Comparative Study on Seismic Response Analysis Methods of Spherical Tanks

Author(s):  
Zhongming Ma ◽  
Guang Xiao ◽  
Minghui Zhang ◽  
Haijun Zhang ◽  
Ruixue Du

Abstract Spherical tank is an important storage equipment in petrochemical industry. It is often used to store inflammable and explosive materials. Once it is damaged in the earthquake, it will lead to serious consequences. In this paper, the finite element model of spherical tank is established by ANSYS software. The bottom shear method, mode decomposition method and time history analysis method are used to calculate the strength of spherical tank. The weakest link of the structure under the real earthquake load is determined, which provides the basis for the seismic safety guarantee and structural design of spherical tank. The applicability of the three calculation methods is compared and discussed.

Author(s):  
Zhirong Yang ◽  
Dayong Zhang ◽  
Longwei Guo ◽  
Baibing Yang ◽  
Guodong Wang

The seismic safety problem of the spherical tank under seismic load has become one important subject in seismic research of special equipment. Based on the ANSYS finite element software, typical spherical tank mechanics model is established first of all, through precise time history response analysis under the seismic excitation to determine the significant location of the stress. Then, the seismic performance impact of the support structure design parameters is analyzed. Finally, the seismic performance of all kinds of spherical tank, such as the large, medium and small tank, is determined. This paper provides a reasonable basis for the anti-seismic safety security and design of the spherical tank.


2012 ◽  
Vol 446-449 ◽  
pp. 2290-2294
Author(s):  
Wen Liang Qiu ◽  
Meng Jiang ◽  
Xing Bo Zhang

For floating system cable-stayed bridge, the longitudinal displacement of stiffening girder and moments of towers are very large when strong earthquake happens. Too large displacement of stiffening girder leads to collision between girders of the main bridge and the approaches. Using spatial finite element model and time history analysis method, the seismic responses of cable-stayed bridge are studied considering the elasto-plastic effects. The results show that the displacement of stiffening girder is very large when no seismic reduction measures are adopted. The viscous dampers installed between the stiffening girder and towers can efficiently reduce seismic responses of the cable-stayed bridge. Especially, the displacement of stiffening girder can be controlled well to meet the design requirement. Using the optimum parameters of damper, the height of pier under tower and intermediate supports in side span on seismic responses are studied in detail. The longitudinal displacement of stiffening girder increases with the pier height increasing. The intermediate supports in side span are benefit for seismic reduction.


2010 ◽  
Vol 102-104 ◽  
pp. 150-154
Author(s):  
Xiao Ping Hu ◽  
Xiao Ping Ye

The seismic load usually has a significant hazard to the safety of the tower equipment, so it’s important to execute of seismic design in engineering practice. In this paper, the time history analysis of the seismic response is carried out with the help of ANSYS software for the finite element model of the adsorption tower. Relevant time history data is obtained. Compared with seismic analysis of the current standard method, corresponding suggestions are given.


2012 ◽  
Vol 503-504 ◽  
pp. 1104-1107
Author(s):  
Shi Qing Lu ◽  
Han Bin Xiao ◽  
Ping Deng

Earthquakes pose a threat to large-scale container cranes. Previous earthquakes damaged many container cranes, which had a significant impact on business interruption losses of the port. In this paper, a container crane’s seismic response is analyzed in ANSYS. First, a finite element model of a container crane is developed. Then, based on the equations of structural dynamics, the four most important modes of the container crane are extracted. Finally, a time history analysis is conducted to obtain the displacements of some critical nodes on the crane model under the excitation of an earthquake wave. The result of this paper provides a reference for the seismic design of container cranes.


Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano

AbstractThe Italian code requires spectrum compatibility with mean spectrum for a suite of accelerograms selected for time-history analysis. Although these requirements define minimum acceptability criteria, it is likely that code-based non-linear dynamic analysis is going to be done based on limited number of records. Performance-based safety-checking provides formal basis for addressing the record-to-record variability and the epistemic uncertainties due to limited number of records and in the estimation of the seismic hazard curve. “Cloud Analysis” is a non-linear time-history analysis procedure that employs the structural response to un-scaled ground motion records and can be directly implemented in performance-based safety-checking. This paper interprets the code-based provisions in a performance-based key and applies further restrictions to spectrum-compatible record selection aiming to implement Cloud Analysis. It is shown that, by multiplying a closed-form coefficient, code-based safety ratio could be transformed into simplified performance-based safety ratio. It is shown that, as a proof of concept, if the partial safety factors in the code are set to unity, this coefficient is going to be on average slightly larger than unity. The paper provides the basis for propagating the epistemic uncertainties due to limited sample size and in the seismic hazard curve to the performance-based safety ratio both in a rigorous and simplified manner. If epistemic uncertainties are considered, the average code-based safety checking could end up being unconservative with respect to performance-based procedures when the number of records is small. However, it is shown that performance-based safety checking is possible with no extra structural analyses.


2012 ◽  
Vol 166-169 ◽  
pp. 2138-2142
Author(s):  
Hui Min Wang ◽  
Liang Cao ◽  
Ji Yao ◽  
Zhi Liang Wang

For the complex features in the form of a flat L-shaped reinforced concrete frame structure, the three dimensional FEM model of the structure was established in this paper, and the dynamic characteristics of the structure was analyzed, the participation equivalent mass of every mode’s order was obtained. Seismic response analysis for the structure was carried out with modal decomposition spectrum method and time history analysis method, the weak layer of the structure was pointed out and the reference for the structural design was provided.


Author(s):  
Soon Myeon Wang ◽  
J. S. Kim ◽  
T. E. Jin ◽  
M. J. Jhung ◽  
Y. H. Choi ◽  
...  

The structural integrity of integral reactor assembly of 65Mwt thermal capacity is assessed by using the commercial finite element package ANSYS in order to evaluate the seismic safety margin. First of all, the modal analyses are performed using the various analysis models with/without the fluid coupling effect in order to validate a super element model and to evaluate the coupling effect on natural frequency. Based on the modal analysis results, the seismic analyses are performed using the ground response spectrum defined in Reg. Guide 1.60. Finally, time-history analyses are performed using the modal analysis results, the super element model and an inertia load approach. As a result, the reliable and efficient seismic analysis model for an integral reactor assembly is developed and it is found that an integral reactor assembly has the sufficient seismic safety margin.


2013 ◽  
Vol 353-356 ◽  
pp. 2015-2019
Author(s):  
Zhi Hua Xiong ◽  
Yun Cheng Feng ◽  
Song Lin Song ◽  
Jiang Bo Wang

To ensure seismic safety of a large span cable-stayed bridge, two alternative pylon shapes and section types were studied. Nonlinear time history analysis was performed in the context. It is found that the A-shaped pylon is much stiffener than the H-shaped pylon in terms of deformation. The steel A-shaped pylon can significantly reduce the seismic demands of the key member including tower drift and moment. A ductile steel link between towers is proposed for the optimization of design in the paper. The A-shaped reinforced concrete tower with ductile steel link was proved to be a relatively balanced plan considering engineering, aesthetic and economic factors.


2012 ◽  
Vol 535-537 ◽  
pp. 2007-2011
Author(s):  
Da Feng Gao ◽  
Lei Wang ◽  
Peng Fei Li

In order to further study the seismic mechanism of ancient timber structure, the wooden structure of the temple was taken as the research object, and the reasonable mechanical model was established by applying semi-rigid spring element to simulate mortise-tenon joint, tou-kung and column base. The test of the compressive, bent and the shear capacity all met requirements by analyzing the model under the static load, and the average safety margin of the structure is 86.7%. The first six inherent frequencies and vibration shapes were obtained by analysing the finite element model using the method of Block Lanczos, With full transient analysis, considered the model in the El-Centro wave, Taft wave and Lanzhou artificial wave excitation under the three earthquake time history analysis, and got the model acceleration time history curves, the results show that the ancient Chinese timber structure has better aseismic performance. The above-mentioned methods and corresponding conclusions could provide the reference for maintenance and protection of ancient Chinese timber structure.


2013 ◽  
Vol 353-356 ◽  
pp. 2210-2215
Author(s):  
Jun Jun Wang ◽  
Lu Lu Yi

Modal analysis is also known as dynamic analysis for mode-superposition method. In the seismic response analysis of linear structural systems, it is one of the most commonly used and the most effective ways. Through the modal analysis of building structure, we can get some basic performance parameters of the structure. These parameters can help us make qualitative judgments for the respond of a structure first, and can help us judge whether they meet demands for conceptual design. Modal analysis is also the basis of other dynamic response analysis, including dynamic time history analysis and response spectrum analysis.


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