Investigation on Effect of Analysis Variables on Structural Integrity of the Nuclear Piping Under Beyond Design Basis Earthquake

Author(s):  
Jong-Sung Kim ◽  
Suk-Hyun Lee ◽  
Hyeong Do Kweon

In this study, effect of analysis variables on structural integrity of nuclear piping under beyond design basis earthquake was investigated via performing dynamic time history seismic analysis. A finite element model of the piping system such as shut-down cooling line was developed combining solid and beam elements. Dynamic time history analysis was performed via finite element elastic plastic stress analysis. Validity of the dynamic time history analysis procedure was verified via comparing with the previous study results. Finally, the effect of analysis variables such as finite element characteristics, transition length between elbow and straight line, fluid effect, etc. was investigated via performing parametric dynamic time history seismic analysis. As a result, it was found that use of the 1st incompatible element is recommended, the transition length is the same as curvature of the elbow, and fluid has to be considered.

2013 ◽  
Vol 353-356 ◽  
pp. 979-983
Author(s):  
Dong Zhang ◽  
Jing Bo Su ◽  
Hui De Zhao ◽  
Hai Yan Wang

Due to the upgrade and reconstruct of a high-piled wharf, the piling construction may cause the damage of the large diameter underground pipe of a power plant nearby. For this problem, a dynamic time-history analysis model was established using MIDAS/GTS program. Based on the analysis of the pile driving vibration and its propagation law, some parameters, such as the modulus of the soil, the Poissons ratio of soil, the action time of vibration load and the damping ratio of the soil that may have an effect on the response law of the soil, were studied. The study results not only serve as an important inference to the construction of this case, but also accumulate experience and data for other similar engineering practices.


2011 ◽  
Vol 243-249 ◽  
pp. 1401-1404
Author(s):  
Yan Xia Ye ◽  
Jing Zhao

In order to study the influence of dynamic response of frame-support-wall structure with openings on floor, six 3D models with different radio of opening are made. According to the finite element mode analysis and dynamic time-history analysis, we know that the location of openings, the size of openings etc. are important to the performance of structure. In order to keep entire structure in good condition, we suggest that the rate of openings should be smaller than 6%~8%.


2012 ◽  
Vol 446-449 ◽  
pp. 824-828
Author(s):  
Qing Sheng Guo ◽  
Qing Shan Yang

A structure with steel staggered-truss (SST) system is numerically investigated in this paper, utilizing the finite element 3D simulation analytial soft ware ETABS. Two different 3D models considering or ignoring the stiffness of infilled walls (SIW) are analyzed with Dynamic Time History method including storey drift and equivalent base shear force under frequent earth quake and rare earth quake. Results indicate that the effect of the SIW is prominent and should be considered.


Author(s):  
Jinho Oh ◽  
Jeong-Soo Ryu ◽  
Young-Ki Kim

The objective of this study is to design the spent fuel storage rack (SFSR) and their support frame as well as to evaluate the structural integrity of those during and after the seismic events. The main function of these racks is to store and protect the irradiated fuel assemblies generated during the operation of the research reactor. Their support frame is used for maintaining the structural stability of these racks. The SFSRs and their support frame are classified into safety class NNS and seismic category I according with ANSI 51.1 [1] and Regulatory Guide 1.29 [2]. The design of those has been performed according to the guideline of Regulatory Guide 1.13 [3] and IAEA safety standards DS 350 [4]. Specially, the pitch among storage cells should be decided from the criticality calculation with all postulated assumptions according to the NUREG 1537 [5] (Effective Neutron Multiplication Factor, keff < 0.9), conservatively. These racks are installed in their support frame having free standing type boundary conditions in the pool. Since the dynamic behavior of structures can be significantly affected by the water, the hydrodynamic effect is considered by using added mass. All materials of submerged racks and their support frame are made of austenitic stainless steel to prevent the corrosion. To evaluate the structural integrity of these racks and their support frame, the response spectrum analysis (RSA) and response time history analysis have been performed under the seismic loads of OBE (Operating Basis Earthquake) and SSE (Safe Shutdown Earthquake) by using ANSYS software. In addition, the possibility of impact between the side wall of the pool and the support frame is investigated by using a nonlinear time history analysis considering the structural nonlinearity such as the contact and the friction problem. The analysis results show that the maximum stress values of these racks and their support frame under the seismic loads are within the specified code limits. Since the sliding distance calculated from the nonlinear time history analysis is less than the gap, the impact does not occur. It is confirmed that those cannot be overturned but slide under an SSE event. Therefore, any damage on the structural integrity is not expected when those are installed and utilized in the pool.


2018 ◽  
Vol 149 ◽  
pp. 02035
Author(s):  
Oumnia Elmrabet ◽  
Hasnae Boubel ◽  
El Mehdi Echebba ◽  
Mohamed Rougui ◽  
Ouadia Mouhat

The current performance-based seismic assessment procedure can be computationally intensive as it requires many time history analyses (THA) each requiring time intensive post-processing of results. Time history analysis is a part of structural analysis and is the calculation of the response of a structure to any earthquake. It is one of the main processes of structural design in regions where earthquakes are prevalent. The objective of this study is to evaluate the seismic performance of embankment dam located on the Oued RHISS in the Province of AL HOCEIMA using the THA method. To monitor structural behavior, the seismic vulnerability of structure is evaluated under real earthquake records with considering the soil-structure-fluide interaction. In this study, a simple assistant program is developed for implementing earthquake analyses of structure with ANSYS, ground acceleration–time history data are used for seismic analysis and dynamic numerical simulations were conducted to study and identify the total response of the soil-structure system.


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