The failure mode estimation of essential components in nuclear facilities under beyond design-basis events (BDBEs) is necessary to mitigate the consequences during severe accident conditions. The plastic collapse induced by ratcheting, defined as the ratchet-induced collapse in this study, is one of the failure modes of piping components under seismic loading. This failure mode was first confirmed in the Pipe-fitting dynamic reliability program (PFDRP) conducted by EPRI in the 1980s. However, the mechanism and occurrence condition of this failure remained unclear for decades because there were no methods to express the continuous transition of failure modes under seismic loading, as ratcheting turned into a plastic collapse behavior in the experiment. In this study, the mechanism of the ratchet-induced collapse is clarified using numerical analyses and experimental tests. The X-Y trajectory representing the transition of the stress levels of deadweight and seismic loading is introduced to express the significant effect of ratcheting. The seismic failure mode map, which has a similar classification of stresses with Bree’s diagram, is also extended to represent the occurrence condition of plastic collapse. The prediction method of the ratchet-induced collapse is proposed by combining the X-Y trajectory and the extended seismic failure mode map.
{"title":"Prediction Concept of Ratchet-Induced Collapse Under Deadweight and Seismic Loading","authors":"Satoru Kai, M. Ichimiya, N. Kasahara","doi":"10.1115/pvp2022-84508","DOIUrl":"https://doi.org/10.1115/pvp2022-84508","url":null,"abstract":"\u0000 The failure mode estimation of essential components in nuclear facilities under beyond design-basis events (BDBEs) is necessary to mitigate the consequences during severe accident conditions. The plastic collapse induced by ratcheting, defined as the ratchet-induced collapse in this study, is one of the failure modes of piping components under seismic loading. This failure mode was first confirmed in the Pipe-fitting dynamic reliability program (PFDRP) conducted by EPRI in the 1980s. However, the mechanism and occurrence condition of this failure remained unclear for decades because there were no methods to express the continuous transition of failure modes under seismic loading, as ratcheting turned into a plastic collapse behavior in the experiment. In this study, the mechanism of the ratchet-induced collapse is clarified using numerical analyses and experimental tests. The X-Y trajectory representing the transition of the stress levels of deadweight and seismic loading is introduced to express the significant effect of ratcheting. The seismic failure mode map, which has a similar classification of stresses with Bree’s diagram, is also extended to represent the occurrence condition of plastic collapse. The prediction method of the ratchet-induced collapse is proposed by combining the X-Y trajectory and the extended seismic failure mode map.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80440507","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}
Bolted flange connections are widely used in the transportation, power generation, and chemical production industries. The goal of these connections is to contain the media within the bolted flange connections with minimal leaks. While there is increased focus in the industry on general flange assembly best practices, there is little to no focus on flange assembly best practices involving extension tools. In the circumstances, extension tools could be required to reach the fasteners to apply a predetermined torque. Yet, how do we know the torque set on the torque wrench is the same torque transmitted through the torque wrench and the extension to the fastener? Does the length of the extension and torque wrench matter, or does the orientation or angle of the extension in relation to the torque wrench affect the resultant torque? This paper will explore the variables which affect the applied torque when using an extension tool and detail the best practices to utilize when using this system to tighten bolted flange connections. With the data collected for this testing, end-users will gain a better understanding of the variables affecting the applied torque when using an extension and methods of ensuring the proper torque is applied to each fastener.
{"title":"Best Practices for Tightening Bolted Flange Connections Utilizing a Torque Wrench With an Extension","authors":"S. Benet, Ross Dupre, Jeffery Wilson","doi":"10.1115/pvp2022-83963","DOIUrl":"https://doi.org/10.1115/pvp2022-83963","url":null,"abstract":"\u0000 Bolted flange connections are widely used in the transportation, power generation, and chemical production industries. The goal of these connections is to contain the media within the bolted flange connections with minimal leaks. While there is increased focus in the industry on general flange assembly best practices, there is little to no focus on flange assembly best practices involving extension tools. In the circumstances, extension tools could be required to reach the fasteners to apply a predetermined torque. Yet, how do we know the torque set on the torque wrench is the same torque transmitted through the torque wrench and the extension to the fastener? Does the length of the extension and torque wrench matter, or does the orientation or angle of the extension in relation to the torque wrench affect the resultant torque?\u0000 This paper will explore the variables which affect the applied torque when using an extension tool and detail the best practices to utilize when using this system to tighten bolted flange connections. With the data collected for this testing, end-users will gain a better understanding of the variables affecting the applied torque when using an extension and methods of ensuring the proper torque is applied to each fastener.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77687241","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 Fatigue lifetime assessment of pressurized components e.g. in nuclear power plants (NPPs) is an essential part of the aging management (AM) ensuring safe and reliable long term operation (LTO). The practically applied calculation procedures of different international codes and standards are widely affected by the basic principles formulated in the criteria document [1]. Those criteria are still fundamental for the fatigue assessment of pressure vessel and power plant components and there is good reason to target at improvements in the consideration of the major factors of influence on the fatigue lifetime while keeping the well-proven methodological framework. This paves the way to related future design code amendment proposals. In practice, there are often large discrepancies between calculated fatigue life and practical experience from power plant operation, where the operating experience reveals much higher fatigue lifetimes as their predictions based on laboratory tests and conservative consideration of major influencing factors (plastification by Ke-factors, Environmentally Assisted Fatigue (EAF) by FEN-factors) in the calculation approach. In the framework of a cooperative research program (see e.g. [2], [3] and [4]) including various subprojects Framatome GmbH, Erlangen, and the Materials Testing Institute MPA Stuttgart have been developing improvements to the fatigue lifetime assessment methods in the framework of the well established engineering approach [1]. These improvements are consolidated by the results of experiments on specimens of ferritic and austenitic stainless steels and austenitic stainless steel welds as well as component tests are performed under laboratory and operating conditions to improve fatigue assessment. The following aspects are going to be pointed out - Consideration of hold time and environmental (EAF) effects including the threshold and fatigue limit behavior - Relevance of multiaxial non-proportionality effects for typical power plant operational loading histories - Consideration of the cyclic elastic-plastic deformation behavior - Integration of the fatigue damage parameter approach into the calculation concept (particularly modified fatigue damage parameter of Haibach and Lehrke PHL,mod and fatigue damage parameter PJ) - Low-Cycle (LCF), High-Cycle (HCF) and Very High-Cycle (VHCF) fatigue behavior, interaction and related damage accumulation effects including the transient fatigue limit. The paper gives an overview of the state of the calculation concept.
{"title":"Recent Developments of Advanced Calculation Concepts for the Fatigue Assessment of Power Plant Components","authors":"T. Schopf, S. Weihe, J. Rudolph","doi":"10.1115/pvp2022-85543","DOIUrl":"https://doi.org/10.1115/pvp2022-85543","url":null,"abstract":"\u0000 The Fatigue lifetime assessment of pressurized components e.g. in nuclear power plants (NPPs) is an essential part of the aging management (AM) ensuring safe and reliable long term operation (LTO). The practically applied calculation procedures of different international codes and standards are widely affected by the basic principles formulated in the criteria document [1]. Those criteria are still fundamental for the fatigue assessment of pressure vessel and power plant components and there is good reason to target at improvements in the consideration of the major factors of influence on the fatigue lifetime while keeping the well-proven methodological framework. This paves the way to related future design code amendment proposals. In practice, there are often large discrepancies between calculated fatigue life and practical experience from power plant operation, where the operating experience reveals much higher fatigue lifetimes as their predictions based on laboratory tests and conservative consideration of major influencing factors (plastification by Ke-factors, Environmentally Assisted Fatigue (EAF) by FEN-factors) in the calculation approach. In the framework of a cooperative research program (see e.g. [2], [3] and [4]) including various subprojects Framatome GmbH, Erlangen, and the Materials Testing Institute MPA Stuttgart have been developing improvements to the fatigue lifetime assessment methods in the framework of the well established engineering approach [1]. These improvements are consolidated by the results of experiments on specimens of ferritic and austenitic stainless steels and austenitic stainless steel welds as well as component tests are performed under laboratory and operating conditions to improve fatigue assessment. The following aspects are going to be pointed out\u0000 - Consideration of hold time and environmental (EAF) effects including the threshold and fatigue limit behavior\u0000 - Relevance of multiaxial non-proportionality effects for typical power plant operational loading histories\u0000 - Consideration of the cyclic elastic-plastic deformation behavior\u0000 - Integration of the fatigue damage parameter approach into the calculation concept (particularly modified fatigue damage parameter of Haibach and Lehrke PHL,mod and fatigue damage parameter PJ)\u0000 - Low-Cycle (LCF), High-Cycle (HCF) and Very High-Cycle (VHCF) fatigue behavior, interaction and related damage accumulation effects including the transient fatigue limit.\u0000 The paper gives an overview of the state of the calculation concept.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77817286","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}
Soot deposit accumulation on heat transfer tubes and surfaces in recovery boilers reduces thermal performance, compromising thus the efficiency and life of the equipment. A soot blower is employed to remove these by-products to maintain boilers within design conditions. This specialized device has a seal between its tubes to maintain fluid pressure to clean the heating pipes and inside surface. Nevertheless, sealing can be a challenge due to its large displacement amplitude, the reciprocating movement, and the sudden change of temperature and pressure. Many different solutions are available in the market that offers viable sealing methods, but there is no test method to classify them. This work proposes a soot blower test protocol to evaluate the sealing solutions available. Comparative results for the different seal types are presented.
{"title":"Developing a Test Protocol to Determine Packing Performance in a Soot Blower","authors":"I. R. Henriques, Igor Meira, Carlos D. Girão","doi":"10.1115/pvp2022-84869","DOIUrl":"https://doi.org/10.1115/pvp2022-84869","url":null,"abstract":"\u0000 Soot deposit accumulation on heat transfer tubes and surfaces in recovery boilers reduces thermal performance, compromising thus the efficiency and life of the equipment. A soot blower is employed to remove these by-products to maintain boilers within design conditions. This specialized device has a seal between its tubes to maintain fluid pressure to clean the heating pipes and inside surface. Nevertheless, sealing can be a challenge due to its large displacement amplitude, the reciprocating movement, and the sudden change of temperature and pressure. Many different solutions are available in the market that offers viable sealing methods, but there is no test method to classify them. This work proposes a soot blower test protocol to evaluate the sealing solutions available. Comparative results for the different seal types are presented.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87240735","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}
Shutong Zhang, R. Giorjão, Jacque W. Berkson, J. Penso, Haixia Guo, Simon Yuen, L. Ely, A. Ramirez
Welding repair has been widely used to restore the structural integrity of coke drums compromised by cracks due to low-cycle fatigue failure among other damaging mechanisms. Nevertheless, due to the heterogeneous mechanical and metallurgical properties, repair welds are susceptible to re-cracking during subsequent operations. The API 1996 report has shown that 88% of outer-diameter (OD) repair welds have experienced re-cracking in coke drums. The re-cracking susceptibility downgrades the efficiency of welding repair to extend coke drum operation life and may increase the complexity of coke drum maintenance. Hence, addressing the low-cycle fatigue failure of weld becomes a critical issue to optimize welding repair for coke drum maintenance. Alloy 625 is a commonly used Ni-based filler metal to perform coke drum repairs due to its good thermal and metallurgical compatibility with the base metal. However, weld metal dilution close to the weld interface changes local microstructure and mechanical properties from the rest part of the weld. In this study, an external repair welds of 1.25Cr-0.5Mo steel under as-received (Normalized and Tempered) and service-aged conditions with Alloy 625 using HP-GTAW process are evaluated based on low-cycle fatigue tests and failure analysis. Weld transition samples are extracted to encompass the transition from weld metal to base metal at the gage section. Low-cycle fatigue tests are performed at 0.7%, 1.0%, 1.5% and 2.0% strain amplitudes. Interfacial cracks are observed at lower strain amplitudes (0.7% and 1.0%) and failures at higher strain amplitudes tend to occur at the base metal region. Metallurgical characterizations are performed to characterize the microstructure at weld interface and measure the mechanical properties through micro hardness. Interfacial cracks are examined using Scanning Electron Microscopy. This study helps clarify how microstructure and mechanical properties contribute to the interfacial cracking of the Ni-base alloy and steel dissimilar joint.
{"title":"Investigating Weld Interface Cracking of 1.25Cr-0.5Mo Steel External Weld Repair with Alloy 625 Filler Metal due to Low-cycle Fatigue Failure","authors":"Shutong Zhang, R. Giorjão, Jacque W. Berkson, J. Penso, Haixia Guo, Simon Yuen, L. Ely, A. Ramirez","doi":"10.1115/pvp2022-84764","DOIUrl":"https://doi.org/10.1115/pvp2022-84764","url":null,"abstract":"\u0000 Welding repair has been widely used to restore the structural integrity of coke drums compromised by cracks due to low-cycle fatigue failure among other damaging mechanisms. Nevertheless, due to the heterogeneous mechanical and metallurgical properties, repair welds are susceptible to re-cracking during subsequent operations. The API 1996 report has shown that 88% of outer-diameter (OD) repair welds have experienced re-cracking in coke drums. The re-cracking susceptibility downgrades the efficiency of welding repair to extend coke drum operation life and may increase the complexity of coke drum maintenance. Hence, addressing the low-cycle fatigue failure of weld becomes a critical issue to optimize welding repair for coke drum maintenance. Alloy 625 is a commonly used Ni-based filler metal to perform coke drum repairs due to its good thermal and metallurgical compatibility with the base metal. However, weld metal dilution close to the weld interface changes local microstructure and mechanical properties from the rest part of the weld. In this study, an external repair welds of 1.25Cr-0.5Mo steel under as-received (Normalized and Tempered) and service-aged conditions with Alloy 625 using HP-GTAW process are evaluated based on low-cycle fatigue tests and failure analysis. Weld transition samples are extracted to encompass the transition from weld metal to base metal at the gage section. Low-cycle fatigue tests are performed at 0.7%, 1.0%, 1.5% and 2.0% strain amplitudes. Interfacial cracks are observed at lower strain amplitudes (0.7% and 1.0%) and failures at higher strain amplitudes tend to occur at the base metal region. Metallurgical characterizations are performed to characterize the microstructure at weld interface and measure the mechanical properties through micro hardness. Interfacial cracks are examined using Scanning Electron Microscopy. This study helps clarify how microstructure and mechanical properties contribute to the interfacial cracking of the Ni-base alloy and steel dissimilar joint.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89209546","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}
High pressure threaded closures designed to ASME VIII Div.1 and Div. 2 are used extensively in heat exchangers in the hydroprocessing industry, where design conditions in excess of 100 bar and 450 °C may be required. When there is a requirement to open for inspection and maintenance, the breech-lock or screw-plug design offers a cost-effective alternative to TEMA channel closure types because it eliminates the large cover flange and bolting (often associated to welded diaphragms), allows for sealing adjustments without being dismantled and provides quicker opening and closing operations. For services designed to operate with a pressure differential between circuits that cannot be isolated (High-High type) an internal assembly must be designed such that the sealing of the tubesheet gasket is maintained under all possible operating conditions. The assembly must transfer the loads from the bolts to the tubesheet gasket but also remain elastic over a range of operating conditions. The past work on this assembly type is reviewed and root causes of exchanger leaks reported in the literature are discussed. A finite element analysis study showed that typical designs for the internal load-carrying components undergo plastic deformation due to thermal expansion under certain operating conditions, leading to a loss of gasket seal. While sealing may be temporarily restored by acting on external bolts, for example by hot torquing, subsequent thermal cycles can result in further deformation such that the assembly may require unplanned maintenance or repair. The results of the study were used to guide development of a new closure concept using a conical disc spring to ensure adequate gasket stress for sealing of the tubesheet while maintaining elastic behavior of components under load for all anticipated operating conditions, including upsets. Finite element models were used to compare the new approach to the existing practice and to design a demonstration unit, which has since been fabricated. The conical disk spring for the demonstration unit was tested, confirming the elastic behavior over the anticipated load range and enabling calibration of strain gauges. The complete prototype was tested with mechanical and thermal loads to validate analysis results and confirm ease of assembly and disassembly. The new closure design can reduce plant shutdown time by eliminating leaks and damage during operation of screw-plug exchangers.
设计符合ASME VIII Div.1和Div. 2的高压螺纹密封件广泛应用于加氢工业的热交换器中，其设计条件可能需要超过100 bar和450°C。当需要打开进行检查和维护时，后锁或螺塞设计是TEMA通道关闭类型的一种经济有效的替代方案，因为它消除了大型盖板法兰和螺栓(通常与焊接隔膜相关)，允许在不拆卸的情况下进行密封调整，并提供更快的打开和关闭操作。对于设计用于在不能隔离的电路之间的压差(高-高型)下运行的服务，必须设计一个内部组件，以便在所有可能的操作条件下保持管板垫圈的密封性。总成必须将载荷从螺栓转移到管板垫片上，同时还要在一系列操作条件下保持弹性。回顾了过去对这种组合类型的工作，并讨论了文献报道的交换器泄漏的根本原因。一项有限元分析研究表明，典型的内部承载部件设计在一定的工作条件下，由于热膨胀而发生塑性变形，导致垫片密封失效。虽然可以通过作用于外部螺栓(例如热扭矩)暂时恢复密封，但后续的热循环可能会导致进一步的变形，从而需要对总成进行计划外的维护或维修。研究结果用于指导开发一种新的封闭概念，该概念使用锥形圆盘弹簧，以确保有足够的垫圈应力来密封管板，同时在所有预期的操作条件下保持组件的弹性行为，包括扰动。利用有限元模型将新方法与现有实践进行比较，并设计了一个示范装置，该装置已制作完成。对示范装置的锥形圆盘弹簧进行了测试，确认了其在预期载荷范围内的弹性行为，并能够对应变片进行校准。完整的原型进行了机械和热负荷测试，以验证分析结果，并确认装配和拆卸的便利性。新的关闭设计可以通过消除螺塞交换器运行过程中的泄漏和损坏来减少工厂停机时间。
{"title":"New Breech-Lock Exchanger Design to Ensure Gasket Sealing Under All Conditions","authors":"Roberto Groppi, R. Jibb, D. Creech","doi":"10.1115/pvp2022-84713","DOIUrl":"https://doi.org/10.1115/pvp2022-84713","url":null,"abstract":"\u0000 High pressure threaded closures designed to ASME VIII Div.1 and Div. 2 are used extensively in heat exchangers in the hydroprocessing industry, where design conditions in excess of 100 bar and 450 °C may be required. When there is a requirement to open for inspection and maintenance, the breech-lock or screw-plug design offers a cost-effective alternative to TEMA channel closure types because it eliminates the large cover flange and bolting (often associated to welded diaphragms), allows for sealing adjustments without being dismantled and provides quicker opening and closing operations. For services designed to operate with a pressure differential between circuits that cannot be isolated (High-High type) an internal assembly must be designed such that the sealing of the tubesheet gasket is maintained under all possible operating conditions. The assembly must transfer the loads from the bolts to the tubesheet gasket but also remain elastic over a range of operating conditions.\u0000 The past work on this assembly type is reviewed and root causes of exchanger leaks reported in the literature are discussed. A finite element analysis study showed that typical designs for the internal load-carrying components undergo plastic deformation due to thermal expansion under certain operating conditions, leading to a loss of gasket seal. While sealing may be temporarily restored by acting on external bolts, for example by hot torquing, subsequent thermal cycles can result in further deformation such that the assembly may require unplanned maintenance or repair.\u0000 The results of the study were used to guide development of a new closure concept using a conical disc spring to ensure adequate gasket stress for sealing of the tubesheet while maintaining elastic behavior of components under load for all anticipated operating conditions, including upsets. Finite element models were used to compare the new approach to the existing practice and to design a demonstration unit, which has since been fabricated. The conical disk spring for the demonstration unit was tested, confirming the elastic behavior over the anticipated load range and enabling calibration of strain gauges. The complete prototype was tested with mechanical and thermal loads to validate analysis results and confirm ease of assembly and disassembly. The new closure design can reduce plant shutdown time by eliminating leaks and damage during operation of screw-plug exchangers.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80650383","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 steel belt staggered multi-layer cylindrical shell is the preferred structure for high-pressure hydrogen storage vessel in refueling stations. However, it could be threatened by external blast loads from accidental hydrogen leaks and explosions. In this paper, detailed numerical model is established to analyze the elastoplastic response of such multi-layer cylindrical shell subjected to external blast loads of different TNT equivalency weights. The thermo-viscoplastic constitutive model and fluid-structure coupling approach are incorporated in the modeling. The radial displacement/vibration histories and the effective strain responses of different layers were analyzed to demonstrate the potential deformation of the shell structure. Also, the maximum strain at different locations of the shell structure are discussed. The results will be helpful to evaluate the integrity of such multi-layer cylindrical structure that undertakes the risk of external hydrogen explosion.
{"title":"On the Elastoplastic Dynamic Response of Steel Belt Staggered Multi-Layer Cylindrical Shell Subjected to External Blast Loading","authors":"Yuanqi Liu, Yang Du, Zhao Zhang, F. Zhou","doi":"10.1115/pvp2022-84467","DOIUrl":"https://doi.org/10.1115/pvp2022-84467","url":null,"abstract":"\u0000 The steel belt staggered multi-layer cylindrical shell is the preferred structure for high-pressure hydrogen storage vessel in refueling stations. However, it could be threatened by external blast loads from accidental hydrogen leaks and explosions. In this paper, detailed numerical model is established to analyze the elastoplastic response of such multi-layer cylindrical shell subjected to external blast loads of different TNT equivalency weights. The thermo-viscoplastic constitutive model and fluid-structure coupling approach are incorporated in the modeling. The radial displacement/vibration histories and the effective strain responses of different layers were analyzed to demonstrate the potential deformation of the shell structure. Also, the maximum strain at different locations of the shell structure are discussed. The results will be helpful to evaluate the integrity of such multi-layer cylindrical structure that undertakes the risk of external hydrogen explosion.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81004366","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}
This paper studies the influence of disordered parameters on vibration transmission characteristic of pipeline structure with periodic support. Transverse Band Gap structures (BGs) for perfect period and frequency response function (FRF) for finite periods are investigated and fit well with each other. By introducing a certain degree of uncertainty level, interval method is used to convert uncertain parameter problem into two deterministic models. FRF for near-periodic structure with single disorder and BGs for quasi-periodic structure with multiple disorders are investigated concerning support stiffness and periodic length. The existence of disorders in periodic structure would always reduce the attenuation intensity and interval, and some disturbance would even generate new intermediate attenuation zones. Elastic wave propagation with periodic support is much more sensitive to periodic length rather than support stiffness, as the sensitivity is closely related with attenuation mechanism. Therefore, such defects should be carefully avoided in design and manufacturing this kind of periodic pipeline structures. The work in this paper enriches the stability analysis of the pipeline structure with periodic support, and provides reference for the research of noise and vibration reduction of pipeline system in practical engineering.
{"title":"Disorders in Periodic Support for Pipeline Conveying Fluid","authors":"Qingna Zeng, Donghui Wang, F. Zang, Yixion Zhang","doi":"10.1115/pvp2022-83606","DOIUrl":"https://doi.org/10.1115/pvp2022-83606","url":null,"abstract":"\u0000 This paper studies the influence of disordered parameters on vibration transmission characteristic of pipeline structure with periodic support. Transverse Band Gap structures (BGs) for perfect period and frequency response function (FRF) for finite periods are investigated and fit well with each other. By introducing a certain degree of uncertainty level, interval method is used to convert uncertain parameter problem into two deterministic models. FRF for near-periodic structure with single disorder and BGs for quasi-periodic structure with multiple disorders are investigated concerning support stiffness and periodic length. The existence of disorders in periodic structure would always reduce the attenuation intensity and interval, and some disturbance would even generate new intermediate attenuation zones. Elastic wave propagation with periodic support is much more sensitive to periodic length rather than support stiffness, as the sensitivity is closely related with attenuation mechanism. Therefore, such defects should be carefully avoided in design and manufacturing this kind of periodic pipeline structures. The work in this paper enriches the stability analysis of the pipeline structure with periodic support, and provides reference for the research of noise and vibration reduction of pipeline system in practical engineering.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81301381","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}
Uncontrolled manual operation of high energy vent lines could cause immediate fatigue failure at branch connections. Past failures have been attributed to high kinetic energy created due to choked flow at unprotected small-bore branch connections. In this paper, a risk-assessment method has been developed for choked flow in high energy systems. Computational Fluid Dynamics (CFD) tools were used to simulate formation and propagation of shock wave. A state-of-art method Fluid Structure Interaction (FSI) was used to investigate the dynamic pressure fluctuation in the piping system. Finite Element Analysis (FEA) was used to evaluate stresses and vibration responses at the toe of welds. This study found the fatigue risk of choked flow is caused by high-frequency shell-mode vibration. However, unlike the other high-frequency shell-mode vibration phenomenon (the acoustic-induced-vibration) which propagates in the piping system, the risks of choked flow are found to be only in the immediate vicinity of the choking point and decays exponentially with distance. A vibration velocity index defined in recent publications is used and modified to predict the vibration stress in various pipe sizes and branch fittings. Mitigation options are also discussed in this paper.
{"title":"Evaluating and Mitigating Fatigue Risk of Choked Flow","authors":"Yuqing Liu, P. Diwakar, Ismat El Jaouhari, D. Lin","doi":"10.1115/pvp2022-84074","DOIUrl":"https://doi.org/10.1115/pvp2022-84074","url":null,"abstract":"\u0000 Uncontrolled manual operation of high energy vent lines could cause immediate fatigue failure at branch connections. Past failures have been attributed to high kinetic energy created due to choked flow at unprotected small-bore branch connections. In this paper, a risk-assessment method has been developed for choked flow in high energy systems. Computational Fluid Dynamics (CFD) tools were used to simulate formation and propagation of shock wave. A state-of-art method Fluid Structure Interaction (FSI) was used to investigate the dynamic pressure fluctuation in the piping system. Finite Element Analysis (FEA) was used to evaluate stresses and vibration responses at the toe of welds.\u0000 This study found the fatigue risk of choked flow is caused by high-frequency shell-mode vibration. However, unlike the other high-frequency shell-mode vibration phenomenon (the acoustic-induced-vibration) which propagates in the piping system, the risks of choked flow are found to be only in the immediate vicinity of the choking point and decays exponentially with distance. A vibration velocity index defined in recent publications is used and modified to predict the vibration stress in various pipe sizes and branch fittings. Mitigation options are also discussed in this paper.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84839109","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}
Ryan Holguin, D. Hill, Heidi Reichert, Kyle J. Deines, G. Bustos
This paper presents the results of ASME Boiler and Pressure Vessel Code (BPVC) Section VIII Division 2 analyses on a containment pressure vessel system designed to host small-scale shock physics experiments containing hazardous materials. These shock physics experiments are imaged using proton radiography at Los Alamos Neutron Science Center (LANSCE). The pressure vessel system examined is separated into two subsystems, the Outer Pressure Containment Vessel (OPCV) and the Beam Pipe and Auxiliary Hardware (BPAH). The OPCV mates with the BPAH to transport the proton beam and form the outer containment pressure boundary. An Inner Pressure Confinement Vessel (IPCV) is mounted inside the containment pressure boundary. The IPCV can be used to host a variety of physics experiments, which can include high explosive and hazardous materials. The IPCV is an impulsively loaded pressure vessel, while the OPCV and beam pipes are statically loaded. The OPCV and BPAH are designed to satisfy ASME BPVC Section VIII Division 2 Alternative Rules, Part 5 Design by Analysis Requirements for all load conditions expected during service. The BPAH is a series of stainless-steel tubes with low-profile flange assemblies, bellows, and aluminum windows to allow for proton imaging. The low-profile flanges are required for clearance of magnet bores located periodically along the length of the BPAH. The bellows are included along the beamline for ease of installation. The OPCV is a pressure vessel designed to interface with the BPAH, IPCV, and proton imaging alignment system. The OPCV and BPAH are both designed to support full vacuum loads. Major considerations for the BPAH are thermal elongation, collapse of bellows, and stresses due to clamp supports. Lifting loads and static equivalent loads transmitted from the IPCV are additional considerations for the OPCV. Under ASME BPVC Section VIII Division 2 Part 5.2.4, Elastic-Plastic Stress Analysis Method, Paragraph 5.2.4.3(a), Global Criteria, the requirements for analysis and acceptance are defined for the load cases described. A finite element analysis (FEA) model, performed in ANSYS 2020 R1, evaluates the design of the OPCV and BPAH under the aforementioned ASME guidance and criteria.
本文介绍了美国机械工程师协会(ASME)锅炉和压力容器规范(BPVC)第VIII节第2部分对用于承载含有有害物质的小型冲击物理实验的安全壳压力容器系统的分析结果。这些激波物理实验是在洛斯阿拉莫斯中子科学中心(LANSCE)使用质子射线摄影成像的。测试的压力容器系统分为两个子系统，外部压力容器(OPCV)和束管和辅助硬件(BPAH)。OPCV与BPAH配合传输质子束，形成外部安全壳压力边界。内压力约束容器(IPCV)安装在安全壳压力边界内。IPCV可用于举办各种物理实验，其中可以包括高爆炸性和危险物质。IPCV是一种脉冲载荷压力容器，而OPCV和束管是静载荷压力容器。OPCV和BPAH的设计满足ASME BPVC Section VIII Division 2 Alternative Rules, Part 5 Design by Analysis对服务期间所有预期负载条件的要求。BPAH由一系列不锈钢管组成，带有低轮廓的法兰组件、波纹管和铝窗，可以进行质子成像。沿BPAH长度周期性定位的磁铁孔的间隙需要低轮廓法兰。波纹管沿梁线安装，便于安装。OPCV是一种压力容器，设计用于与BPAH、IPCV和质子成像对准系统接口。OPCV和BPAH都设计为支持全真空负载。BPAH的主要考虑因素是热伸长率、波纹管的坍塌以及由于夹紧支撑而产生的应力。从IPCV传递的提升载荷和静态等效载荷是OPCV的额外考虑因素。根据ASME BPVC第VIII部分第2部分5.2.4，弹塑性应力分析方法，第5.2.4.3(a)段，全球标准，对所描述的载荷情况定义了分析和验收要求。在ANSYS 2020 R1中执行有限元分析(FEA)模型，在上述ASME指导和标准下评估OPCV和BPAH的设计。
{"title":"Finite Element Analysis of Outer Pressure Containment Vessel and Proton Beam Pipe for Proton Radiography Under Operational Loads","authors":"Ryan Holguin, D. Hill, Heidi Reichert, Kyle J. Deines, G. Bustos","doi":"10.1115/pvp2022-83987","DOIUrl":"https://doi.org/10.1115/pvp2022-83987","url":null,"abstract":"\u0000 This paper presents the results of ASME Boiler and Pressure Vessel Code (BPVC) Section VIII Division 2 analyses on a containment pressure vessel system designed to host small-scale shock physics experiments containing hazardous materials. These shock physics experiments are imaged using proton radiography at Los Alamos Neutron Science Center (LANSCE). The pressure vessel system examined is separated into two subsystems, the Outer Pressure Containment Vessel (OPCV) and the Beam Pipe and Auxiliary Hardware (BPAH). The OPCV mates with the BPAH to transport the proton beam and form the outer containment pressure boundary. An Inner Pressure Confinement Vessel (IPCV) is mounted inside the containment pressure boundary. The IPCV can be used to host a variety of physics experiments, which can include high explosive and hazardous materials. The IPCV is an impulsively loaded pressure vessel, while the OPCV and beam pipes are statically loaded. The OPCV and BPAH are designed to satisfy ASME BPVC Section VIII Division 2 Alternative Rules, Part 5 Design by Analysis Requirements for all load conditions expected during service. The BPAH is a series of stainless-steel tubes with low-profile flange assemblies, bellows, and aluminum windows to allow for proton imaging. The low-profile flanges are required for clearance of magnet bores located periodically along the length of the BPAH. The bellows are included along the beamline for ease of installation. The OPCV is a pressure vessel designed to interface with the BPAH, IPCV, and proton imaging alignment system. The OPCV and BPAH are both designed to support full vacuum loads. Major considerations for the BPAH are thermal elongation, collapse of bellows, and stresses due to clamp supports. Lifting loads and static equivalent loads transmitted from the IPCV are additional considerations for the OPCV. Under ASME BPVC Section VIII Division 2 Part 5.2.4, Elastic-Plastic Stress Analysis Method, Paragraph 5.2.4.3(a), Global Criteria, the requirements for analysis and acceptance are defined for the load cases described. A finite element analysis (FEA) model, performed in ANSYS 2020 R1, evaluates the design of the OPCV and BPAH under the aforementioned ASME guidance and criteria.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88232008","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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