Volume 8: Seismic Engineering最新文献

{"title":"Investigation of Method of Elasto-Plastic Analysis for Piping System Excited by Multi-Direction Input","authors":"Takuro Kabaya, N. Kojima, M. Arai, S. Hirouchi, M. Bando","doi":"10.1115/PVP2018-84468","DOIUrl":"https://doi.org/10.1115/PVP2018-84468","url":null,"abstract":"This paper provides investigation on method of an elasto-plastic analysis for practical seismic design of nuclear piping systems, which are excited by multi-direction input.\u0000 The Japan Society of Mechanical Engineers (JSME) established a task group to develop an elasto-plastic analysis method for nuclear piping systems, and prepared a case example code proposal for JSME.[1],[2] Our studies in past (ASME PVP2016-63186[3] and ASME PVP2017-65341[4]) were implemented on tests with unidirectional excitation using simple piping systems. In order to examine the applicability of the proposed case example code for JSME in piping of actual systems, it is necessary to examine cases in which there is multidirectional input excitation in piping systems in scales comparable to those of the piping in actual systems. We therefore conducted an analytical examination on demonstration of “the ultimate strength of piping system,” which was implemented at NUPEC. [5]\u0000 We confirmed in the results of analytical examination that the strain range could be calculated at precision nearly equivalent to our examinations in the past, and that the draft code case was applicable. However, we also found a problem which needs to be solved.\u0000 In addition, we were able to confirm that the local damping increase caused by the elasto-plastic behavior of the elbow which was subject to examination in this study was 1% or larger.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116620185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of JSME Seismic Code Case by Elastic-Plastic Response Analysis to Practical Piping System","authors":"Akihito Otani, Satoru Kai, N. Kaneko, Tomoyoshi Watakabe, M. Ando, K. Tsukimori","doi":"10.1115/PVP2018-84079","DOIUrl":"https://doi.org/10.1115/PVP2018-84079","url":null,"abstract":"A Code Case in the framework of JSME Nuclear Codes and Standards is being developed to incorporate a seismic design evaluation methodology for piping by means of advanced elastic-plastic response analysis methods and strain-based fatigue criteria. The Code Case as an alternative seismic design rule over the current rule will provide a more rational seismic design evaluation than the current criteria.\u0000 This paper demonstrates an application result of the JSME Seismic Code Case to an actual complex piping system. The secondary coolant piping system of Japanese Fast Breeder Reactor, Monju, was selected as a representative of the complex piping systems. The elastic-plastic time history analysis for the piping system was performed and the piping system has been evaluated according to the JSME Seismic Code Case. The evaluation by the Code Case provides a reasonable result in terms of the piping fatigue evaluation that governs seismic integrity of piping systems. Moreover, it is found that the supporting forces and the response accelerations of the piping system obtained by the elastic-plastic response analysis also become more rational results than those with the current elastic response analysis. The contradiction of two requirements in piping design, flexibility for thermal expansion and rigidity for seismic response, can be effectively relaxed by use of the Code Case being developed.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125244033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Predictive Evaluation Method of Nonlinear Sloshing Wave Height of Cylindrical Tanks: Part 1 — Shaking Table Test Results and Verification Results of Analytical Method for Nonlinear Sloshing","authors":"H. Morita, Tomoshige Takata, H. Madokoro, H. Sago, Hisatomo Murakami, Shinobu Yokoi, Tomohiko Yamamoto","doi":"10.1115/PVP2018-84416","DOIUrl":"https://doi.org/10.1115/PVP2018-84416","url":null,"abstract":"When cylindrical tanks installed on the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage to the tank roof or outflow of internal liquid. Therefore, it is important to predict the wave height of sloshing generated by an earthquake input.\u0000 Sloshing is vibration of the free liquid surface, and when the sloshing wave height is small, it can be approximated with a linear vibration model. In that case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under an earthquake input. However, when the sloshing wave height increases and the sloshing becomes nonlinear, it is necessary to evaluate the wave height using other methods such as numerical analysis.\u0000 Taking into consideration that design earthquake levels tend to increase and the use of seismic isolation mechanisms has continued to spread in recent years, the amplitude of the long-period components of an earthquake input which act on cylindrical tanks may also increase. Therefore, although the evaluation of nonlinear sloshing wave height is important, there are few examples which quantitatively evaluate the wave height of nonlinear sloshing.\u0000 The purpose of this study is to construct a simple evaluation technique of a nonlinear sloshing wave height of cylindrical tanks. In this study, the shaking table test using the small cylindrical tank for studying the behavior of nonlinear sloshing was carried out. Furthermore, verification of the flow-analysis technique described by previous report (PVP2017-65313) was carried out by comparing with test results. As a result, the data for constructing an evaluation technique has been acquired. Moreover, the validity of the flow-analysis technique was has been verified.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127343140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Test Result of Motor-Operated Butterfly Valve Actuators for Nuclear Power Plant","authors":"N. Kojima, Y. Tsutsumi, Kazuyoshi Yonekura, K. Nishino, Yukio Watanabe, S. Kumagai, Hiroyuki Kamino","doi":"10.1115/PVP2018-84219","DOIUrl":"https://doi.org/10.1115/PVP2018-84219","url":null,"abstract":"Seismic tests were carried out to confirm the operability limit acceleration for a standard motor-operated butterfly valve actuator in three excitation directions. Based on the results, seismic brackets that can operate valves even in three directions at 20 × 9.8 m/s2 or more were designed in three representative models. For the model subjected to the seismic test, we mounted the designed seismic bracket and confirmed the operability of the butterfly valve actuator by carrying out vibration tests in three directions at 20 × 9.8 m/s2. We used these results and previously reported motor-operated valve actuator seismic test results to creat a revision (draft) of the earthquake resistance evaluation methods.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121703713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 5 — Influence of Damper Properties on Lifetime","authors":"K. Aida, K. Minagawa, Go Tanaka, S. Fujita","doi":"10.1115/PVP2018-84514","DOIUrl":"https://doi.org/10.1115/PVP2018-84514","url":null,"abstract":"In 2011, Great East Japan Earthquake that is the largest earthquake ever observed in Japan occurred. The earthquake had large energy, long duration and many aftershocks, and coal-fired thermal power plants were damaged by the earthquake [1]. Boiler structures in coal-fired thermal power plants are generally high-rise structures, and boilers are simply suspended from the top of the support structures in order to allow thermal expansion, so boilers easily vibrate [2]. In order to suppress vibration of boilers during earthquakes, stoppers are generally set between boilers and support structures. The stoppers are made of steel, and dissipate vibration energy by plastic deformation. However aseismic requirements for thermal power plants have been increased as a result of the Great East Japan Earthquake. Thus authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP 2017, the basic performance of the proposed damper was presented [3–5]. In this paper, influence of damper properties on lifetime of the damper was investigated by seismic response analyses. In addition, lifetime of dampers for long period and long duration earthquake waves were investigated by seismic response analyses.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130779453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromagnetic Damper Using Brushless DC Motor With Capacitance","authors":"T. Matsuoka","doi":"10.1115/PVP2018-84021","DOIUrl":"https://doi.org/10.1115/PVP2018-84021","url":null,"abstract":"Electromagnetic damper using brushless DC motor was developed. The damper has a ball screw mechanism, and a linear motion is converted into rotational motion. The blushless DC motor was installed in tip of the ball screw shaft, and electrical power was generated when the shaft was rotating. Electrical resistance was inserted into terminal of the motor as delta-connected winding, and capacitances were also inserted in parallel. Theory of the torque was introduced with current limit. Force and displacement curves were measured, and resisting force characteristics were confirmed. Dynamic propertied of the damper was investigated.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133972207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Seismic Design Approach Using Inelastic Dynamic Analysis for Equipment and Piping Systems","authors":"I. Tamura, A. Okubo, Yusuke Minakawa, T. Iijima, Nobuyoshi Goshima, Masanori Amino, Y. Okuda, Shunji Okuma","doi":"10.1115/PVP2018-84126","DOIUrl":"https://doi.org/10.1115/PVP2018-84126","url":null,"abstract":"Securing an adequate seismic margin has been important in safety reviews regarding the seismic design of equipment and piping systems in nuclear power plants, and there exists an increasing need for a more exact method for evaluating seismic margins. To this end, it is reasonable to take into account the reduction of seismic responses resulting from elastoplastic deformation. The authors, therefore, launched a research program to develop an approach to seismic design that uses elastoplastic dynamic analysis for equipment and piping systems. The allowable limit is one of the essential parameters, especially for our approach of using elastoplastic analysis, and was focused on in the program. We studied this approach by utilizing the conventional allowable limit and other potential limits such as the ductility factor. The applicability of the proposed approach was investigated by comparison with the conventional design method. For the investigation, nonlinear time-history analyses producing elastoplastic responses were conducted, and the results were compared with those of the conventional elastic analysis to quantify the response reduction leading to the seismic margin. For the comparison, the authors used three models that simulated a cantilever beam, tank, and core shroud. In this paper, the beam was constructed and applied to the analysis herein. In the next report, the authors will discuss the applicability of the three models. The cantilever beam is the simplest structure among the three models, and it might be useful for obtaining suggestive results from the analysis. The discussion on the beam, therefore, was conducted prior to the other two models, and, in addition, the sensitivity of model parameters such as yielding stress and secant stiffness will be examined in a parametric study using the model. In this paper, we outline the research program and present a scheme for developing the design approach of using elastoplastic analysis. Moreover, calculated analysis results for the cantilever beam are partly reported, and the applicability of the design approach of using elastoplastic analysis is discussed.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115549354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research and Development of Three-Dimensional Isolation System for Sodium-Cooled Fast Reactor: Part 2 — Details of Characteristics for Disc Springs and Oil Dampers on Basis of Full-Scale Loading Tests","authors":"T. Somaki, Tsuyoshi Fukasawa, Takayuki Miyagawa, Tomohiko Yamamoto, Yoshifumi Hibako, Masanari Okamoto, Osamu Noda, F. Ishizuka","doi":"10.1115/PVP2018-84491","DOIUrl":"https://doi.org/10.1115/PVP2018-84491","url":null,"abstract":"Being compatible with the seismic and thermal loads for the large Sodium-cooled Fast Reactor (SFR), the three-dimensional isolation system is inevitable technology. The three-dimensional isolation system consists of the thick rubber bearings, the disc springs and the oil dampers.\u0000 Since the isolation performances on the rubber bearings in the horizontal direction have been revealed by the previous studies [1], the vertical isolation performance and characteristics such as restoring force and damping performance should be clarified by loading tests to build the analytical model. This paper presents these fundamental vertical isolation characteristics obtained by loading tests with full-scaled disc springs and oil dampers. The disc springs as the vertical restoring forces have 700 mm in external diameter and 34 mm in thickness. The oil dampers have the maximum damping force of 2,000 kN at the velocity of 0.25 m/s. The disc spring is one of the largest size, and the oil damper is one of the largest damping capacity in Japan.\u0000 The static loading tests such as incremental cyclic loadings under the supporting load were conducted to investigate the restoring force characteristics for the disc springs. The dynamic loading using sinusoidal waves with varied input frequencies or the seismic response waves obtained by seismic response analysis were conducted to investigate the damping performance for the oil dampers.\u0000 The applicability of the design method and the analytical model for disc springs and oil dampers were demonstrated by the restoring force characteristics obtained from tests.\u0000 It should be noted, this paper is in series from Part 1.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114300708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-Scale Simulation for Particle Damping","authors":"M. Saeki, Mika Bitoh","doi":"10.1115/PVP2018-84544","DOIUrl":"https://doi.org/10.1115/PVP2018-84544","url":null,"abstract":"Particle damping is an effective method of passive vibration control. Although it has been widely used in various structural damping applications, there are some points to be examined. Few studies have focused on the difference in the effectiveness of particle dampers for systems with different natural frequencies. Also, a computational scheme for conducting large-scale simulations has not been established. The authors previously presented some computational methods for predicting large-scale particle damping. The calculations are performed using equivalent large particles instead of the original-size particles. However, the range of the radius of the equivalent large particles for which these methods are effective is still incompletely understood. The objective of this study is to experimentally examine the difference in the effectiveness of particle dampers for systems with different natural frequencies and to investigate the relationship between the radius of the equivalent large particles and the validity of the computational methods.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128120801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Test Analysis Evaluation of Motor-Operated Valve Actuators for Nuclear Power Plant","authors":"N. Kojima, Y. Tsutsumi, Kazuyoshi Yonekura, K. Nishino, Yukio Watanabe, S. Kumagai, Hiroyuki Kamino","doi":"10.1115/PVP2018-84223","DOIUrl":"https://doi.org/10.1115/PVP2018-84223","url":null,"abstract":"The function of motor-operated valves provided in nuclear power plants during an earthquake has been previously evaluated on the basis of seismic test results; however, since the response acceleration has increased with a recent reassessment of standard earthquake ground motions, it is necessary to evaluate their function during high acceleration earthquakes.\u0000 In order to carry out seismic test analysis, we examined the compression characteristics of the gaskets in three kinds of representative valves, in terms of the current load and slide coefficient, by element tests. We created an analysis method using the finite element method which used the gasket’s characteristics, and the result of these analyses could explain the loosing and the amplitude of the bolt connecting force and gasket slipping at the time of excitation to the safety side.\u0000 According to the analysis, the actuator connection part of the motor-operated butterfly valve showed a seismic resistance of 20 × 9.8m/s2 and other parts showed a seismic resistance of 30 × 9.8m/s2.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115969075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}