the action of the earthquake; the seismic fortification intensity is increased from VII to VIII to the internal force of the structure. It has a relatively large impact, especially the most obvious impact on the bending moment. The results of the verification of the seismic time-history analysis show that the increase of fortification intensity will have a more obvious impact on the structural deformation, and the structural design of the station can meet the safety performance requirements of VII and VIII degrees of seismic fortification. The research has certain reference significance for the seismic safety evaluation of the built underground station structure in Chengdu area.

Influence Factors and Repair Effects of Seismic Damage to a Box Section Steel Pier

2019 ◽  
Vol 13 (03n04) ◽  
pp. 1940001
Author(s):  
Zhongqiu Fu ◽  
Dongyang Wu ◽  
Liang Fang ◽  
Donghua Chen ◽  
Bohai Ji
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Performance ◽  
Nonlinear Dynamic ◽  
Time History ◽  
Time History Analysis ◽  
Steel Plates ◽  
Box Section ◽  
History Analysis ◽  
Dynamic Time

The seismic performance of a steel pier of box section was studied through low-cycle cyclic testing. The damaged specimens were repaired by filling with concrete and welding steel plates. The low-cycle cyclic test was then repeated. The effects of repairs were investigated by comparison of failure mode, energy dissipation performance, and ductility before and after repair. To supplement the data, the influence of different factors on the seismic bearing capacity and ductility of steel piers were analyzed by finite element method. The repair effects were compared by threshold of the displacement from the experiment. Based on the displacement angle response of the nonlinear dynamic time history analysis, the seismic performance is checked. The results show that repair had favourable effects on the damaged specimens. The horizontal bearing capacity and ductility of the specimens filled with concrete are significantly enhanced. Reinforcement by steel plates can increase the ductility and cumulative energy dissipation of the steel pier. An axial compression ratio of 0.2 and a concrete filling ratio of 30% are suggested. The horizontal bearing capacity can be improved by increasing the steel strength while the concrete strength shows little effect. The angular displacement from nonlinear dynamic time-history analysis was less than the test threshold, so the existing methods used for seismic performance verification are safe.

scholarly journals Material Damping in Dynamic Analysis of Structures (With LIRA-SAPR Program)

2020 ◽  
Vol 16 (1) ◽  
pp. 63-70
Author(s):  
Mariia Barabash ◽  
Bogdan Pisarevskyi ◽  
Yaroslav Bashynskyi
Keyword(s):  
Numerical Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Viscous Damping ◽  
Material Damping ◽  
Seismic Safety ◽  
Damping Coefficients ◽  
Damping Effect ◽  
Rayleigh Damping ◽  
History Analysis

AbstractThe purpose of this paper is to justify that it is necessary to take account of physical and mechanical properties of soil and different materials of erected structure for damping vibrations in dynamic loads; to suggest tools for modelling the damping effect (natural or engineering induced) between foundation and soil. Certain technique is suggested for modelling behaviour of structure in time history analysis with account of material damping. In the software, the damping effect is modelled in two variants: Rayleigh damping (for structure) and finite element of viscous damping. When solving this problem, the following results were obtained: physical meaning of material damping is described; Rayleigh damping coefficients were computed through modal damping coefficients. Numerical analysis is carried out for the structure together with soil in earthquake load using developed FE of viscous damping. Time history analysis was carried out for the problem. Peak values of displacement, speed and acceleration at the floor levels were compared. Analysis results are compared (with and without account of material damping). Significant influence of damping on the stress-strain state of the structure is confirmed. Scientific novelty of the paper is in the following: the damping effect is proved to happen regardless of the presence of installed structural damping equipment; technique for account of damping with Rayleigh damping coefficients is developed; new damping element is developed – FE of viscous damping (FE 62), its behaviour is described as linear mathematical model. Practical implications of the paper: developed technique and new FE enables the user to carry out numerical analysis properly and work out a set of measures on seismic safety for buildings and structures.

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