A Comparative Study of Combination Methods Used in Response Spectrum Analysis of Nuclear Piping Systems

1984 ◽  
Vol 106 (1) ◽  
pp. 25-31 ◽  
Author(s):  
S. Gupta ◽  
D. P. Jhaveri ◽  
O. Kustu ◽  
J. A. Blume
Keyword(s):  
Spectrum Analysis ◽  
Response Spectrum ◽  
Nuclear Regulatory Commission ◽  
Dynamic Responses ◽  
Combination Method ◽  
Response Spectrum Analysis ◽  
Combination Methods ◽  
Piping Systems ◽  
Regulatory Commission ◽  
The U.S

The different methods of combining responses for individual modes and directions for response spectrum analysis of nuclear piping systems are evaluated. For the purpose of the study, dynamic responses of 20 typical piping systems using nine different combination methods are systematically compared. The study established the relative conservatism in design achieved by each method and the probability that a particular combination method will produce a more conservative estimate of seismic response than obtained using one of the methods accepted by the U.S. Nuclear Regulatory Commission.

Modal Combination in Response Spectrum Analysis of Piping Systems

1986 ◽  
Vol 108 (1) ◽  
pp. 73-77 ◽  
Author(s):  
A. K. Gupta ◽  
J.-W. Jaw
Keyword(s):  
Spectrum Analysis ◽  
Response Spectrum ◽  
Direct Integration ◽  
Response Spectrum Analysis ◽  
Combination Rules ◽  
Combination Methods ◽  
Modal Response ◽  
Piping Systems ◽  
Higher Modes Effect ◽  
Integration Analysis

Modal combination methods in the response spectrum analysis of piping systems have been investiaged. Two particular effects are identified, viz, (i) the residual rigid response, also known as the higher modes effect (HME); (ii) the correlation between the modal response and the rigid response. Gupta’s method accounts for both these effects. It is shown that Gupta’s method gives results which are much closer to the direct integration analysis results than are the results obtained from any other modal combination rules which ignore either one or both of the foregoing effects.

The Application of Combination of Individual Modal Responses According to the Revised RG1.92

2010 ◽  
Author(s):  
Shenghua Liu ◽  
Zufeng Xia
Keyword(s):  
Nuclear Power ◽  
Parametric Design ◽  
Nuclear Regulatory Commission ◽  
Nuclear Industry ◽  
Combination Method ◽  
Response Analysis ◽  
Comparison Result ◽  
Combination Methods ◽  
Regulatory Commission ◽  
Double Sum

The U.S. Nuclear Regulatory Commission (NRC) issued the revised regulatory guide 1.92 as Rev. 2 on July 2006, which is believed to efficiently reduce the unnecessary conservative which is introduced by combination methods specified in RG1.92 Rev.1 and to be acceptable for combining modal responses and spatial components in seismic response analysis of nuclear power plant structures, systems, and components (SSCs). But it is still impossible to use this method to do the combination of spectrum response analysis, because most popular general finite element programs do not develop a reasonable command or macros according to RG1.92 Rev.2. In order to perform the combination of individual modal responses according to this new guide conveniently, this paper developed a macro file used the ANSYS Parametric Design Language (APDL) based on ANSYS program which is widely used in nuclear industry. This paper examined the macro file with an actual support pipe, and compared the results got from the new method with the results acquired from previously accepted method such as double sum method and grouped method. The comparison result shows that the revised combination method actually reduced the unnecessary conservative previously accepted by method in RG1.92, Rev.1, also the results prove that the macro file this paper established is reasonable.

Generalized Response Spectrum Analysis for Structures with Dampers

2018 ◽  
Vol 34 (3) ◽  
pp. 1459-1479 ◽  
Author(s):  
Yuki Terazawa ◽  
Toru Takeuchi
Keyword(s):  
Spectrum Analysis ◽  
Nonlinear Response ◽  
Response Spectrum ◽  
Combination Method ◽  
Axial Stiffness ◽  
Response Spectrum Analysis ◽  
History Analysis ◽  
Response History Analysis ◽  
Nonlinear Response History Analysis ◽  
Damped Systems

In this study, a computational seismic design routine is proposed based on a generalized response spectrum analysis for highly indeterminate structures with energy-dissipation members, such as viscous or elasto-plastic dampers. Complex stiffness terms are introduced to account for displacement-dependent damping, and a three-dimensional (3-D) element stiffness matrix with complex axial stiffness is proposed for elasto-plastic dampers. A modified complete quadratic combination method previously developed for real symmetric damped systems is extended to complex asymmetric damped systems, based on a theoretical analysis of eigenvalue equations. The response is evaluated by iteratively conducting complex eigenvalue analysis and modal combination. The accuracy is confirmed through comparison to nonlinear response history analysis of 2-D frame models. Finally, an example application is presented of a 3-D truss tower seismically retrofitted by replacing the braces with viscoelastic and then elasto-plastic dampers. The proposed design routine is used to rapidly identify novel and efficient damper arrangements and sizing distributions, avoiding computationally intensive nonlinear response history analysis.

Seismic Evaluation Method of Piping Systems by Inelastic Response Spectrum Analysis: Part 1 — Response Analysis

2019 ◽  
Author(s):  
Ichiro Tamura ◽  
Michiya Sakai ◽  
Shinichi Matsuura ◽  
Ryuya Shimazu ◽  
Hiroaki Tamashiro ◽  
...  
Keyword(s):  
Spectrum Analysis ◽  
Evaluation Method ◽  
Response Spectrum ◽  
Vibration Test ◽  
Piping System ◽  
Analysis Method ◽  
Seismic Evaluation ◽  
Response Spectrum Analysis ◽  
Inelastic Response ◽  
Piping Systems

Abstract An inelastic response-spectrum-analysis method for multi-degree-of-freedom systems was proposed. The method has lower analysis loads and good outlook given by the inelastic response spectrum like the elastic response-spectrum-analysis method, and is not an equivalent-linearization method. We propose a seismic evaluation method of piping systems to conduct seismic design using the inelastic response-spectrum-analysis. In this paper, the inelastic analysis method of piping systems for the seismic evaluation method is proposed and applied to a benchmark analysis problem of a piping system vibration test. The analysis result is compared with the vibration test result of the piping system. They are consistent and applicability of the analysis to the piping system was confirmed.

scholarly journals Alternate modal combination methods in response spectrum analysis

1990 ◽  
Author(s):  
P. Bezler ◽  
J.R. Curreri ◽  
Y.K. Wang ◽  
A.K. Gupta
Keyword(s):  
Spectrum Analysis ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Combination Methods

Comparison of eigenanalysis and Ritz vector approaches for response spectrum analysis of soil-pile-bridge systems

2021 ◽  
Vol 17 (3-4) ◽  
pp. 89-100
Author(s):  
M. Davidson ◽  
A. Patil ◽  
S.A. Rosenfeld ◽  
Z. Zhu
Keyword(s):  
Spectrum Analysis ◽  
Soil Structure ◽  
Response Spectrum ◽  
Active Regions ◽  
Ritz Vector ◽  
Response Spectrum Analysis ◽  
Fixed Base ◽  
Potential Benefits ◽  
Eigenvectors And Eigenvalues ◽  
Vector Approach

Frequency-based analysis techniques such as response spectrum analysis (RSA) are widely used for designing bridges in seismically active regions. Two well-known analysis procedures that underlie RSA are the solution of the eigenproblem and the approximation of the solution to the eigenproblem (i.e., approximation of eigenvectors and eigenvalues) through use of force-dependent Ritz vectors. While frequency-based methods have achieved widespread adoption in practice, certain simplifications remain common, such as neglecting soil-structure interaction (SSI) due to a fixed-base assumption. In the present study, frequency-based techniques packaged within a research version of a design-oriented computational tool are employed to analyze, assess, and compare results obtained from RSA with use of the eigenanalysis, and separately, Ritz vector approaches. Importantly, for the bridge configurations analyzed, SSI is taken into account. As outcomes, the potential benefits of the Ritz vector approach (as well as modeling strategies) are demonstrated. The study outcomes are intended to aid practicing engineers when the need to account for SSI is recognized as pertinent to a given bridge seismic design application.

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