There is considerable interest in high fidelity simulation of both single phase incompressible flows and multiphase flows. Most commonly applied numerical methods include finite difference, finite volume, finite element and spectral methods. All of these methods attempt to capture the flow details by solving the Navier–Stokes equations. Challenges of solving the Navier–Stokes single phase incompressible flows include the non-locality of the pressure gradient, non-linearity of the advection term and handling the pressure-velocity coupling. Multiphase flow computations pose additional challenges, such as property and flow variable discontinuities at the interface, whose location and orientation is not known a priori. Further, capturing/tracking of the multiphase interface requires solution of an additional advection equation. Recently, the lattice Boltzmann method has been applied to compute fluid dynamics simulations both for single and multiphase configurations; it is considered a modern CFD approach with improved accuracy and performance. Specifically, we employ a multiple-relaxation time (MRT) technique for the collision term on a D3Q27 lattice. The multiphase interface is captured using the phase-field approach of Allen-Cahn. Test cases include lid driven cavity, vortex shedding for a double backward facing step, Rayleigh Taylor instability, Enright’s deformation test and rising bubble in an infinite domain. These test cases validate different aspects of the single and multiphase model, so that the results can be interpreted with confidence that the underlying computational framework is sufficiently accurate.
{"title":"Computations of Single and Multiphase Flows Using a Lattice Boltzmann Solver","authors":"M. Akhtar, H. C. Love","doi":"10.1115/pvp2019-93817","DOIUrl":"https://doi.org/10.1115/pvp2019-93817","url":null,"abstract":"\u0000 There is considerable interest in high fidelity simulation of both single phase incompressible flows and multiphase flows. Most commonly applied numerical methods include finite difference, finite volume, finite element and spectral methods. All of these methods attempt to capture the flow details by solving the Navier–Stokes equations. Challenges of solving the Navier–Stokes single phase incompressible flows include the non-locality of the pressure gradient, non-linearity of the advection term and handling the pressure-velocity coupling. Multiphase flow computations pose additional challenges, such as property and flow variable discontinuities at the interface, whose location and orientation is not known a priori. Further, capturing/tracking of the multiphase interface requires solution of an additional advection equation. Recently, the lattice Boltzmann method has been applied to compute fluid dynamics simulations both for single and multiphase configurations; it is considered a modern CFD approach with improved accuracy and performance. Specifically, we employ a multiple-relaxation time (MRT) technique for the collision term on a D3Q27 lattice. The multiphase interface is captured using the phase-field approach of Allen-Cahn. Test cases include lid driven cavity, vortex shedding for a double backward facing step, Rayleigh Taylor instability, Enright’s deformation test and rising bubble in an infinite domain. These test cases validate different aspects of the single and multiphase model, so that the results can be interpreted with confidence that the underlying computational framework is sufficiently accurate.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124213291","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}
Yujie Zhao, Min Xu, Chunxiao Li, Bin Zhou, Xiao-hua He, Chang-yu Zhou
Cylindrical shell structure is widely used in pressure vessels. In this paper, the orthotropic cylindrical shell structure is analyzed based on the theory of elastoplastic mechanics and the Hill48 yield criterion, the elastoplastic limit load expression of the orthotropic cylindrical shell and the corresponding three-dimensional stress formulas at different stages are obtained. The effect of the radius ratio and the yield strength ratio on the elastic limit load and plastic limit load of the cylindrical shell are also discussed. Finally, the orthotropic cylindrical shell structure is simulated by finite element method, the numerical results verify the correctness of the analytical solutions.
{"title":"Elastoplastic Solution and Limit Load Analysis of Orthotropic Cylindrical Shell Subjected to Internal Pressure","authors":"Yujie Zhao, Min Xu, Chunxiao Li, Bin Zhou, Xiao-hua He, Chang-yu Zhou","doi":"10.1115/pvp2019-93382","DOIUrl":"https://doi.org/10.1115/pvp2019-93382","url":null,"abstract":"\u0000 Cylindrical shell structure is widely used in pressure vessels. In this paper, the orthotropic cylindrical shell structure is analyzed based on the theory of elastoplastic mechanics and the Hill48 yield criterion, the elastoplastic limit load expression of the orthotropic cylindrical shell and the corresponding three-dimensional stress formulas at different stages are obtained. The effect of the radius ratio and the yield strength ratio on the elastic limit load and plastic limit load of the cylindrical shell are also discussed. Finally, the orthotropic cylindrical shell structure is simulated by finite element method, the numerical results verify the correctness of the analytical solutions.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129132713","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}
Coke drums are subjected to severe thermal cycling with the skirt to shell connection weld being vulnerable to fatigue cracking. It is essential this connection is well designed to ensure a long life before repairs are inevitably required. Much has been written on coke drum skirt design with the aim of reducing the thermal stresses and strains encountered at the skirt connection weld, some designs have removed the weld completely allowing the drum to sit in an “egg-in-cup” arrangement. This paper includes a short literature review discussing Coke drum skirt designs and explains skirt behaviour during the drum cycle that results in eventual skirt cracking. A case study is reviewed in detail for a new pair of coke drums, where the predicted fatigue life of the chosen welded connection is assessed using axisymmetric, quarter symmetry and half symmetry finite element analysis supported by thermocouple data. The optimised design focuses on a conventional tangential design where the effects of the essential variables such as skirt thickness, skirt connection location, skirt-to head-gap and slot design (length, location & spacing) have been modelled and optimised to obtain a skirt design that produces the longest fatigue life for the intended duty cycle. Coke drum skirts must be installed onto the shell to exacting tolerances during manufacture to ensure concentricity and minimal gap between the skirt and shell. A brief overview of how this is achieved will be presented.
{"title":"A Review of Optimising the Design of a New Coke Drum Skirt","authors":"A. Berry, W. Brown, A. Seijas, Sarah Cook","doi":"10.1115/pvp2019-93135","DOIUrl":"https://doi.org/10.1115/pvp2019-93135","url":null,"abstract":"\u0000 Coke drums are subjected to severe thermal cycling with the skirt to shell connection weld being vulnerable to fatigue cracking. It is essential this connection is well designed to ensure a long life before repairs are inevitably required. Much has been written on coke drum skirt design with the aim of reducing the thermal stresses and strains encountered at the skirt connection weld, some designs have removed the weld completely allowing the drum to sit in an “egg-in-cup” arrangement. This paper includes a short literature review discussing Coke drum skirt designs and explains skirt behaviour during the drum cycle that results in eventual skirt cracking. A case study is reviewed in detail for a new pair of coke drums, where the predicted fatigue life of the chosen welded connection is assessed using axisymmetric, quarter symmetry and half symmetry finite element analysis supported by thermocouple data. The optimised design focuses on a conventional tangential design where the effects of the essential variables such as skirt thickness, skirt connection location, skirt-to head-gap and slot design (length, location & spacing) have been modelled and optimised to obtain a skirt design that produces the longest fatigue life for the intended duty cycle. Coke drum skirts must be installed onto the shell to exacting tolerances during manufacture to ensure concentricity and minimal gap between the skirt and shell. A brief overview of how this is achieved will be presented.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114167452","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}
Researchers at Northrop Grumman Innovation Systems (NGIS) have been pursuing the application of additive manufacturing (AM) technology in pressure vessel manufacture for several years. We gained significant insight after the design, analysis, fabrication, and qualification of a 1.8 liter propellant tank with additive manufactured shell in 2017. A Space Propulsion 2018 summary paper titled Additive Manufactured Pressure Vessel Shell included a description of the research and its development progress as of May 2018. Importantly, the authors discussed several items for further examination, including developing a material data base, developing fracture inspection techniques, developing fracture data to facilitate fracture analyses, assessing consistency in material properties, and examining material shedding. In this summary paper, we review the continuing AM research and development (R&D) activities within NGIS and provide a progress update. The summary paper has three sections. Section 1 contains program background and a description of the evolving NGIS R&D program. In Section 2, we present a progress update. In Section 3, we conclude with a review of our vision towards the implementation of AM technology in space borne pressure vessel manufacture.
{"title":"Additive Manufactured Pressure Vessel Development: An Update","authors":"W. Tam, Kamil Wlodarczyk, J. Hudak","doi":"10.1115/pvp2019-94033","DOIUrl":"https://doi.org/10.1115/pvp2019-94033","url":null,"abstract":"\u0000 Researchers at Northrop Grumman Innovation Systems (NGIS) have been pursuing the application of additive manufacturing (AM) technology in pressure vessel manufacture for several years. We gained significant insight after the design, analysis, fabrication, and qualification of a 1.8 liter propellant tank with additive manufactured shell in 2017. A Space Propulsion 2018 summary paper titled Additive Manufactured Pressure Vessel Shell included a description of the research and its development progress as of May 2018. Importantly, the authors discussed several items for further examination, including developing a material data base, developing fracture inspection techniques, developing fracture data to facilitate fracture analyses, assessing consistency in material properties, and examining material shedding.\u0000 In this summary paper, we review the continuing AM research and development (R&D) activities within NGIS and provide a progress update. The summary paper has three sections. Section 1 contains program background and a description of the evolving NGIS R&D program. In Section 2, we present a progress update. In Section 3, we conclude with a review of our vision towards the implementation of AM technology in space borne pressure vessel manufacture.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115166785","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}
A new fatigue analysis method was developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society JWES). If the new design fatigue curves are incorporated into the Environmental Fatigue Evaluation Method of the Japan Society of Mechanical Engineers (JSME), the environmental fatigue analysis can be optimized. The Subgroup on Fatigue Evaluation of the Subcommittee on Nuclear Power in the Main Committee on Power Generation Facility Codes in the JSME is reviewing the new design fatigue curves to incorporate into the JSME Environmental Fatigue Evaluation Method. This paper discuss the new design fatigue curves which is under review.
{"title":"Study on Incorporation of a New Design Fatigue Curve Into the JSME Environmental Fatigue Evaluation Method","authors":"S. Asada, Shengde Zhang, M. Takanashi, Y. Nomura","doi":"10.1115/pvp2019-93273","DOIUrl":"https://doi.org/10.1115/pvp2019-93273","url":null,"abstract":"\u0000 A new fatigue analysis method was developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society JWES). If the new design fatigue curves are incorporated into the Environmental Fatigue Evaluation Method of the Japan Society of Mechanical Engineers (JSME), the environmental fatigue analysis can be optimized. The Subgroup on Fatigue Evaluation of the Subcommittee on Nuclear Power in the Main Committee on Power Generation Facility Codes in the JSME is reviewing the new design fatigue curves to incorporate into the JSME Environmental Fatigue Evaluation Method. This paper discuss the new design fatigue curves which is under review.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123791640","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}
A summary of testing related to bolt relaxation, which occurs at temperatures above 230°C (450°F) was presented in a previous paper. The work has since been extended to include lower temperature data for common bolting materials. This paper provides a summary of the additional work performed and further observations regarding the acceptable design limits for A193-B7 and A193-B7M bolt materials. In addition, a conclusion regarding the recommendations made in API RP751 comparing A193-B7 and A193-B7M relaxation is made.
{"title":"An Update on Quantifying Bolt Relaxation During High Temperature Operation","authors":"W. Brown, Nathan Knight","doi":"10.1115/pvp2019-93872","DOIUrl":"https://doi.org/10.1115/pvp2019-93872","url":null,"abstract":"\u0000 A summary of testing related to bolt relaxation, which occurs at temperatures above 230°C (450°F) was presented in a previous paper. The work has since been extended to include lower temperature data for common bolting materials. This paper provides a summary of the additional work performed and further observations regarding the acceptable design limits for A193-B7 and A193-B7M bolt materials. In addition, a conclusion regarding the recommendations made in API RP751 comparing A193-B7 and A193-B7M relaxation is made.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115058352","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}
T. Matsumiya, Daniel Garcia-Rodriguez, A. Nebu, N. Takamura
In this work an evaluation method for local thermal stresses on class 1 piping due to U-shaped lugs is presented. First, a three-dimensional finite element analysis (3D-FEA) is used to perform a thermal transient evaluation, obtaining the time-dependent temperature distribution of a realistic range of pipe-lug systems. These results are then used as an input for both a structural 3D-FEA and the corresponding thermal stress term in Non-Mandatory Appendix Y [1]. It was seen that the formula in Appendix-Y cannot account for the thermal stresses obtained through the detailed FEA evaluation. A parameter study using a simplified two-dimensional (2D) FEA approach, shows that the localized thermal stresses due to lugs are significantly affected by: (1) pipe-to-lug thickness ratio, (2) distance between adjacent lugs, and (3) lug height. A set of correction coefficients depending on these parameters is therefore proposed. When applying the proposed correction coefficients to the Appendix Y method, adequately conservative (when compared with 3D FEA results) stresses can be obtained. Since these correction coefficients can be obtained from simple geometric considerations, the proposed method successfully accounts for the complex lug-to-lug interaction while retaining the simplicity of the original Appendix Y approach.
{"title":"A Simplified Thermal Load Evaluation Method for Localized Lug Stresses Beyond Sec. III Appendix-Y","authors":"T. Matsumiya, Daniel Garcia-Rodriguez, A. Nebu, N. Takamura","doi":"10.1115/pvp2019-93127","DOIUrl":"https://doi.org/10.1115/pvp2019-93127","url":null,"abstract":"\u0000 In this work an evaluation method for local thermal stresses on class 1 piping due to U-shaped lugs is presented.\u0000 First, a three-dimensional finite element analysis (3D-FEA) is used to perform a thermal transient evaluation, obtaining the time-dependent temperature distribution of a realistic range of pipe-lug systems. These results are then used as an input for both a structural 3D-FEA and the corresponding thermal stress term in Non-Mandatory Appendix Y [1]. It was seen that the formula in Appendix-Y cannot account for the thermal stresses obtained through the detailed FEA evaluation.\u0000 A parameter study using a simplified two-dimensional (2D) FEA approach, shows that the localized thermal stresses due to lugs are significantly affected by: (1) pipe-to-lug thickness ratio, (2) distance between adjacent lugs, and (3) lug height. A set of correction coefficients depending on these parameters is therefore proposed.\u0000 When applying the proposed correction coefficients to the Appendix Y method, adequately conservative (when compared with 3D FEA results) stresses can be obtained. Since these correction coefficients can be obtained from simple geometric considerations, the proposed method successfully accounts for the complex lug-to-lug interaction while retaining the simplicity of the original Appendix Y approach.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"103 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120819048","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}
The aim of this study is to propose the damage model on the basis of the mechanism for ductile fracture related to void growth and applicable to ductile fracture assessment for steels. In order to determine damage evolution law, void growth behavior in the material was investigated by elasto-plastic finite element analyses using unit cell model with an initial void. From the results of the unit cell analyses, it was evident that a void in unit cell grew nonlinearly with increasing applied macroscopic strain. Moreover, the relationships between normalized void volume fraction and normalized strain by each critical value corresponding to crack initiation were independent of stress-strain relationship of material and stress triaxiality state. Based on this characteristic associated with void growth, damage evolution law representing nonlinear damage accumulation was derived. Then, using the damage evolution law, ductile damage model reflecting void growth behavior and ductility of material was proposed. For validation and application of the proposed damage model, ductile crack growth tests using bend specimens with a machined notch or a fatigue pre-crack were conducted for low carbon steel. The proposed damage model was implemented in finite element analyses and ductile crack growth simulations were performed for each bending test. Then, it was shown that the proposed model could accurately predict ductile crack growth resistance from machined notch root and fatigue pre-crack tip (R-curves) and the validity and applicability of proposed damage model to cracked components could be confirmed.
{"title":"Proposal of Ductile Damage Model Based on Unit Cell Analysis for Prediction of Ductile Crack Growth Resistance of Cracked Component","authors":"Takehisa Yamada, M. Ohata","doi":"10.1115/pvp2019-93098","DOIUrl":"https://doi.org/10.1115/pvp2019-93098","url":null,"abstract":"\u0000 The aim of this study is to propose the damage model on the basis of the mechanism for ductile fracture related to void growth and applicable to ductile fracture assessment for steels. In order to determine damage evolution law, void growth behavior in the material was investigated by elasto-plastic finite element analyses using unit cell model with an initial void. From the results of the unit cell analyses, it was evident that a void in unit cell grew nonlinearly with increasing applied macroscopic strain. Moreover, the relationships between normalized void volume fraction and normalized strain by each critical value corresponding to crack initiation were independent of stress-strain relationship of material and stress triaxiality state. Based on this characteristic associated with void growth, damage evolution law representing nonlinear damage accumulation was derived. Then, using the damage evolution law, ductile damage model reflecting void growth behavior and ductility of material was proposed.\u0000 For validation and application of the proposed damage model, ductile crack growth tests using bend specimens with a machined notch or a fatigue pre-crack were conducted for low carbon steel. The proposed damage model was implemented in finite element analyses and ductile crack growth simulations were performed for each bending test. Then, it was shown that the proposed model could accurately predict ductile crack growth resistance from machined notch root and fatigue pre-crack tip (R-curves) and the validity and applicability of proposed damage model to cracked components could be confirmed.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125845234","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}
Tim J. Nowicki, D. Suddaby, Joshua J. Donovan, A. Conn, M. Paharia
Preoperational testing of the first AP1000® pressurized water reactors took place in the fall and winter of 2016. This Hot Functional Testing (HFT) included observation of vibrations throughout the piping systems, and is required to be successfully completed before fuel load. During HFT, flow through the hot leg passes many piping intersections where instabilities such as vortex shedding create pressure pulsations. Coupling of the vortex shedding frequency and natural acoustic frequency of the piping sidebranch may lead to acoustic resonance of the system. This resonance condition is understood, but difficult to predict; therefore, the HFT plan included screening for such conditions based on ASME Operation and Maintenance of Nuclear Power Plants vibration monitoring group (VMG). Vibration was observed in the Automatic Depressurization System (ADS) branch off the reactor coolant system hot leg that was potentially in a resonant condition. This paper details the identification, characterization, and analysis of the ADS vibration observed during HFT. Additional instrumentation was employed and data were gathered at varying conditions to determine the nature and extent of the vibrations. Demonstration of acceptable vibration levels in the ADS system was a key engineering accomplishment for AP1000® fuel load.
{"title":"ADS-4 Pipe Vibration Evaluation During AP1000® Preoperational Testing","authors":"Tim J. Nowicki, D. Suddaby, Joshua J. Donovan, A. Conn, M. Paharia","doi":"10.1115/pvp2019-93282","DOIUrl":"https://doi.org/10.1115/pvp2019-93282","url":null,"abstract":"\u0000 Preoperational testing of the first AP1000® pressurized water reactors took place in the fall and winter of 2016. This Hot Functional Testing (HFT) included observation of vibrations throughout the piping systems, and is required to be successfully completed before fuel load.\u0000 During HFT, flow through the hot leg passes many piping intersections where instabilities such as vortex shedding create pressure pulsations. Coupling of the vortex shedding frequency and natural acoustic frequency of the piping sidebranch may lead to acoustic resonance of the system. This resonance condition is understood, but difficult to predict; therefore, the HFT plan included screening for such conditions based on ASME Operation and Maintenance of Nuclear Power Plants vibration monitoring group (VMG).\u0000 Vibration was observed in the Automatic Depressurization System (ADS) branch off the reactor coolant system hot leg that was potentially in a resonant condition. This paper details the identification, characterization, and analysis of the ADS vibration observed during HFT. Additional instrumentation was employed and data were gathered at varying conditions to determine the nature and extent of the vibrations. Demonstration of acceptable vibration levels in the ADS system was a key engineering accomplishment for AP1000® fuel load.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125899779","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}
Over the past two years, the accuracy and repeatability of equipment used to assemble bolted flanged joints have been studied, and progress has been reported in past papers. One of the findings has been that pneumatic torque wrenches demonstrated a broader plus/minus range on bolt stress from the targeted value (e.g., lack of accuracy) than manual or hydraulic torque wrenches. What was notable, however, was that the repeatability of the bolt stress that was achieved did remain consistent with the other types of torque wrenches. Since the repeatability has been shown to be consistent, attention has turned to investigating and determining the reason for the perceived lack of accuracy. One aspect that might account for this is the calibration of the pneumatic torque wrenches. This paper outlines and documents the research that has recently taken place to identify the parameters that are key elements in improving the accuracy of pneumatic torque wrenches that might form the basis of development of a standard for calibration of powered torqueing equipment.
{"title":"Further Work on Analyzing Accuracy and Overall Performance of Torque Tools for Assembling Bolted Flanged Joints","authors":"Clay D. Rodery, S. Hamilton, N. Ferguson","doi":"10.1115/pvp2019-93691","DOIUrl":"https://doi.org/10.1115/pvp2019-93691","url":null,"abstract":"\u0000 Over the past two years, the accuracy and repeatability of equipment used to assemble bolted flanged joints have been studied, and progress has been reported in past papers. One of the findings has been that pneumatic torque wrenches demonstrated a broader plus/minus range on bolt stress from the targeted value (e.g., lack of accuracy) than manual or hydraulic torque wrenches. What was notable, however, was that the repeatability of the bolt stress that was achieved did remain consistent with the other types of torque wrenches. Since the repeatability has been shown to be consistent, attention has turned to investigating and determining the reason for the perceived lack of accuracy. One aspect that might account for this is the calibration of the pneumatic torque wrenches.\u0000 This paper outlines and documents the research that has recently taken place to identify the parameters that are key elements in improving the accuracy of pneumatic torque wrenches that might form the basis of development of a standard for calibration of powered torqueing equipment.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117168978","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}
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