scholarly journals Numerical simulation and experimental validation of ductile tearing in A106 Gr. B piping system under simulated seismic loading conditions

2018 ◽  
Vol 233 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Hyun-Suk Nam ◽  
Gyo-Geun Youn ◽  
Jong-Min Lee ◽  
Hune-Tae Kim ◽  
Yun-Jae Kim
Keyword(s):  
Loading Condition ◽  
Experimental Validation ◽  
Damage Model ◽  
Time History ◽  
Seismic Loading ◽  
Piping System ◽  
Fracture Toughness Test ◽  
Ductile Tearing ◽  
History Analysis ◽  
Dynamic Time

This work presents finite element ductile tearing simulation and experimental validation of a piping system with a circumferential surface cracked (SC) A106 Gr. B pipe under simulated seismic loading condition. The damage model for simulation is based on the multiaxial fracture strain energy. The parameters in the damage model are determined from tensile and fracture toughness test results under the monotonic loading condition. For the system dynamic time history analysis, the Rayleigh damping model is employed. For cyclic constitutive equations, two models were considered to confirm its sensitivity. Predicted crack initiation and ductile tearing agree well with the experimental results.

Response Law and Influencing Factors of the Soil under Action of Pile Driving Vibration Based on Midas/GTS

2013 ◽  
Vol 353-356 ◽  
pp. 979-983
Author(s):  
Dong Zhang ◽  
Jing Bo Su ◽  
Hui De Zhao ◽  
Hai Yan Wang
Keyword(s):  
Damping Ratio ◽  
Large Diameter ◽  
Time History ◽  
Pile Driving ◽  
Analysis Model ◽  
Vibration Load ◽  
History Analysis ◽  
Study Results ◽  
Propagation Law ◽  
Dynamic Time

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.

scholarly journals Seismic Performance of Multistorey RC Frame Building With The Soft Storey and Masonry Infill

2021 ◽  
pp. 650-656
Author(s):  
Kugan K ◽  
Mr. Nandha Kumar P ◽  
Premalath J
Keyword(s):  
Time History ◽  
Seismic Loading ◽  
Rc Frame ◽  
Base Shear ◽  
Maximum Displacement ◽  
Soft Storey ◽  
Masonry Infills ◽  
Frame Building ◽  
History Analysis ◽  
Rc Frame Building

In this study, four geometrically similar frames having different configurations of masonry infills, has been investigated. In this article attempts are made to explain the factors that impact the soft storey failure in a building are compared with different type of infill. That is Four models like RC bare frame, RC frame with brick mansonry infill, RC frame with brick infill in all the storeys exept the firstsoft storey, RC frame with inverted V bracing in the soft storey. Time history analysis has been carried out for a G+8 multistoried building to study the soft storey effect at different floor levels using E tabs software. The behavior of RC framed building with soft storey under seismic loading has been observed in terms of maximum displacement ,maximum storey drift, base shear and storey stiffness as considered structure.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 2 — Application of CCFS Method to the Multiply Supported Systems

2014 ◽  
Author(s):  
Koichi Tai ◽  
Keisuke Sasajima ◽  
Shunsuke Fukushima ◽  
Noriyuki Takamura ◽  
Shigenobu Onishi
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Time History ◽  
Piping System ◽  
History Analysis ◽  
Piping Systems ◽  
Isolation Systems ◽  
Seismic Isolation Systems

This paper provides a part of series of “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Paper is focused on the seismic evaluation method of the multiply supported systems, as the one of the design methodology adopted in the equipment and piping system of the seismic isolated nuclear power plant in Japan. Many of the piping systems are multiply supported over different floor levels in the reactor building, and some of the piping systems are carried over to the adjacent building. Although Independent Support Motion (ISM) method has been widely applied in such a multiply supported seismic design of nuclear power plant, it is noted that the shortcoming of ignoring correlations between each excitations is frequently misleaded to the over-estimated design. Application of Cross-oscillator, Cross-Floor response Spectrum (CCFS) method, proposed by A. Asfura and A. D. Kiureghian[1] shall be considered to be the excellent solution to the problems as mentioned above. So, we have introduced the algorithm of CCFS method to the FEM program. The seismic responses of the benchmark model of multiply supported piping system are evaluated under various combination methods of ISM and CCFS, comparing to the exact solutions of Time History analysis method. As the result, it is demonstrated that the CCFS method shows excellent agreement to the responses of Time History analysis, and the CCFS method shall be one of the effective and practical design method of multiply supported systems.

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

2017 ◽  
Author(s):  
Jong-Sung Kim ◽  
Suk-Hyun Lee ◽  
Hyeong Do Kweon
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Seismic Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Design Basis ◽  
History Analysis ◽  
Study Results ◽  
Transition Length ◽  
Dynamic Time

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.

Ductile Tearing Simulation of Circumferential Cracked Pipe Under Cyclic Loading Using Damage Criteria Determined by Monotonic Pipe Test Data

2018 ◽  
Author(s):  
Jin-Ha Hwang ◽  
Gyo-Geun Youn ◽  
Naoki Miura ◽  
Yun-Jae Kim
Keyword(s):  
Fracture Toughness ◽  
Cyclic Loading ◽  
Ductile Fracture ◽  
Test Data ◽  
Strain Energy ◽  
Fracture Strain ◽  
Damage Model ◽  
Fracture Toughness Test ◽  
Ductile Tearing ◽  
Damage Criteria

To evaluate the structural integrity of nuclear power plant piping, it is important to predict ductile tearing of circumferential cracked pipe from the view point of Leak-Before-Break concept under seismic conditions. CRIEPI (Central Research Institute of Electric Power Industry) conducted fracture test on Japanese carbon steel (STS410) circumferential through-wall cracked pipes under monotonic or cyclic bending load in room temperature. Cyclic loading test conducted variable experimental conditions considering effect of stress ratio and amplitude. In the previous study, monotonic fracture pipe test was simulated by modified stress-strain ductile damage model determined by C(T) specimen fracture toughness test. And, ductile fracture of pipe under cyclic loading simulated using damage criteria based on fracture strain energy from C(T) specimen test data. In this study, monotonic pipe test result is applied to determination of damage model based on fracture strain energy, using finite element analysis, without C(T) specimen fracture toughness test. Ductile fracture of pipe under variable cyclic loading conditions simulates using determined fracture energy damage model from monotonic pipe test.

Dynamic Analysis of Frame-Support-Wall Structure with Openings on Floor

2011 ◽  
Vol 243-249 ◽  
pp. 1401-1404
Author(s):  
Yan Xia Ye ◽  
Jing Zhao
Keyword(s):  
Finite Element ◽  
Good Condition ◽  
Time History ◽  
3D Models ◽  
Mode Analysis ◽  
Wall Structure ◽  
Entire Structure ◽  
History Analysis ◽  
Dynamic Time ◽  
Support Wall

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%.

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.

Determination of structural irregularity limits

2009 ◽  
Vol 42 (4) ◽  
pp. 288-301 ◽  
Author(s):  
Vinod K. Sadashiva ◽  
Gregory A. MacRae ◽  
Bruce L. Deam
Keyword(s):  
Time History ◽  
Static Method ◽  
Simple Analysis ◽  
Floor Level ◽  
Analysis Techniques ◽  
Regular Structures ◽  
Irregular Structures ◽  
History Analysis ◽  
Interstorey Drift ◽  
Dynamic Time

Structures may be irregular due to non-uniform distributions of mass, stiffness, strength or due to their structural form. For regular structures, simple analysis techniques such as the Equivalent Static Method, have been calibrated against advanced analysis methods, such as the Inelastic Dynamic Time-History Analysis. Most worldwide codes allow simple analysis techniques to be used only for structures which satisfy regularity limits. Currently, such limits are based on engineering judgement and lack proper calibration. This paper describes a simple and efficient method for quantifying irregularity limits. The method is illustrated on 3, 5, 9 and 15 storey models of shear-type structures, assumed to be located in Wellington, Christchurch and Auckland. They were designed in accordance with the Equivalent Static Method of NZS 1170.5. Regular structures were defined to have constant mass at every floor level and were either designed to produce constant interstorey drift ratio at all the floors simultaneously or to have a uniform stiffness distribution over their height. Design structural ductility factors of 1, 2, 4 and 6, and target (design) interstorey drift ratios ranging between 0.5% and 3% were used in this study. Inelastic dynamic time-history analysis was carried out by subjecting these structures to a suite of code design level earthquake records. Irregular structures were created with floor masses of magnitude 1.5, 2.5, 3.5 and 5 times the regular floor mass. These increased masses were considered separately at the first floor level, mid-height and at the roof. The irregular structures were designed for the same drifts as the regular structures. The effect of increased mass at the top or bottom of the structure tended to increase the median peak drift demands compared to regular structures for the record suite considered. When the increased mass was present at the mid-height, the structures generally tended to produce lesser drift demands than the corresponding regular structures. A simple equation was developed to estimate the increase in interstorey drift due to mass irregularity. This can be used to set irregularity limits.

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