Seismic response of the secondary piping system under bi-directional earthquake

2021 ◽  
Author(s):  
Vishal Kamble ◽  
Shiv Dayal Bharti ◽  
Mahendra Kumar Shrimali
Keyword(s):  
Seismic Response ◽  
Piping System

The Influence of Support Hardware and Piping System Seismic Response on Snubber Support Damping

1997 ◽  
Vol 119 (4) ◽  
pp. 451-456 ◽  
Author(s):  
C. Lay ◽  
O. A. Abu-Yasein ◽  
M. A. Pickett ◽  
J. Madia ◽  
S. K. Sinha
Keyword(s):  
Seismic Response ◽  
Fundamental Frequency ◽  
Damping Ratio ◽  
Damping Coefficient ◽  
Piping System ◽  
Nodal Displacement ◽  
Damping Coefficients ◽  
Fundamental Frequencies ◽  
Piping Systems

The damping coefficients and ratios of piping system snubber supports were found to vary logarithmically with pipe support nodal displacement. For piping systems with fundamental frequencies in the range of 0.6 to 6.6 Hz, the support damping ratio for snubber supports was found to increase with increasing fundamental frequency. For 3-kip snubbers, damping coefficient and damping ratio decreased logarithmically with nodal displacement, indicating that the 3-kip snubbers studied behaved essentially as coulomb dampers; while for the 10-kip snubbers studied, damping coefficient and damping ratio increased logarithmically with nodal displacement.

A simplified method for inelastic piping system seismic response prediction

1988 ◽  
Vol 107 (1-2) ◽  
pp. 169-181 ◽  
Author(s):  
K.R. Jaquay ◽  
J.E. Larson ◽  
H.T. Tang
Keyword(s):  
Seismic Response ◽  
Response Prediction ◽  
Piping System ◽  
Simplified Method

Seismic response analysis of a piping system subjected to multiple support excitations in a base isolated NPP building

2015 ◽  
Vol 292 ◽  
pp. 283-295 ◽  
Author(s):  
Han-Bum Surh ◽  
Tae-Young Ryu ◽  
Jin-Sung Park ◽  
Eun-Woo Ahn ◽  
Chul-Sun Choi ◽  
...  
Keyword(s):  
Seismic Response ◽  
Response Analysis ◽  
Piping System ◽  
Seismic Response Analysis ◽  
Multiple Support

Simplified Seismic Response Analysis Method Using Reduced Model of Piping System

2018 ◽  
Author(s):  
Michiya Sakai ◽  
Ryuya Shimazu ◽  
Shinichi Matsuura ◽  
Ichiro Tamura
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Seismic Response ◽  
Degrees Of Freedom ◽  
Response Analysis ◽  
Piping System ◽  
Element Analysis ◽  
Mass System ◽  
Piping Systems ◽  
Low Degrees

In the seismic response analysis of piping systems, finite element analysis is performed with analysis method guidelines [1]–[4] established based on benchmark analysis. However, since it takes a great deal of effort to carry out finite element analysis, a simplified method to analyze the seismic response of complex piping systems is required. In this research, we propose a method to reduce an equivalent spring-mass system model with low degrees of freedom, which can take into account the main mode of the complicated piping system. Simplified seismic evaluation is carried out using this spring mass system model with low degrees of freedom, and the accuracy of response evaluation is confirmed by comparison with finite element analysis.

Determination of Support Minimum Rigid Stiffness for Piping Analysis

2015 ◽  
Author(s):  
Jennifer Huang ◽  
Timothy M. Adams
Keyword(s):  
Lower Bound ◽  
Seismic Response ◽  
Natural Frequency ◽  
Iterative Process ◽  
Piping System ◽  
Alternative Approach ◽  
Formal Procedure ◽  
Deflection Criteria ◽  
Spring Constants

Pipe supports are represented as spring constants in piping analysis, and therefore a formal procedure is required to determine the spring constant values. Two current approaches are to enforce deflection criteria to ensure support rigidity or calculate the support stiffness values directly. However, the former approach results in overly conservative support designs and the latter approach becomes an iterative process of designing the supports and observing the response of the piping system. To avoid the issues presented by these methods, an alternative approach is presented which involves increasing values of support stiffness until change in natural frequency of the system diminishes. This method can help establish a lower bound (minimum rigid) stiffness above which there will be no significant change in the seismic response of the piping system. Using this approach only requires the support designs to have stiffness values at or above the minimum value without being concerned with detailed stiffness calculations or using deflection limits. This paper presents the methods and results of an expansive study to establish minimum rigid stiffness values for piping analysis.

scholarly journals Proving Test on Seismic Reliability of Piping System with Energy Absorbing Supports. (Verification of Seismic Response Analysis Method of Piping System).

1998 ◽  
Vol 41 (2) ◽  
pp. 192-198 ◽  
Author(s):  
Kohei SUZUKI ◽  
Youichi SASAKI ◽  
Hiroshi ABE ◽  
Katsuhiko KURODA ◽  
Yoshio NAMITA ◽  
...  
Keyword(s):  
Seismic Response ◽  
Response Analysis ◽  
Piping System ◽  
Analysis Method ◽  
Seismic Response Analysis ◽  
Seismic Reliability ◽  
Energy Absorbing

Seismic Fragility Evaluation of Interface Pipes in Seismically Isolated NPPs by Using Scale Model Test

2015 ◽  
Author(s):  
Daegi Hahm ◽  
Min-Kyu Kim ◽  
In-Kil Choi ◽  
Bub Gyu Jeon ◽  
Hyoung Suk Choi ◽  
...  
Keyword(s):  
Seismic Response ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Response Analysis ◽  
Seismic Events ◽  
Piping System ◽  
Seismic Response Analysis ◽  
Secondary Systems ◽  
Inelastic Seismic Response ◽  
Isolation Device

Seismic isolation system can be an effective alternative to protect the NPPs (Nuclear Power Plants) against to the strong seismic events. Therefore, some research activities to adopt the seismic isolation concept to the design of the next generation NPPs have been progressed for last few years in Korea. Nuclear structures, secondary systems and components must remain undamaged during and after the SSE (Safe Shutdown Earthquake) event. The seismic events will cause the high seismic response in the stiff structural systems and extremely high demands of deformation on the safety-related secondary systems like piping components. If seismic isolation devices are installed in nuclear power plant for seismic stability, safety against seismic load of power plant may be improved. But in some equipment, seismic risk may increase because displacement may become greater than before installation of seismic isolation device. Therefore, it is necessary to select the equipment in which seismic risk increases due to increase in displacement by the installation of seismic isolation device, and perform a research on seismic performance evaluation of equipment. In this study, one of the typical Korean NPPs assuming the application of seismic isolation devices, and one of the interface piping systems which introduced this NPP was used for seismic analysis. The numerical models include representations of seismic isolation devices. In order to validation of numerical piping system model and defining failure mode & limit states, quasi-static loading tests were conducted on the scale-modeled piping components before the analysis procedures. The fragility analysis was performed by using results of inelastic seismic response analysis. Inelastic seismic response analysis was carried out by using shell finite element model of piping system considering internal pressure. The implicit method was used for the direct integration time history analysis. Generally, PGA (Peak Ground Acceleration) was used for seismic intensity of fragility curve. However, in the case of the displacement sensitive system, lateral displacement could be an useful alternative measure for estimation of probability of failure. Thus in this paper, fragility curves were plotted based on maximum relative displacement.

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