A pressure equipment operator initiated a program to achieve compliance with a jurisdiction’s requirements for Overpressure Risk Assessment updates. The program was also initiated to provide clarifications and improvements in the pressure piping documentation where overpressure allowances were inherent in the design of heritage piping and equipment. Most of these heritage piping systems were designed between 1975 to 1995. During that period of time, it was a common industry practice to take advantage of the provision for variations per ASME B31.3 ¶302.2.4. As per this provision, it is acceptable for occasional, infrequent and short-in-duration upset events to exceed the design condition provided that all the requirements in ¶302.2.4 are met. The Overpressure Risk Assessment review of a large number of existing piping OPPSD systems recognized higher operating cases and higher overpressure upset cases than those in the original documentation. In most cases, the main reason for this inconsistency between the original and the recently calculated values is due to changes in API 520 / API 521 upset cases. Additionally, operating history, since facility start-up, provides data that demonstrates that upset events have occasionally exceeded the original values which are currently presented in the LDT. Updates to the original LDT are necessary to properly capture the experienced upset events, operating cases and, in some cases, design conditions. For heritage (pre-2013) pressure piping (PP) systems that require updates of the design pressure, the traditional margin provided between the new design pressure and the original leak test pressure as required by ASME B31.3 ¶345.4.2 will not be fully available to support the required rerate. The objective of this paper is to discuss whether another leak test, at a margin of 1.5 times new design pressure, would provide any additional value in terms of incremental safety. This is discussed in the context of pressure piping systems that have been in continuous successful service for between 25 and 43 years. The mechanical integrity of these systems is being ensured by monitoring and assessment activities that have been carried out within a comprehensive Pressure Equipment Integrity Program. The paper evaluates four different cases of the pressure piping systems that are in the scope of the program, discusses the purpose of leak testing in both construction and post-construction and lists potential risks associated with re-performing leak tests. The paper also provides recommendations for when a prior leak test is sufficient to demonstrate that a rerated piping system with a successful service history is suitable for the new service conditions.
一家压力设备运营商启动了一项计划，以满足管辖区对超压风险评估更新的要求。该计划还开始提供澄清和改进压力管道文件，其中超压允许在传统管道和设备的设计中是固有的。这些传统管道系统大多是在1975年至1995年之间设计的。在此期间，利用ASME B31.3¶302.2.4的变化条款是一种常见的行业惯例。根据此规定，只要满足¶302.2.4中的所有要求，就可以接受偶尔，不频繁和持续时间短的破坏事件超过设计条件。在对大量现有管道OPPSD系统进行的超压风险评估中，发现了比原始文件中更高的操作情况和超压破坏情况。在大多数情况下，原始值和最近计算值不一致的主要原因是由于API 520 / API 521混乱情况的变化。此外，自设施启动以来的运行历史提供的数据表明，扰动事件偶尔会超过LDT中当前显示的原始值。对原始LDT进行更新是必要的，以便正确地捕捉所经历的干扰事件、操作情况，以及在某些情况下的设计条件。对于需要更新设计压力的传统(pre-2013)压力管道(PP)系统，ASME B31.3¶345.4.2要求的新设计压力与原始泄漏测试压力之间提供的传统余量将无法完全用于支持所需的比率。本文的目的是讨论在新设计压力的1.5倍的范围内进行另一次泄漏测试是否会在增加安全性方面提供任何额外的价值。这是在压力管道系统的背景下讨论的，这些系统已经成功地连续使用了25到43年。这些系统的机械完整性是通过监测和评估活动来确保的，这些活动是在一个全面的压力设备完整性计划中进行的。本文对项目范围内的四种不同的压力管道系统进行了评估，讨论了施工和施工后进行泄漏测试的目的，并列出了与重新进行泄漏测试相关的潜在风险。该文件还提供了一些建议，说明什么时候预先的泄漏测试足以证明具有成功使用历史的参考管道系统适合新的使用条件。
{"title":"Leak Testing When Revising Operating, Upset, and Design Pressures in Pressure Piping","authors":"Trevor G. Seipp, Dina Kudzhak, Boyd Mckay","doi":"10.1115/pvp2022-85641","DOIUrl":"https://doi.org/10.1115/pvp2022-85641","url":null,"abstract":"\u0000 A pressure equipment operator initiated a program to achieve compliance with a jurisdiction’s requirements for Overpressure Risk Assessment updates. The program was also initiated to provide clarifications and improvements in the pressure piping documentation where overpressure allowances were inherent in the design of heritage piping and equipment. Most of these heritage piping systems were designed between 1975 to 1995.\u0000 During that period of time, it was a common industry practice to take advantage of the provision for variations per ASME B31.3 ¶302.2.4. As per this provision, it is acceptable for occasional, infrequent and short-in-duration upset events to exceed the design condition provided that all the requirements in ¶302.2.4 are met.\u0000 The Overpressure Risk Assessment review of a large number of existing piping OPPSD systems recognized higher operating cases and higher overpressure upset cases than those in the original documentation. In most cases, the main reason for this inconsistency between the original and the recently calculated values is due to changes in API 520 / API 521 upset cases. Additionally, operating history, since facility start-up, provides data that demonstrates that upset events have occasionally exceeded the original values which are currently presented in the LDT. Updates to the original LDT are necessary to properly capture the experienced upset events, operating cases and, in some cases, design conditions. For heritage (pre-2013) pressure piping (PP) systems that require updates of the design pressure, the traditional margin provided between the new design pressure and the original leak test pressure as required by ASME B31.3 ¶345.4.2 will not be fully available to support the required rerate.\u0000 The objective of this paper is to discuss whether another leak test, at a margin of 1.5 times new design pressure, would provide any additional value in terms of incremental safety. This is discussed in the context of pressure piping systems that have been in continuous successful service for between 25 and 43 years. The mechanical integrity of these systems is being ensured by monitoring and assessment activities that have been carried out within a comprehensive Pressure Equipment Integrity Program. The paper evaluates four different cases of the pressure piping systems that are in the scope of the program, discusses the purpose of leak testing in both construction and post-construction and lists potential risks associated with re-performing leak tests. The paper also provides recommendations for when a prior leak test is sufficient to demonstrate that a rerated piping system with a successful service history is suitable for the new service conditions.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84085964","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}
Plant owners are responsible for specifying piping fluid service categories and determining the applicability of ASME B31.3 Chapter IX for high-pressure piping. However, the code only defines the design for high-pressure fluid service piping, and many designers and engineers are not fully aware of the best design practices for low-stress and high-cycle applications. Using innovative industry approaches and harmonic response analysis, dynamic stress levels of piping are calculated, and finite element analysis (FEA) used to calculate stress from the cycle range. This includes piping system design pressure at 10,200 psig with expectations of more than 1,000,000 stress cycles in a single day. A thermal flexibility analysis of the piping system along with a fatigue analysis for the entire piping components within the system is performed in accordance with ASME BPV code Section VIII Division 3. The fatigue stress ranges of a properly designed vibrating piping system are typically well below the ASME BPV code limit. High-pressure, unlisted piping fitting components such as reducers, tees, elbows and flanges, are also analyzed using the FEA and ASME BPV code design procedures. This paper discusses the design process and deviations from the base code for piping design requirements as well as special techniques to consider for high-pressure and high-cycle piping.
{"title":"Performing Under Pressure – Design Guidance for High-Pressure, High Cycle Piping System","authors":"Jae-Qu Chae","doi":"10.1115/pvp2022-84824","DOIUrl":"https://doi.org/10.1115/pvp2022-84824","url":null,"abstract":"\u0000 Plant owners are responsible for specifying piping fluid service categories and determining the applicability of ASME B31.3 Chapter IX for high-pressure piping. However, the code only defines the design for high-pressure fluid service piping, and many designers and engineers are not fully aware of the best design practices for low-stress and high-cycle applications.\u0000 Using innovative industry approaches and harmonic response analysis, dynamic stress levels of piping are calculated, and finite element analysis (FEA) used to calculate stress from the cycle range. This includes piping system design pressure at 10,200 psig with expectations of more than 1,000,000 stress cycles in a single day.\u0000 A thermal flexibility analysis of the piping system along with a fatigue analysis for the entire piping components within the system is performed in accordance with ASME BPV code Section VIII Division 3. The fatigue stress ranges of a properly designed vibrating piping system are typically well below the ASME BPV code limit.\u0000 High-pressure, unlisted piping fitting components such as reducers, tees, elbows and flanges, are also analyzed using the FEA and ASME BPV code design procedures.\u0000 This paper discusses the design process and deviations from the base code for piping design requirements as well as special techniques to consider for high-pressure and high-cycle piping.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"66 12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91019826","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}
Polytetrafluoroethylene (PTFE) is an excellent gasket material, chemically, but it has relatively poor mechanical performance. As a result, much effort has gone into improving the mechanical performance of PTFE-based gasket materials. Methods to improve mechanical performance include the addition of fillers (glass fibers, glass microspheres, silica, barium sulfate, carbon, etc.) and the manipulation of the microstructure (micro-cellular, expanded, restructured, etc.). These various forms of PTFE materials can have widely varying mechanical performance. PTFE materials that are chemically the same will have significantly different mechanical performance if the manufacturing process and microstructure are different. An example is the performance of amorphous, virgin PTFE sheet compared to fibrillated, expanded PTFE (ePTFE) sheet. The thickness of a gasket material is another structural difference that results in different mechanical performance. This paper explores the difference in the mechanical performance of two common filled PTFE (fPTFE) materials that end-users often consider functionally the same at several industrially important thicknesses. The gasket materials are both barium sulfate-filled, restructured PTFE sheet materials. The mechanical performance of each material is compared for three thicknesses using the Hot Blowout Thermal Cycling test (HOBTC, ASTM WK61856 Rev 10-9-2020). [1] The thicknesses are 0.79 mm (0.031 inch), 1.60 mm (0.063 inch), and 3.18 mm (0.125 inch). The authors selected these thicknesses for performance review because of their usage in the industry. The thinnest, 0.79 mm (0.031 inch), is commonly used for instrument service. Very little performance data is publicly available on this thickness. The medium thickness, 1.60 mm (0.063 inch), is most commonly used in piping flanges. The thickest reviewed for this paper, 3.18 mm (0.125 inch), is commonly used for pressure vessels but also shows up in piping. Leakage testing according to the Room Temperature Tightness test (ROTT or ASTM F2836 Standard Practice for Gasket Constants for Bolted Joint Design) [2] was performed on the thinner 0.79 mm (0.031 inch) materials. HOBTC and ROTT testing was performed on an amtec TEMES fl.ai1 test fixture over the latter half of 2021 at the authors’ company. This data will demonstrate to the end-user how different the mechanical behavior can be of the same gasket material differing only in how thick it is.
{"title":"PTFE Gasket Material Performance Variation With Thickness","authors":"Anita R. Bausman, Jeffer J. Wilson","doi":"10.1115/pvp2022-84765","DOIUrl":"https://doi.org/10.1115/pvp2022-84765","url":null,"abstract":"\u0000 Polytetrafluoroethylene (PTFE) is an excellent gasket material, chemically, but it has relatively poor mechanical performance. As a result, much effort has gone into improving the mechanical performance of PTFE-based gasket materials. Methods to improve mechanical performance include the addition of fillers (glass fibers, glass microspheres, silica, barium sulfate, carbon, etc.) and the manipulation of the microstructure (micro-cellular, expanded, restructured, etc.). These various forms of PTFE materials can have widely varying mechanical performance. PTFE materials that are chemically the same will have significantly different mechanical performance if the manufacturing process and microstructure are different. An example is the performance of amorphous, virgin PTFE sheet compared to fibrillated, expanded PTFE (ePTFE) sheet. The thickness of a gasket material is another structural difference that results in different mechanical performance.\u0000 This paper explores the difference in the mechanical performance of two common filled PTFE (fPTFE) materials that end-users often consider functionally the same at several industrially important thicknesses. The gasket materials are both barium sulfate-filled, restructured PTFE sheet materials. The mechanical performance of each material is compared for three thicknesses using the Hot Blowout Thermal Cycling test (HOBTC, ASTM WK61856 Rev 10-9-2020). [1] The thicknesses are 0.79 mm (0.031 inch), 1.60 mm (0.063 inch), and 3.18 mm (0.125 inch). The authors selected these thicknesses for performance review because of their usage in the industry. The thinnest, 0.79 mm (0.031 inch), is commonly used for instrument service. Very little performance data is publicly available on this thickness. The medium thickness, 1.60 mm (0.063 inch), is most commonly used in piping flanges. The thickest reviewed for this paper, 3.18 mm (0.125 inch), is commonly used for pressure vessels but also shows up in piping. Leakage testing according to the Room Temperature Tightness test (ROTT or ASTM F2836 Standard Practice for Gasket Constants for Bolted Joint Design) [2] was performed on the thinner 0.79 mm (0.031 inch) materials. HOBTC and ROTT testing was performed on an amtec TEMES fl.ai1 test fixture over the latter half of 2021 at the authors’ company. This data will demonstrate to the end-user how different the mechanical behavior can be of the same gasket material differing only in how thick it is.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84837497","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 blast wave propagates into the surrounding air when the high-pressure gas pipeline burst. Both temperature and pressure increase very rapidly. The generation of the blast wave and structural dynamic fracture are tightly coupled together during the burst of the high-pressure gas pipeline. However, fracture behavior and characteristics that influence blast waves’ intensity and spatial shape are rarely studied. This paper establishes a numerical model incorporating strain-based failure criteria for pipe material and fluid-structure coupling algorithm. The dynamic crack growth of the pipe and the outer blast wave propagation can be successfully captured in every timestep. The model is validated by comparing the simulated explosion pressure history and peak overpressure outside the pipeline with the experimental results. The blast wave intensity changes and the distribution of overpressure in the jet direction are clarified. Then some critical parameters of the resulting fracture and blast wave are examined, such as the pipe diameter and wall thickness. Specifically, the relationship between pipe fracture and the generated blast field is discussed, providing a deeper understanding of this highly transient and strong fluid-structure interaction problem. The results would benefit the prediction and accident investigation of high-pressure gas pipeline rupture.
{"title":"Numerical Analysis on the Blast Field From Gas Pipeline Burst Considering Fluid-Structure Interaction","authors":"Yi Ren, Yang Du, F. Zhou","doi":"10.1115/pvp2022-84465","DOIUrl":"https://doi.org/10.1115/pvp2022-84465","url":null,"abstract":"\u0000 The blast wave propagates into the surrounding air when the high-pressure gas pipeline burst. Both temperature and pressure increase very rapidly. The generation of the blast wave and structural dynamic fracture are tightly coupled together during the burst of the high-pressure gas pipeline. However, fracture behavior and characteristics that influence blast waves’ intensity and spatial shape are rarely studied. This paper establishes a numerical model incorporating strain-based failure criteria for pipe material and fluid-structure coupling algorithm. The dynamic crack growth of the pipe and the outer blast wave propagation can be successfully captured in every timestep. The model is validated by comparing the simulated explosion pressure history and peak overpressure outside the pipeline with the experimental results. The blast wave intensity changes and the distribution of overpressure in the jet direction are clarified. Then some critical parameters of the resulting fracture and blast wave are examined, such as the pipe diameter and wall thickness. Specifically, the relationship between pipe fracture and the generated blast field is discussed, providing a deeper understanding of this highly transient and strong fluid-structure interaction problem. The results would benefit the prediction and accident investigation of high-pressure gas pipeline rupture.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88641571","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}
E. Feulvarch, A. Wasylyk, Abdelhak Benrabia, Divjot Jolly, P. Duranton
In the field of numerical simulation, mesh-morphing is a technique that can be used to modify an existing Finite Element Mesh by the means of applying a specific distortion. Most of mesh-morphing methods simply change the positions of the nodes, hence the initial mesh connectivity, as well as the material properties are retained, and the boundary conditions, loadings, contact settings, etc. can be applied without any change in the input file. In this way, a simulation model can be quickly adapted with regards to any changes in the geometry or a new geometry can be created without using a CAD model. This article introduces the concept of mesh morphing using only standard Finite Element Analysis software features. The presented morphing method is used to modify a complicated mesh given a sample of displacements at known locations. Like standard morphing techniques based on the Radial Basis Functions, a weight function is calculated for each node by using steady state thermal calculation. Then, displacements at known locations are imposed to some nodes and a standard mechanical equation system is solved to calculate the displacements of all the nodes of the structure. The presented method was applied to solve some industrial applications for Class 1 Nuclear components which are showed here in order to illustrate the method.
{"title":"Mesh Morphing Based on Standard FEA Software Features and Application to Crack Propagation","authors":"E. Feulvarch, A. Wasylyk, Abdelhak Benrabia, Divjot Jolly, P. Duranton","doi":"10.1115/pvp2022-78445","DOIUrl":"https://doi.org/10.1115/pvp2022-78445","url":null,"abstract":"\u0000 In the field of numerical simulation, mesh-morphing is a technique that can be used to modify an existing Finite Element Mesh by the means of applying a specific distortion. Most of mesh-morphing methods simply change the positions of the nodes, hence the initial mesh connectivity, as well as the material properties are retained, and the boundary conditions, loadings, contact settings, etc. can be applied without any change in the input file. In this way, a simulation model can be quickly adapted with regards to any changes in the geometry or a new geometry can be created without using a CAD model.\u0000 This article introduces the concept of mesh morphing using only standard Finite Element Analysis software features. The presented morphing method is used to modify a complicated mesh given a sample of displacements at known locations. Like standard morphing techniques based on the Radial Basis Functions, a weight function is calculated for each node by using steady state thermal calculation. Then, displacements at known locations are imposed to some nodes and a standard mechanical equation system is solved to calculate the displacements of all the nodes of the structure.\u0000 The presented method was applied to solve some industrial applications for Class 1 Nuclear components which are showed here in order to illustrate the method.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74984484","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}
As a lesson learned from the Fukushima nuclear power plant accident, the industry recognized the importance of mitigating accident consequences after Beyond Design Basis Events (BDBE). We propose the concept of applying fracture control to mitigate failure consequences of nuclear components under BDBE. This paper studies post-buckling behaviors of lower heads for fracture control of reactor vessels under BDBE. In the case of a reactor vessel that supports the weight of the vessel at the top, such as a fast reactor, if a loss of cooling accident occurs, the cylindrical body may rupture with large creep deformation due to extremely high temperature. In order to cope with this event, application of fracture control concept is proposed. As a concrete example of the countermeasure, it is considered that reactor vessel lower heads can contact the floor or other structures to relieve the load on the cylindrical body and avoid catastrophic failure of the cylindrical body. In order to achieve this, it is necessary that even if a lower head in contact with the floor or other structures buckles, the subsequent post-buckling behavior is stable to maintain the load carrying capacity, and there is a strength margin before the failure of the lower head. Buckling experiments and analyses were conducted on spherical shells with central cylindrical bodies and smooth spherical shells in contact with a rigid floor. The post-buckling behavior of all the above spherical shells was stable to maintain the load carrying capacity, and they did not fail immediately after buckling occurs. From above results that the load carrying capacity of the lower head is sufficiently maintained after buckling, it was shown that the rupture of the cylindrical body of reactor vessel can be controlled by redistributing the load on the cylindrical body, which is expected to rupture due to extremely high temperature at a loss of cooling function.re.
{"title":"Study on Post-Buckling Behaviors of Lower Heads for Fracture Control of Reactor Vessels Under BDBE","authors":"N. Kasahara, Masatoshi Murohara, Takuya Sato","doi":"10.1115/pvp2022-84449","DOIUrl":"https://doi.org/10.1115/pvp2022-84449","url":null,"abstract":"\u0000 As a lesson learned from the Fukushima nuclear power plant accident, the industry recognized the importance of mitigating accident consequences after Beyond Design Basis Events (BDBE). We propose the concept of applying fracture control to mitigate failure consequences of nuclear components under BDBE. This paper studies post-buckling behaviors of lower heads for fracture control of reactor vessels under BDBE.\u0000 In the case of a reactor vessel that supports the weight of the vessel at the top, such as a fast reactor, if a loss of cooling accident occurs, the cylindrical body may rupture with large creep deformation due to extremely high temperature. In order to cope with this event, application of fracture control concept is proposed. As a concrete example of the countermeasure, it is considered that reactor vessel lower heads can contact the floor or other structures to relieve the load on the cylindrical body and avoid catastrophic failure of the cylindrical body. In order to achieve this, it is necessary that even if a lower head in contact with the floor or other structures buckles, the subsequent post-buckling behavior is stable to maintain the load carrying capacity, and there is a strength margin before the failure of the lower head.\u0000 Buckling experiments and analyses were conducted on spherical shells with central cylindrical bodies and smooth spherical shells in contact with a rigid floor. The post-buckling behavior of all the above spherical shells was stable to maintain the load carrying capacity, and they did not fail immediately after buckling occurs.\u0000 From above results that the load carrying capacity of the lower head is sufficiently maintained after buckling, it was shown that the rupture of the cylindrical body of reactor vessel can be controlled by redistributing the load on the cylindrical body, which is expected to rupture due to extremely high temperature at a loss of cooling function.re.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73114495","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}
In this paper, a novel transport technique for pressure vessels based on electro-permanent magnet (EPM) technology is proposed. The magnetic force and the resulting transport gripping force (TGF) are applied by controllable permanent magnets rather than conventional electromagnet or permanent magnet technology, and the current is only required at the moment of loading or unloading the TGF. The EPM system is convenient in control, and low in energy consumption. The experimental device including magnetic chuck, web of foundation girder and other components is constructed based on the EPM characteristics and requirements of transported equipment. The EPM units are used to generate magnetic force to realize loading and unloading of TGF. The principles and advantages of EPM transport technique are first elaborated with theoretical derivation and magnetic field simulation. Then, a series of experiments such as electrical circuit, magnetic field and tensile test were performed for the EPM chuck and magnetic saddle. It is demonstrated that the TGF applied by the designed system is large enough for the transportation of the pressure vessel. Also, the energy saving is significant using the EPM transportation system.
{"title":"An Active Magnetic Saddle Based on Electro-Permanent Magnetic Adhesion Mechanism","authors":"Hongsheng Zhang, Yanbin Li, K. Guo, Jian Jiang","doi":"10.1115/pvp2022-84528","DOIUrl":"https://doi.org/10.1115/pvp2022-84528","url":null,"abstract":"\u0000 In this paper, a novel transport technique for pressure vessels based on electro-permanent magnet (EPM) technology is proposed. The magnetic force and the resulting transport gripping force (TGF) are applied by controllable permanent magnets rather than conventional electromagnet or permanent magnet technology, and the current is only required at the moment of loading or unloading the TGF. The EPM system is convenient in control, and low in energy consumption. The experimental device including magnetic chuck, web of foundation girder and other components is constructed based on the EPM characteristics and requirements of transported equipment. The EPM units are used to generate magnetic force to realize loading and unloading of TGF. The principles and advantages of EPM transport technique are first elaborated with theoretical derivation and magnetic field simulation. Then, a series of experiments such as electrical circuit, magnetic field and tensile test were performed for the EPM chuck and magnetic saddle. It is demonstrated that the TGF applied by the designed system is large enough for the transportation of the pressure vessel. Also, the energy saving is significant using the EPM transportation system.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77130827","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 API 579-1/ASME FFS-1 2016 Fitness-For-Service stress intensity factor solution for a plate with an embedded crack, infinite length, through-wall fourth order polynomial stress distribution (KPECL) was independently investigated in this work. Finite element models of cracked plates subjected to various applied stress fields were created and used to estimate stress intensity factors (K), which were then used to calibrate the respective influence coefficient values (Gi). The comparison of the newly calculated values to the existing values shows reasonable agreement for some values and a substantial difference for others. The new influence coefficients were also compared to values published by Le Delliou and Barthelet (2007) for the parameter combinations that exactly overlap with API 579-1/ASME FFS-1 2016. Excellent agreement was found with the new values presented herein. API 579-1/ASME FFS-1 2016 also recommends that the KPECL solution can be used for a cylinder with an embedded crack, longitudinal direction, infinite length, through-wall fourth order polynomial stress distribution (KCECLL) when the ratio of the internal radius (Ri) to wall thickness (t) is greater than or equal to five. As part of this work, influence coefficient values were also calculated for Ri/t = 5 and are included in this paper. A comparison of each KPECL value to its respective KCECLL value indicates that the recommendation is a reasonable approximation. The new influence coefficient values are recommended for fitness for service assessments that involve either the KPECL scenario or the KCECLL scenario where Ri/t ≥ 5.
{"title":"Evaluation of the API 579-1/ASME FFS-1 KPECL and KCECLL Stress Intensity Factors","authors":"S. Altstadt","doi":"10.1115/pvp2022-84922","DOIUrl":"https://doi.org/10.1115/pvp2022-84922","url":null,"abstract":"\u0000 The API 579-1/ASME FFS-1 2016 Fitness-For-Service stress intensity factor solution for a plate with an embedded crack, infinite length, through-wall fourth order polynomial stress distribution (KPECL) was independently investigated in this work. Finite element models of cracked plates subjected to various applied stress fields were created and used to estimate stress intensity factors (K), which were then used to calibrate the respective influence coefficient values (Gi). The comparison of the newly calculated values to the existing values shows reasonable agreement for some values and a substantial difference for others. The new influence coefficients were also compared to values published by Le Delliou and Barthelet (2007) for the parameter combinations that exactly overlap with API 579-1/ASME FFS-1 2016. Excellent agreement was found with the new values presented herein. API 579-1/ASME FFS-1 2016 also recommends that the KPECL solution can be used for a cylinder with an embedded crack, longitudinal direction, infinite length, through-wall fourth order polynomial stress distribution (KCECLL) when the ratio of the internal radius (Ri) to wall thickness (t) is greater than or equal to five. As part of this work, influence coefficient values were also calculated for Ri/t = 5 and are included in this paper. A comparison of each KPECL value to its respective KCECLL value indicates that the recommendation is a reasonable approximation. The new influence coefficient values are recommended for fitness for service assessments that involve either the KPECL scenario or the KCECLL scenario where Ri/t ≥ 5.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75875979","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}
Composite overwrapped pressure cylinders with plastic liner (type IV) have a broad application prospect in high-pressure gaseous hydrogen storage due to their excellent properties, such as lightweight, corrosion resistance, fatigue resistance and low cost. Heterogeneous materials sealing is an important issue during the connection structure design between the plastic liner and the metal valve, where a rubber O-ring was often set for the sealing of hydrogen with high pressure. In this work, a finite element model (FEM) of the bottle mouth structure of composite overwrapped pressure cylinder composed of a plastic liner and a metal boss was established using the ABAQUS software, and the influences of boss shape and thickness of liner on the deformation and contact stress of rubber O-ring were analyzed. As a result, the shape and sizes of the metal boss and the liner were optimized and the connection structure between the liner and metal boss was determined. Based on the optimization, the effects of compression ratio, hydrogen pressure, backup ring and the temperature variation during the filling of composite overwrapped pressure vessel on the sealing performance of rubber O-ring were determined. The results of this work can provide guidance for the tightness analysis and lightweight design of composite overwrapped pressure vessels with plastic liners.
{"title":"Optimization and Property Analysis of the Sealing Structure of Type IV Cylinder for High-Pressure Hydrogen Storage","authors":"Jiahui Tao, Z. Fan, Peng Xu, Lu Wang, Jilin Xue","doi":"10.1115/pvp2022-84673","DOIUrl":"https://doi.org/10.1115/pvp2022-84673","url":null,"abstract":"\u0000 Composite overwrapped pressure cylinders with plastic liner (type IV) have a broad application prospect in high-pressure gaseous hydrogen storage due to their excellent properties, such as lightweight, corrosion resistance, fatigue resistance and low cost. Heterogeneous materials sealing is an important issue during the connection structure design between the plastic liner and the metal valve, where a rubber O-ring was often set for the sealing of hydrogen with high pressure. In this work, a finite element model (FEM) of the bottle mouth structure of composite overwrapped pressure cylinder composed of a plastic liner and a metal boss was established using the ABAQUS software, and the influences of boss shape and thickness of liner on the deformation and contact stress of rubber O-ring were analyzed. As a result, the shape and sizes of the metal boss and the liner were optimized and the connection structure between the liner and metal boss was determined. Based on the optimization, the effects of compression ratio, hydrogen pressure, backup ring and the temperature variation during the filling of composite overwrapped pressure vessel on the sealing performance of rubber O-ring were determined. The results of this work can provide guidance for the tightness analysis and lightweight design of composite overwrapped pressure vessels with plastic liners.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75467655","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 integrity assessment of reactor pressure vessel (RPV) often considers only the crack initiation to evaluate the safety margin and excludes the crack propagation analysis. In this contribution, the combined eXtended Finite Element (XFEM) method with the Initiation-Growth-Arrest (IGA) algorithm, shortly written as XFEM-IGA, is applied to a thick-walled cylindrical specimen with a circumferential crack under Pressurized Thermal Shock (PTS). The results of the crack propagation analysis are compared with the experimental ones to validate the approach, which were taken from large-scale experiments on thick-walled cylinders under PTS performed in the FALSIRE project. In order to simulate the cylinder with the XFEM-IGA approach, a reduced three dimensional finite element (FE) model of a small sector (a slice of the cylinder) is used by applying cyclic symmetry boundary conditions. Thus, the model profits from the cyclic symmetry not only of the cylinder geometry but also the circumferential crack. The closed-form for the stress intensity factor for an internal circumferential crack in a thick-walled cylinder is combined with the IGA algorithm and is presented to verify the quality of the results. The results are shown in terms of the SIF evolution and crack depth during the PTS transient. The crack depth shows several initiation-arrest-reinitiation cycles and final arrest. However, some differences in the number of these cycles and final crack depth are observed between the simulation and the experimental results.
{"title":"Thick-Walled Cylindrical Specimens Under PTS Loading: Crack Propagation Analysis With XFEM-IGA","authors":"D. F. Mora Méndez, M. Niffenegger, G. Mao","doi":"10.1115/pvp2022-83771","DOIUrl":"https://doi.org/10.1115/pvp2022-83771","url":null,"abstract":"\u0000 The integrity assessment of reactor pressure vessel (RPV) often considers only the crack initiation to evaluate the safety margin and excludes the crack propagation analysis. In this contribution, the combined eXtended Finite Element (XFEM) method with the Initiation-Growth-Arrest (IGA) algorithm, shortly written as XFEM-IGA, is applied to a thick-walled cylindrical specimen with a circumferential crack under Pressurized Thermal Shock (PTS). The results of the crack propagation analysis are compared with the experimental ones to validate the approach, which were taken from large-scale experiments on thick-walled cylinders under PTS performed in the FALSIRE project. In order to simulate the cylinder with the XFEM-IGA approach, a reduced three dimensional finite element (FE) model of a small sector (a slice of the cylinder) is used by applying cyclic symmetry boundary conditions. Thus, the model profits from the cyclic symmetry not only of the cylinder geometry but also the circumferential crack. The closed-form for the stress intensity factor for an internal circumferential crack in a thick-walled cylinder is combined with the IGA algorithm and is presented to verify the quality of the results. The results are shown in terms of the SIF evolution and crack depth during the PTS transient. The crack depth shows several initiation-arrest-reinitiation cycles and final arrest. However, some differences in the number of these cycles and final crack depth are observed between the simulation and the experimental results.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80916580","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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