Study on Seismic Response Characteristics of Piping Systems with Elastic-Plastic Pipe Supports

2019 ◽  
Vol 2019 (0) ◽  
pp. J10304
Author(s):  
Akira MAEKAWA ◽  
Michiaki SUZUKI
Keyword(s):  
Seismic Response ◽  
Elastic Plastic ◽  
Response Characteristics ◽  
Plastic Pipe ◽  
Piping Systems

Impact of Inelastic Seismic Design Using Elastic-plastic Pipe Supports On Vibration Response of Piping Systems

2021 ◽  
Author(s):  
Akira Maekawa ◽  
Tsuneo Takahashi
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Power Plants ◽  
Response Analysis ◽  
Plastic Behavior ◽  
Piping System ◽  
Application Range ◽  
Elastic Plastic ◽  
Plastic Pipe ◽  
Piping Systems

Abstract This study presents the response mitigation effect of piping systems by inelastic seismic design based on elastic-plastic property of steel pipe supports. The inelastic seismic design to control vibration by absorbing energy using elastic-plastic properties of materials can be one of useful ideas. The design idea to use the elastic-plastic behavior of pipe supports is addressed in Technical Code for Seismic Design of Nuclear Power Plants (JEAC4601) published by the Japan Electric Association in Japan. Here, the component named an elastic-plastic pipe support is proposed as an energy-absorbing element. However, in order to put the inelastic seismic design using the elastic-plastic pipe supports into practical use, it is necessary to accumulate more findings related to the seismic response and the application range. This study aims to investigate the applicability of the inelastic seismic design taking the elastic-plastic pipe supports in the piping systems and to increase the basic findings. In this study, the seismic response analysis using three-dimensional piping system with an elastic-plastic pipe support was conducted. As a result, it was found that the elastic-plastic pipe support affected the seismic response largely. Additionally, the vibration characteristics, the response acceleration, and the load generated in the piping system were discussed relating to the plastic deformation and the plasticity rate of the elastic-plastic pipe support.

scholarly journals Seismic Response Characteristics of Stabilizing Pile Based on Elastic-Plastic Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Honglue Qu ◽  
Ying Liu ◽  
Hao Luo ◽  
Huanguo Hu ◽  
Qindi Hu
Keyword(s):  
Plastic Zone ◽  
Seismic Response ◽  
Ground Motion ◽  
Seismic Design ◽  
Design Parameters ◽  
Plastic State ◽  
Elastic Plastic ◽  
Stabilizing Pile ◽  
Response Characteristics ◽  
Plastic Analysis

Stabilizing pile is widely used in the landslide controlling projects and shows excellent seismic performance under the action of earthquake. Therefore, in order to improve seismic design theory, it is of importance to study the seismic response characteristics of stabilizing pile based on elastic-plastic analysis. In view of this, elastic-plastic constitutive model was established to deduce the plastic zone of stabilizing pile. Based on elastic-plastic analysis, the seismic response characteristics and the influence of different section sizes, material strengths, and peak ground motion acceleration (PGA) were analyzed by ANSYS 3D. Resultantly, the elastic-plastic fourth-order tensor Cijklep was deduced, which can be used to calculate plastic strain of stabilizing pile under loading. Compared with Chinese code, the material of stabilizing pile working with elastic-plastic state will be decreased under the same section size and the same property. Furthermore, stabilizing pile is in the elastic stage at the beginning under the action of earthquake. With the increase of ground motion time, the section starts to exhibit elastic-plastic state and then the plastic zone expands gradually. Finally, the plastic zone runs through the whole section, resulting in the performance loss of the pile. In addition, under the different design parameters, pile shows different seismic response characteristics; namely, changing these parameters reasonably can improve the seismic design.

Numerical Study on Inelastic Seismic Design of Piping Systems Using Damping Effect Based on Elastic–Plastic Property of Pipe Supports

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Akira Maekawa ◽  
Tsuneo Takahashi
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Plastic Property ◽  
Damping Coefficient ◽  
Seismic Load ◽  
Piping System ◽  
Elastic Plastic ◽  
Damping Effect ◽  
Modal Damping ◽  
Piping Systems

This study describes inelastic seismic design of piping systems considering the damping effect caused by elastic–plastic property of a pipe support which is called an elastic–plastic support. Though the elastic–plastic support is proposed as inelastic seismic design framework in the Japan Electric Association code for the seismic design of nuclear power plants (JEAC4601), the seismic responses of the various piping systems with the support are unclear. In this study, the damping coefficient of a piping system is focused on, and the relation between seismic response of the piping system and elastic–plastic behavior of the elastic–plastic support was investigated using nonlinear time history analysis and complex eigenvalue analysis. The analysis results showed that the maximum seismic response acceleration of the piping system decreased largely in the area surrounded by pipe elbows including the elastic–plastic support which allowed plastic deformation. The modal damping coefficient increased a maximum of about sevenfold. Furthermore, the amount of the initial stiffness of the elastic–plastic support made a difference in the increasing tendency of the modal damping coefficient. From the viewpoint of the support model in the inelastic seismic design, the reduction behavior for the seismic response of the piping system was little affected by the 10% variation of the secondary stiffness. These results demonstrated the elastic–plastic support is a useful inelastic seismic design of piping systems on the conditions where the design seismic load is exceeded extremely.

Elastic-Plastic Seismic Response Analysis on the Special-Shaped Chimney

2014 ◽  
Vol 711 ◽  
pp. 520-524 ◽  
Author(s):  
Huan Qin Liu ◽  
Wei Bin Li ◽  
Ruo Yang Wu ◽  
Lin Fei Yan
Keyword(s):  
Seismic Response ◽  
Dynamic Performance ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Elastic Plastic ◽  
Loading Mode ◽  
Loading Patterns ◽  
Displacement Angle

Based on one 240-meter-high special-shaped RC chimney, the structure’s dynamic performance and elastic-plastic seismic response analysis has been studied in detail. From the analysis, it demonstrates the weak areas in the chimney. The interlayer displacement angle about corresponding performance points under four kinds of loading mode were also acuired, and the response of four loading patterns were analyzed.

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