scholarly journals A study on a load combination method for multi-supported piping systems. Fundamental investigation using piping system with two inputs.

1987 ◽  
Vol 30 (263) ◽  
pp. 792-798
Author(s):  
Akira SONE ◽  
Kohei SUZUKI
Keyword(s):  
Combination Method ◽  
Piping System ◽  
Load Combination ◽  
Fundamental Investigation ◽  
Piping Systems

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.”

A Load Combination Method for Seismic Design of Multiple Supported Piping Systems With Friction Characteristics: Part 1—Generally Correlated Excitations

2011 ◽  
Author(s):  
Tatsuya Yamauchi ◽  
Kazumasa Tsuchikawa ◽  
Arata Masuda ◽  
Akira Sone
Keyword(s):  
Cross Correlation ◽  
Reduction Factor ◽  
Combination Method ◽  
Piping System ◽  
Theory Approach ◽  
Friction Characteristics ◽  
Response Reduction Factor ◽  
Load Combination ◽  
Piping Systems ◽  
The Cross

A load combination method for seismic response calculation of piping systems with friction characteristics to multiple support excitations is presented. This method has an advantage, such that the cross-correlation among support excitations and “response reduction factor” due to friction are taken into account by use of a stationary random vibration theory approach. Using a simple analytical SDOF piping system with friction characteristics to two support excitations, This method is supplied to various correlation cases of two support excitations and friction characteristics and the maximum responses of piping is calculated. From these calculation results, it is clear that the maximum acceleration responses of nonlinear piping systems can also depend on the cross-correlation among support excitations and can be reduced due to the friction effect. Finally, the conventional equation of the response reduction factor and the maximum response calculated by the proposed method are presented for practical use.

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.

A Load Combination Method for Seismic Design of Multiple Supported Piping Systems With Friction Characteristics: Part 2—Correlated Excitations Considering Characteristics of Supports

2011 ◽  
Author(s):  
Tatsuya Yamauchi ◽  
Kazumasa Tsuchikawa ◽  
Atsushi Yokota ◽  
Arata Masuda ◽  
Akira Sone
Keyword(s):  
Reduction Factor ◽  
Combination Method ◽  
Response Analysis ◽  
Piping System ◽  
Theory Approach ◽  
Maximum Acceleration ◽  
Friction Characteristics ◽  
Response Reduction Factor ◽  
Piping Systems ◽  
Calculation Results

Seismic response analysis of piping systems with friction characteristics to multiple support excitations is presented. By this analysis, the maximum responses of piping system are calculated and “response reduction factor” due to friction are taken into account by use of a stationary random vibration theory approach. Using a simple analytical SDOF piping system with friction characteristics to two support excitations, This method is supplied to various support cases with two support excitations and friction characteristics and the maximum responses of piping is calculated. From these calculation results, it is clear that the maximum acceleration responses of nonlinear piping systems can be reduced due to the friction effect. Finally, the conventional equation of the response reduction factor and the maximum response calculated by the proposed method are presented for practical use.

Non-Linear Design Verification of Nuclear Power Piping According to ASME III NB/NC

2008 ◽  
Author(s):  
Lingfu Zeng ◽  
Lennart G. Jansson
Keyword(s):  
Nuclear Power ◽  
Design Evaluation ◽  
Piping System ◽  
Design Verification ◽  
Intensive Study ◽  
Non Linear ◽  
Piping Systems ◽  
Design Requirements

A nuclear piping system which is found to be disqualified, i.e. overstressed, in design evaluation in accordance with ASME III, can still be qualified if further non-linear design requirements can be satisfied in refined non-linear analyses in which material plasticity and other non-linear conditions are taken into account. This paper attempts first to categorize the design verification according to ASME III into the linear design and non-linear design verifications. Thereafter, the corresponding design requirements, in particular, those non-linear design requirements, are reviewed and examined in detail. The emphasis is placed on our view on several formulations and design requirements in ASME III when applied to nuclear power piping systems that are currently under intensive study in Sweden.

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane, and Mixed Mode Bending Under Seismic Load: An Experimental Approach

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori
Keyword(s):  
Dynamic Behavior ◽  
Failure Modes ◽  
Seismic Load ◽  
Piping System ◽  
Shake Table ◽  
Shake Table Tests ◽  
Wall Thinning ◽  
Piping Systems ◽  
Out Of Plane ◽  
Plane Bending

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.

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