A Test and Analysis of the Multiple Support Piping Systems

1989 ◽  
Vol 111 (3) ◽  
pp. 291-299 ◽  
Author(s):  
T. Chiba ◽  
R. Koyanagi ◽  
N. Ogawa ◽  
C. Minowa
Keyword(s):  
Large Scale ◽  
Response Spectrum ◽  
Steel Structures ◽  
Response Spectra ◽  
Piping System ◽  
Multiple Response ◽  
Actual Behavior ◽  
Test Results ◽  
Piping Systems ◽  
Multiple Support

One of the current topics in the seismic design of piping systems is the overall reliability of them in earthquake events. Actual piping systems are generally supported by independent structures such as vessels and steel structures. So, it is very important to clarify the behavior of actual piping systems during the seismic events. For this purpose, the analytical method of multiple excitation problems is a preferable approach to not only evaluate the actual behavior of the piping systems, but also improve the reliability of piping systems. To clarify the dynamic characteristics of the piping systems and to assess the computational methods in the linear system subjected to multiple support excitations, an experimental study using a realistic large-scale piping model has been conducted. The equations for the multiple excitation problem have been validated and the adequacy of the multiple response spectra method has been confirmed by the comparison of the test results with the analytical one. This paper reports the results focusing on the analytical methods of the multiple support piping system. It is noted that the multiple response spectrum method is efficient for the multiple excitation problems.

Seismic Proving Test of Ultimate Piping Strength: Test Results on Piping Component and Simplified Piping System

2002 ◽  
Author(s):  
Kenichi Suzuki ◽  
Y. Namita ◽  
H. Abe ◽  
I. Ichihashi ◽  
Kohei Suzuki ◽  
...  
Keyword(s):  
Large Scale ◽  
Safety Margin ◽  
Current Status ◽  
Piping System ◽  
Test Results ◽  
Seismic Safety ◽  
System A ◽  
Seismic Design Code ◽  
Piping Systems ◽  
Technical Issues

In 1998FY, the 6 year program of piping tests was initiated with the following objectives: i) to clarify the elasto-plastic response and ultimate strength of nuclear piping, ii) to ascertain the seismic safety margin of the current seismic design code for piping, and iii) to assess new allowable stress rules. In order to resolve extensive technical issues before proceeding on to the seismic proving test of a large-scale piping system, a series of preliminary tests of materials, piping components and simplified piping systems is intended. In this paper, the current status of the piping component tests and the simplified piping system tests is reported with focus on fatigue damage evaluation under large seismic loading.

Shaking Table Tests of a Piping System With Viscoelastic Dampers Subjected to Severe Earthquake Motions

2016 ◽  
Author(s):  
Victor Kostarev ◽  
Ichiro Tamura ◽  
Masashi Kuramasu ◽  
Frank Barutzki ◽  
Petr Vasilev ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Piping System ◽  
Actual Behavior ◽  
Test Results ◽  
Viscoelastic Dampers ◽  
Piping Systems ◽  
Large Earthquakes ◽  
Very High

In Shimane Nuclear Power Plant of the Chugoku Electric Power Co. located in the West Japan area, a number of safety improvements are planned to be implemented aiming at achieving the highest world level in nuclear safety. One of the new safety approaches for seismic protection of NPPs is the application of viscoelastic dampers for safety related piping, systems and components. This technology is widely spread in nuclear power since 80s of the last century, [1 and 2]. In order to investigate and check the actual behavior of viscoelastic dampers installed at piping systems and subjected to severe earthquake motions, a shaking table test with full-scale piping and viscoelastic dampers was carried out. The shaking table test was performed for two general conditions. One is without aseismic devices and the other one is with viscoelastic dampers. It was confirmed by comparing the test results of the above mentioned two conditions that viscoelastic dampers provide to piping systems very high overall damping and protect piping systems even against large earthquakes.

A Load Combination Method for Aseismic Design of Multiple Supported Piping Systems

1989 ◽  
Vol 111 (1) ◽  
pp. 10-16 ◽  
Author(s):  
K. Suzuki ◽  
A. Sone
Keyword(s):  
Structural Model ◽  
Response Spectrum ◽  
Reduction Factor ◽  
Combination Method ◽  
Piping System ◽  
Response Reduction Factor ◽  
Load Combination ◽  
Combination Scheme ◽  
Piping Systems ◽  
Reduction Effect

A new load combination scheme for seismic response calculation of piping systems subjected to multiple support excitations is presented. This scheme has an advantage, such that the cross-correlation among support excitations are properly taken into account by use of a stationary random vibration approach. The authors also present the idea of generating a “multi-excitation floor response spectrum.” First, using a simple analytical SDOF piping system to two support excitations and a simple Z-shaped piping model for shaking test, the combination law is supplied to various correlation cases of two support excitations and the maximum responses of piping in a fundamental mode is calculated. Second, nonlinear characteristics such as gap and friction appearing between piping itself and supports are specifically investigated. The response effect due to these nonlinearities is evaluated by the results through the shaking test with a piping-support structural model, and the amount of response reduction effect is represented by “a response reduction factor β.”

Experimental Study on Seismic Responses of Piping Systems With Friction—Part 2: Simplified Analysis Method on the Effect of Friction

1995 ◽  
Vol 117 (3) ◽  
pp. 250-255
Author(s):  
H. Kobayashi ◽  
R. Yokoi ◽  
T. Chiba ◽  
K. Suzuki ◽  
N. Shimizu ◽  
...  
Keyword(s):  
Large Scale ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Analysis Method ◽  
Equivalent Viscous Damping ◽  
Piping Systems ◽  
Simplified Analysis ◽  
Reduction Effect ◽  
Vibration Tests ◽  
Equivalent Viscous Damping Ratio

Friction between pipe and support structure is generally known to reduce seismic response of the piping systems. Vibration tests using large-scale piping model with friction support were carried out to evaluate the reduction effect. The piping response was mainly governed by the first modal deformation. The simplified analysis method based on linear response spectrum analysis was developed and confirmed to be applicable. In this method, the reduction effect by friction is treated as equivalent viscous damping ratio. This paper deals with the analysis method, and the comparison between the experimental results and analytical ones.

Passive Control of Seismic Response of Piping Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 364-369 ◽  
Author(s):  
Y. M. Parulekar ◽  
G. R. Reddy ◽  
K. K. Vaze ◽  
K. Muthumani
Keyword(s):  
Passive Control ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Equivalent Linearization ◽  
Piping System ◽  
Equivalent Damping ◽  
History Analysis ◽  
Piping Systems

Passive energy dissipating devices, such as elastoplastic dampers (EPDs) can be used for eliminating snubbers and reducing the response of piping systems subjected to seismic loads. Cantilever and three-dimensional piping systems were tested with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping systems supported on elastoplastic damper. An iterative response spectrum method is used for evaluating response of the piping system using this equivalent damping. The analytical maximum response displacement obtained at the elastoplastic damper support for the two piping systems is compared with experimental values and time history analysis values. It has been concluded that the iterative response spectrum technique using Caughey equivalent damping is simple and results in reasonably acceptable response of the piping systems supported on EPD.

scholarly journals Nonlinear Seismic Correlation Analysis of the JNES/NUPEC Large-Scale Piping System Tests

2008 ◽  
Author(s):  
Jinsuo Nie ◽  
Giuliano DeGrassi ◽  
Charles H. Hofmayer ◽  
Syed A. Ali
Keyword(s):  
Correlation Analysis ◽  
Test Data ◽  
Nuclear Power ◽  
Large Scale ◽  
Failure Modes ◽  
Plastic Behavior ◽  
Piping System ◽  
Highly Nonlinear ◽  
Piping Systems ◽  
The U.S

The Japan Nuclear Energy Safety Organization/Nuclear Power Engineering Corporation (JNES/NUPEC) large-scale piping test program has provided valuable new test data on high level seismic elasto-plastic behavior and failure modes for typical nuclear power plant piping systems. The component and piping system tests demonstrated the strain ratcheting behavior that is expected to occur when a pressurized pipe is subjected to cyclic seismic loading. Under a collaboration agreement between the U.S. and Japan on seismic issues, the U.S. Nuclear Regulatory Commission (NRC)/ Brookhaven National Laboratory (BNL) performed a correlation analysis of the large-scale piping system tests using detailed state-of-the-art nonlinear finite element models. Techniques are introduced to develop material models that can closely match the test data. The shaking table motions are examined. The analytical results are assessed in terms of the overall system responses and the strain ratcheting behavior at an elbow. The paper concludes with the insights about the accuracy of the analytical methods for use in performance assessments of highly nonlinear piping systems under large seismic motions.

A Load Combination Method for Seismic Design of Multi-Degree-of-Freedom Piping Systems With Friction Characteristics and Multiple Support Systems

2014 ◽  
Author(s):  
Akira Sone ◽  
Tatsuya Yamauchi ◽  
Arata Masuda
Keyword(s):  
Degree Of Freedom ◽  
Combination Method ◽  
Piping System ◽  
Theory Approach ◽  
Maximum Acceleration ◽  
Friction Characteristics ◽  
Load Combination ◽  
Combination Scheme ◽  
Piping Systems ◽  
Multiple Support

A load combination scheme for seismic response calculation of multi-degree-of-freedom (MDOF) piping systems with friction characteristics to multiple support excitations is presented. This scheme has an advantage, such that the “response reduction factor” due to friction is taken into account by use of a stationary random vibration theory approach. Using a simple and analytical 5DOF piping system with friction characteristics to two support excitations, combination law is supplied to various friction characteristics and the maximum responses of piping is calculated. From these calculation results, it is clear that the maximum acceleration responses of piping systems calculated by the proposed scheme are reasonable compared with those by the numerical simulations.

Influence of Local Wall Thinning and Support Stiffness in Piping Systems on Safety Assessments for Dynamic Loading

2014 ◽  
Author(s):  
Klaus Kerkhof ◽  
Fabian Dwenger ◽  
Gereon Hinz ◽  
Siegfried Schmauder
Keyword(s):  
Stress Analysis ◽  
Response Spectrum ◽  
System Response ◽  
Piping System ◽  
Load Bearing ◽  
Wall Thinning ◽  
Safety Margins ◽  
Piping Systems ◽  
Bearing Behavior ◽  
Local Wall Thinning

The load bearing behavior of piping systems depends considerably on support distances and stiffness as well as cross section characteristics. Stiffness of supports can often be defined only with difficulty by applying simplified procedures or guidelines based on assumptions. Load cases can be estimated quite well, but the safety assessment of a piping system can only be as reliable as the system model can realistically describe the present support stiffness or imperfections e.g. local wall thinning. As a consequence, the prediction of the system response may be poor. It is likely that calculated frequencies differ from natural frequencies determined experimentally. These frequency shifts lead to unrealistic predictions of stress analysis. Examples for overestimations and underestimations of stress analysis are given regarding the load case earthquake, depending on whether the frequency shift runs into or out of the plateau of the applied floor response spectrum. The influence of local wall thinning on modal characteristics is investigated. Conservative estimations of the influence on the load bearing behavior regarding severe local wall thinning are given. For fatigue checks the linear response of an experimental piping system is calculated and safety margins are demonstrated by comparing calculated with experimental results.

Results From Dynamic Tests and Analyses of a Medium Diameter LMFBR Piping System

1986 ◽  
Vol 108 (3) ◽  
pp. 330-333
Author(s):  
G. A. Schott ◽  
G. M. Hulbert ◽  
C. F. Heberling
Keyword(s):  
Seismic Design ◽  
Large Diameter ◽  
Piping System ◽  
Fast Breeder Reactor ◽  
Test Results ◽  
Dynamic Tests ◽  
Test Program ◽  
Piping Systems ◽  
Seismic Tests ◽  
Medium Diameter

This paper presents results and observations from dynamic tests and analyses performed on an 8-in. (0.20-m) diameter, thin-walled piping system. The piping system is a scaled representation of a Liquid Metal Fast Breeder Reactor (LMFBR) large diameter piping loop. Prototypic piping restraints were employed, including mechanical snubbers, rigid struts, pipe hangers and nonintegral pipe clamps. Snap-back, sine-sweep and seismic tests were performed for various restraint configurations and piping conditions. The test results are compared to analytical predictions for verification of the methods and models used in the seismic design of LMFBR piping systems. Test program conclusions and general recommendations for piping seismic analyses are presented along with a discussion of test and analysis results.

scholarly journals As-built modeling of piping system from terrestrial laser-scanned point clouds using normal-based region growing

2014 ◽  
Vol 1 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Kazuaki Kawashima ◽  
Satoshi Kanai ◽  
Hiroaki Date
Keyword(s):  
Large Scale ◽  
Region Growing ◽  
Point Clouds ◽  
Recognition Algorithm ◽  
Cylinder Surface ◽  
Piping System ◽  
Plant Recognition ◽  
Piping Systems ◽  
Plant Equipment ◽  
Oil Rig

Abstract Recently, renovations of plant equipment have been more frequent because of the shortened lifespans of the products, and as-built models from large-scale laser-scamied data is expected to streamline rebuilding processes. However, the laser-scanned data of an existing plant has an enormous amount ofpoints, captures inmcate objects, and includes a high noise level, so the manual reconstmction of a 3D model is very time-consuming and costly. Among plant equipment, piping systems account for the greatest proportion. Therefore, the purpose of this research was to propose an algorithm which could automatically recognize a piping system from the terrestrial laser- scanned data plant equipment. The straight pomon pipes, connecting parts, and connection relationship ofthe piping system can be recognized in this algorithm. Normal-based region growing and cylinder surface fitting can extract all possible locations ofpipes, including straight pipes, elbows, and junctions. Tracing the axes of a piping system enables the recognition of the positions of these elements and their connection relationship. Using only point clouds, the recognition algorithm can be performed in a fUlly automatic way. The algorithm was applied to large-scale scamied data of an oil rig and a chemical plant. Recognition rates of about 86%, 88%, and 71% were achieved straight pipes, elbows, andjunctions, respectively.

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