Volume 8: Seismic Engineering最新文献

{"title":"Verification of the Relation Between the Directions of Control Force and Responses in Active Seismic Isolation Device","authors":"Keigo Nakamura, N. Miura, A. Sone","doi":"10.1115/PVP2018-84446","DOIUrl":"https://doi.org/10.1115/PVP2018-84446","url":null,"abstract":"In this research, the focus is on the energy problem in active vibration control of a seismic isolation device using self-powered active control that regenerates electric power from kinetic energy of vibration system and uses it as control power. In recent years, it is proposed to install semi-active control or active control in an isolated structure to deal with seismic waves of various periods. However, since energy is required for control, there is a problem that the desired response reduction performance cannot be achieved when energy supply is interrupted at the time of a power outage. In our previous device, power is always given to the motor to control, thus power consumption is high. Therefore, the purpose of this research is to propose input method of control force that can reduce control power while keeping base isolation performance by classifying the role of the control force for each control phase and considering various combinations of input control force.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"1 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":"115199402","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":"Appropriate Damping on Seismic Design Analysis for Inelastic Response Assessment of Piping","authors":"Tomoyoshi Watakabe, M. Morishita","doi":"10.1115/PVP2018-84470","DOIUrl":"https://doi.org/10.1115/PVP2018-84470","url":null,"abstract":"The current seismic design rule on piping assumes elastic analysis without the effect of response reduction due to plasticity, although some degree of plasticity is allowed in its allowable limits. Damping for the seismic design analysis is conservatively determined depending on the number of supports and thermal insulation conditions. These conservative assumptions lead to large amount of design margin. Based on such recognition, to provide a more rational seismic design method, a new Code Case for seismic design of piping is now under development in the framework of JSME Nuclear Codes and Standards as an alternative rule to the current design rule. The Code Case provides detailed inelastic analysis with using shell or solid FEA models as a more rational method. Simplified analysis with an additional damping taking the response reduction due to plasticity into account is now under consideration to incorporate the convenience in design. In this study, a series of analysis was made to see the adequacy of the simplified inelastic analysis. Design margins contained in the current design analysis method composed of response spectrum analysis and stress factors was quantitatively assessed in the view point of additional damping.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"48 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":"125425125","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":"Fast Reactor Core Seismic Experiment of Full Scale Single Model of Control Rod","authors":"Akihisa Iwasaki, Shinichiro Matsubara, K. Kawamura, Hidenori Harada, Tomohiko Yamamoto","doi":"10.1115/PVP2018-84471","DOIUrl":"https://doi.org/10.1115/PVP2018-84471","url":null,"abstract":"The control rod guide tube self-stands on the core support plate. The control rod is inserted in the control rod guide tube, and the control rod hangs from the upper structure of the reactor. At scrum in case of an earthquake, the control rod is detached and it sits on the seating structure in the control rod guide tube. The control rod guide tube is raised more easily than the fuel assembly by the vertical differential pressure of the core during operation, because the control rod guide tube is lighter than the fuel assembly. Therefore, it is necessary to restrain the rising of the control rod guide tube. The sleeve dashpot structure, in which a sleeve is attached on the upper surface of the receptacle tube, is employed. Moreover, the control rod guide tube is equipped with the control rod dashpot in order to restrain the vertical movement of the control rod. In case of an earthquake, horizontal vibrational behavior also arises. The horizontal vibration generates friction force in the vertical direction and it restrains the rising. In this seismic evaluation of the control rod guide tube and the control rod, only the vertical motion is taken into consideration because it becomes conservative side against the rising displacement.\u0000 The seismic evaluation of the control rod guide tube is performed in operating condition (the coolant is flowing upward); that of the control rod assembly (the control rod guide tube and the control rod) is performed in shutdown condition (the coolant is not flowing).\u0000 Seismic experiments were performed using a full-scale model of the control rod guide tube and the control rod, vertical excitation and water instead of liquid sodium in the actual plant, to verify the analysis method and to demonstrate the rising restraining effect of the sleeve dashpot and the control rod dashpot. In this study, the rising behavior of the control rod guide tube and the control rod was investigated. The effect of restraining rising by the sleeve dashpot and by the control rod dashpot was confirmed.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"13 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":"121918758","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 2 — Proposal and Examination of Applicability of the Predictive Evaluation Method","authors":"H. Sago, H. Morita, Tomoshige Takata, H. Madokoro, Hisatomo Murakami, Shinobu Yokoi, Tomohiko Yamamoto","doi":"10.1115/PVP2018-84419","DOIUrl":"https://doi.org/10.1115/PVP2018-84419","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 simple evaluation technique of the nonlinear sloshing wave height was proposed based on the study result shown by the 1st report (PVP2018-84416). Moreover, in order to verify the applicability of the proposed evaluation technique, the shaking table test and flow analysis which used the small cylindrical tank were carried out. As a result, the applicability of the proposed evaluation technique has been verified.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"73 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":"127136210","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":"Effect of Static Load Components in Seismic Loading on Gross Plastic Deformation on Structure","authors":"Satoru Kai, Akihito Otani","doi":"10.1115/PVP2018-84415","DOIUrl":"https://doi.org/10.1115/PVP2018-84415","url":null,"abstract":"In general, a seismic load acting on a structure is considered to potentially cause unstable gross plastic deformation that is called as plastic collapse, because the seismic load induce an inertia force on the structure which may act as an external force onto the structure. The past researches by the authors to clarify the characteristic of seismic loads found that the way of the seismic response on the structure is driven by the correlation between the seismic loading and the natural frequency of the structure while only the dynamic loads are acting. On the other hand, existence of relatively large sustained loads such as a dead weight was also recognized to promote an unstable gross plastic deformation in the past experimental studies.\u0000 Based on the previous studies, two factors that are the sustained load level and the correlation other than the dynamic load level are expected to play an important role in determining the dynamic behavior of a structure and potentially governing the failure mode. The several elastic-plastic analyses with an elastic-perfect-plastic (EPP) material property and a simplified structure were conducted in this paper by slightly changing the level of the sustained loads and the dynamic loads. From the analytical results focusing on the ratchet deformations and residual deformations, the level of the sustained load on the structure was found to promote ratcheting behavior on the structure with a specific trend and significantly affect the dynamic behavior at the conceptual conditions which were defined and identified in the past researches.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"1 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":"131007474","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":"Ratcheting Behavior of Pressurized Elbow Pipe After Thermal Aging","authors":"Caiming Liu, Dunji Yu, Xu Chen","doi":"10.1115/PVP2018-84108","DOIUrl":"https://doi.org/10.1115/PVP2018-84108","url":null,"abstract":"In the present work, the effect of thermal aging on ratcheting behaviors of three pressurized elbow pipes after different thermal aging periods was experimentally studied under constant internal pressure and reversed in-plane bending. The elbow pipes were thermal aged for 1000 h and 2000 h at the same aging temperature of 500 centigrade degrees. It is indicated that thermal aging period has a significant effect on elbow pipe’s ratcheting deformation. Chen-Jiao-Kim (CJK) kinematic hardening model was employed to evaluate the ratcheting behaviors of pressured elbow pipes affected by thermal aging.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"78 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":"114786936","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":"Estimation Accuracy of Absolute Maximum Elasto-Plastic Displacements of MDOF Oscillators Based on a Modal Combination Rule With Post-Yielding Modal Properties and Linear Response Spectrum Values","authors":"T. Taniguchi, Yoshihiko Toda, Y. Ono, K. Mukaibo","doi":"10.1115/PVP2018-84237","DOIUrl":"https://doi.org/10.1115/PVP2018-84237","url":null,"abstract":"Taniguchi, et al. [1] developed an analytical method for evaluating the absolute maximum elasto-plastic displacements of multi-degree-of-freedom (MDOF) oscillators under the action of base excitation based on a modal combination. Its essence is that 1) modal frequencies, shapes and damping during yielding of any member of the MDOF oscillators are readily specified by the modal analysis with the secondary stiffness of the members being yielded, 2) assuming that a bilinear hysteresis may describe the force-displacement relationship of each mode, an equivalently linearized system consisting of a single-degree-of-freedom (SDOF) oscillator is introduced to approximate the absolute maximum elasto-plastic displacement of each mode, 3) the absolute maximum elasto-plastic displacement of the MDOF oscillator is evaluated by the Square Root of Sum of Squares rule (SRSS-rule) by combining the maximum elasto-plastic displacement of each mode approximated by the proposed equivalently linearized system. This study first provides small modification in the equivalently linearized system. Then, employing a couple of MDOF oscillators whose spring at arbitrary storey may yield and an accelerogram, the maximum elasto-plastic displacement of the MDOF oscillator is calculated by the proposed method and is compared with that computed by the time history analysis. Their comparison suggests that the proposed method can reasonably evaluate the absolute maximum elasto-plastic displacement of the MDOF oscillator subjected to earthquake excitation as the conventional SRSS-rule does that for the linear MDOF oscillators.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"50 14 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":"124240276","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":"Verification of Mainframe Computer Structure Finite Element Model Under Vibration and Seismic Tests","authors":"B. Notohardjono, S. Canfield, Suraush Q. Khambati, R. Ecker","doi":"10.1115/PVP2018-84200","DOIUrl":"https://doi.org/10.1115/PVP2018-84200","url":null,"abstract":"Shorter development design schedules and increasingly dense product designs create difficult challenges in predicting structural performance of a mainframe computer’s structure. To meet certain certification benchmarks such as the Telcordia Technologies Generic Requirements GR-63-CORE seismic zone 4 test profile, a physical test is conducted. This test will occur at an external location at the end of design cycle on a fully functional and loaded mainframe system. The ability to accurately predict the structural performance of a mainframe computer early in the design cycle is critical in shortening its development time.\u0000 This paper discusses an improved method to verify the finite element analysis results predicting the performance of the mainframe computer’s structure long before the physical test is conducted. Sine sweep and random vibration tests were conducted on the frame structure but due to a limitation of the in-house test capability, only a lightly loaded structure can be tested. Evaluating a structure’s modal stiffness is key to achieving good correlation between a finite element (FE) model and the physical system. This is typically achieved by running an implicit modal analysis in a finite element solver and comparing it to the peak frequencies obtained during physical testing using a sine sweep input. However, a linear, implicit analysis has its limitations. Namely, the inability to assess the internal, nonlinear contact between parts. Thus, a linear implicit analysis may be a good approximation for a single body but not accurate when examining an assembly of bodies where the interaction (nonlinear contact) between the bodies is of significance. In the case of a nonlinear assembly of bodies, one cannot effectively correlate between the test and a linear, implicit finite element model.\u0000 This paper explores a nonlinear, explicit analysis method of evaluating a structure’s modal stiffness by subjecting the finite element model to a vibration waveform and thereafter post processing its resultant acceleration using Fast Fourier Transformation (FFT) to derive the peak frequencies. This result, which takes into account the nonlinear internal contact between the various parts of the assembly, is in line with the way physical test values are obtained. This is an improved method of verification for comparing sine sweep test data and finite element analysis results.\u0000 The final verification of the finite element model will be a successful physical seismic test. The tests involve extensive sequential, uniaxial earthquake testing in both raised floor and non-raised floor environments in all three directions. Time domain acceleration at the top of the frame structure will be recorded and compared to the finite element model. Matching the frequency content of these accelerations will be proof of the accuracy of the finite element model. Comparative analysis of the physical test and the modeling results will be used to refine the mainframe’s structural","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"1 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":"131198807","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":"Pipe Ovalization Prediction for the Pipe-Laying Ocean System","authors":"M. Bartecký, R. Halama","doi":"10.1115/PVP2018-84785","DOIUrl":"https://doi.org/10.1115/PVP2018-84785","url":null,"abstract":"This contribution brings a new insight into pipe cross section ovalisation due to plastic deformation during pipe-lying process to the seabed. Firstly, the influence of material model calibration on ovalization prediction is presented on pure bending case including the Prager model, the Chaboche model and the modified Abdel-Karim–Ohno model. The mechanism responsible for cross section ovalisation was identified as the phenomenon of the accumulation of plastic deformation, the so-called ratcheting. The next part of this contribution presents main results of the pipe-laying process simulation. The pipe cross-section behavior during passing the considered pipe-laying system is studied in detail. A macro based solution makes possible to do a parametric study and to easily apply the offshore standard DNV-OS-F101 in technical practice.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"33 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":"133111792","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 Ultimate State of Filament Winding FRP Pipes Under Bending Force","authors":"Y. Shiogama, N. Kumagai, Y. Ando, T. Kuribayashi","doi":"10.1115/PVP2018-84417","DOIUrl":"https://doi.org/10.1115/PVP2018-84417","url":null,"abstract":"To investigate of ultimate state of filament winding FRP pipe against bending force caused by earthquake, we perform four-point bending test of the FRP pipes with 1.4MPa inner water pressure. Twelve pipes with four different proportions are applied to the test. The test results show that the damaged form and strength depends on the proportion of the pipe. It is considered reasonable to set the allowable bending capacities according to size of the pipes.","PeriodicalId":180537,"journal":{"name":"Volume 8: Seismic Engineering","volume":"11 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":"114546054","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}