Xin Liu, Liangxin Sun, Yongsheng Xu, Haitao Wang, G. Deng
In this study, numerical simulation is used to analyze the influence of the mechanical properties matching degree of weld, HAZ and base metal on the maximum axial strain of high steel grade pipeline. Based on ASME VIII-2 local strain limit criterion and cumulative damage model, the fracture process of girth weld structure under axial displacement and internal pressure is simulated with XFEM. The material parameters of base metal and weld which are necessary for the simulation calculation are obtained by monotonic tensile test, and the material parameters of HAZ are assumed to be lower than those of the weld and base metal to a certain extent. The results show that for different matching degree combinations, the crack initiation location always appears in the HAZ with the lowest mechanical properties, and the axial strain of the pipeline decreases with the increase of the internal pressure. For the undermatched girth weld, the lower the mechanical properties of the weld is, the smaller the maximum axial strain of the girth weld pipe is. For overmatched girth weld, when the internal pressure is less than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is higher than that of 10% overmatched girth weld pipe. However, when the internal pressure is higher than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is smaller.
{"title":"Research on the Influence of Girth Weld Joint Matching Degree on the Safety Performance of High Steel Grade Pipeline Based on ASME Local Strain Limit Criterion","authors":"Xin Liu, Liangxin Sun, Yongsheng Xu, Haitao Wang, G. Deng","doi":"10.1115/pvp2022-84636","DOIUrl":"https://doi.org/10.1115/pvp2022-84636","url":null,"abstract":"\u0000 In this study, numerical simulation is used to analyze the influence of the mechanical properties matching degree of weld, HAZ and base metal on the maximum axial strain of high steel grade pipeline. Based on ASME VIII-2 local strain limit criterion and cumulative damage model, the fracture process of girth weld structure under axial displacement and internal pressure is simulated with XFEM. The material parameters of base metal and weld which are necessary for the simulation calculation are obtained by monotonic tensile test, and the material parameters of HAZ are assumed to be lower than those of the weld and base metal to a certain extent. The results show that for different matching degree combinations, the crack initiation location always appears in the HAZ with the lowest mechanical properties, and the axial strain of the pipeline decreases with the increase of the internal pressure. For the undermatched girth weld, the lower the mechanical properties of the weld is, the smaller the maximum axial strain of the girth weld pipe is. For overmatched girth weld, when the internal pressure is less than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is higher than that of 10% overmatched girth weld pipe. However, when the internal pressure is higher than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is smaller.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88372722","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}
L. Stumpfrock, U. Weber, S. Weihe, M. Seidenfuss, Linda Mally
Laminar and quasi-laminar orientations of hydrogen flakes with an inclination up to 16° to the pressure retaining surface were found in pressure vessels of Belgian nuclear power plants. Because of their orientation, these crack tips undergo predominantly mixed-mode loading conditions under internal pressure and the induced stress and strain fields of the single crack tips influence each other. In a former paper, the failure behavior under mixed-mode loading conditions was investigated at RT (Room Temperature) in the upper shelf and in the lower transition region of the steel 22NiMoCr3-7, respectively. In this paper, the failure behavior will be shown for many different levels of material toughness (beginning from upper shelf down to the lower shelf region) on experiments. Additionally numerical simulations are carried out with extended micromechanical based damage mechanics models. For the description of ductile failure mode the Rousselier model is used and the Beremin model to calculate the probability of cleavage fracture. To simulate the sensitivity for low stress triaxiality damage by shear loading, the damage mechanics model was enhanced with a term to account for damage evolution by shear. For numerical simulations in the transition region of brittle-to-ductile failure a coupled damage mechanics model (enhanced Rousselier & Beremin) will be used. In this paper, the current state of the ongoing research project is presented.
{"title":"Investigations on the Failure Behavior of Specimens Containing Crack Fields Made by Additive Manufacturing","authors":"L. Stumpfrock, U. Weber, S. Weihe, M. Seidenfuss, Linda Mally","doi":"10.1115/pvp2022-84666","DOIUrl":"https://doi.org/10.1115/pvp2022-84666","url":null,"abstract":"\u0000 Laminar and quasi-laminar orientations of hydrogen flakes with an inclination up to 16° to the pressure retaining surface were found in pressure vessels of Belgian nuclear power plants. Because of their orientation, these crack tips undergo predominantly mixed-mode loading conditions under internal pressure and the induced stress and strain fields of the single crack tips influence each other.\u0000 In a former paper, the failure behavior under mixed-mode loading conditions was investigated at RT (Room Temperature) in the upper shelf and in the lower transition region of the steel 22NiMoCr3-7, respectively. In this paper, the failure behavior will be shown for many different levels of material toughness (beginning from upper shelf down to the lower shelf region) on experiments.\u0000 Additionally numerical simulations are carried out with extended micromechanical based damage mechanics models. For the description of ductile failure mode the Rousselier model is used and the Beremin model to calculate the probability of cleavage fracture. To simulate the sensitivity for low stress triaxiality damage by shear loading, the damage mechanics model was enhanced with a term to account for damage evolution by shear. For numerical simulations in the transition region of brittle-to-ductile failure a coupled damage mechanics model (enhanced Rousselier & Beremin) will be used. In this paper, the current state of the ongoing research project is presented.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88489018","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}
Many bolting professionals in the heavy industrial industry rely on the belief that “Washers play an essential role in generating and sustaining integrity in bolted assemblies.” [1] It is believed that washers improve the reliability of bolted joints by providing a consistent K-Factor by introducing a flat even plane on which the nut can rotate. During practical training we noticed that using washers resulted in greater difference in bolt load between studs than experienced without washers. That experience led the authors to hypothesize that washers do not improve the accuracy and repeatability of bolted flange joints. This paper reports the findings of a study conducted to test this hypothesis. The study recorded the variance in measured K-Factor when tightening nuts against various flange surfaces with and without washers and determined that, when properly lubricated, the performance of studs against various flange surfaces did not vary greatly from the performance of studs against washers. Additionally, in some cases washers introduced a source of variance in bolt load. In addition to their perceived benefit in generating and maintaining tension in the bolted flange joint, washers are understood to provide benefits including preventing damage to the flange surface, preventing galling of the flange surface, and preventing nut embedment. This study focused on the use of washers in generating the expected bolt load and did not assess those additional benefits of washer usage.
{"title":"Washers: Are They as Good as We Think?","authors":"Scott R. Hamilton, Dan Meigs","doi":"10.1115/pvp2022-83610","DOIUrl":"https://doi.org/10.1115/pvp2022-83610","url":null,"abstract":"\u0000 Many bolting professionals in the heavy industrial industry rely on the belief that “Washers play an essential role in generating and sustaining integrity in bolted assemblies.” [1] It is believed that washers improve the reliability of bolted joints by providing a consistent K-Factor by introducing a flat even plane on which the nut can rotate.\u0000 During practical training we noticed that using washers resulted in greater difference in bolt load between studs than experienced without washers. That experience led the authors to hypothesize that washers do not improve the accuracy and repeatability of bolted flange joints. This paper reports the findings of a study conducted to test this hypothesis.\u0000 The study recorded the variance in measured K-Factor when tightening nuts against various flange surfaces with and without washers and determined that, when properly lubricated, the performance of studs against various flange surfaces did not vary greatly from the performance of studs against washers. Additionally, in some cases washers introduced a source of variance in bolt load.\u0000 In addition to their perceived benefit in generating and maintaining tension in the bolted flange joint, washers are understood to provide benefits including preventing damage to the flange surface, preventing galling of the flange surface, and preventing nut embedment. This study focused on the use of washers in generating the expected bolt load and did not assess those additional benefits of washer usage.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85522750","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}
H. Lejeune, Philippe Rohart, M. Triay, Aurélien Di Rienzo
AFCEN is the publisher of the French Nuclear code RCC-M® (Design and Construction Rules for Mechanical Components of PWR Nuclear Islands) [1]. It has launched an action for the revision of the Annex Z V and F 7000, respectively concerning the design and the installation of the bolted flange connections. It should be published as probationary phase rules (Section VI of RCC-M®), in the next version of the code, in 2022. The proposed modifications for F 7000 have already been described in [2], and this paper focuses on the proposed modification for the calculation method detailed in the Annex Z V. First, the general philosophy and structure of the Annex, including both Taylor-Forge based (Z V 2000) and NF EN 1591-1 [3] based (Z V 3000) calculation methods, is introduced. Then the major proposed improvements introduced in Z V 2000 (Taylor-Forge based), compared to current edition, are detailed. This includes the management of the metal-to-metal contact (MMC) in the connection (between flanges or between flanges and the gasket limiter ring) that can be required in both assembly and operation. Moreover, the use of specific gasket types involved in these connections (Expanded Graphite Ring or Metal Energized C-Ring...) is covered in this paper. Finally, a focus is also performed on other introductions, like the management of standard connections (including standard flanges, gasket, and bolts), the account for the tightening scatter, the effective gasket width determination in regard with the flange rigidity, and the internal force variation in the connections due to thermal expansion.
AFCEN是法国核规范RCC-M®(压水堆核岛机械部件设计和施工规则)[1]的出版商。对附件zv和f7000分别进行了关于螺栓法兰连接的设计和安装的修订。它应该作为试用阶段规则(RCC-M®第VI节)在2022年的下一个版本的代码中发布。对f7000的拟议修改已经在[2]中进行了描述，本文重点介绍了附件Z V中详细介绍的计算方法的拟议修改。首先，介绍了附件的一般原理和结构，包括基于Taylor-Forge (Z V 2000)和基于NF EN 1591-1 [3] (Z V 3000)的计算方法。然后详细介绍了zv2000(基于Taylor-Forge)中提出的与当前版本相比的主要改进。这包括在装配和操作中可能需要的连接(法兰之间或法兰与垫圈限位环之间)中的金属对金属接触(MMC)的管理。此外，本文还介绍了这些连接中涉及的特定垫圈类型(膨胀石墨环或金属通电c形环…)的使用。最后，还重点介绍了其他内容，如标准连接(包括标准法兰、垫片和螺栓)的管理，拧紧分散的考虑，与法兰刚度有关的有效垫片宽度的确定，以及由于热膨胀而导致的连接内力变化。
{"title":"Revision of the Annex Z V Concerning the Calculation of Bolted Joints in the French Nuclear Code RCC-M®","authors":"H. Lejeune, Philippe Rohart, M. Triay, Aurélien Di Rienzo","doi":"10.1115/pvp2022-81911","DOIUrl":"https://doi.org/10.1115/pvp2022-81911","url":null,"abstract":"\u0000 AFCEN is the publisher of the French Nuclear code RCC-M® (Design and Construction Rules for Mechanical Components of PWR Nuclear Islands) [1]. It has launched an action for the revision of the Annex Z V and F 7000, respectively concerning the design and the installation of the bolted flange connections. It should be published as probationary phase rules (Section VI of RCC-M®), in the next version of the code, in 2022. The proposed modifications for F 7000 have already been described in [2], and this paper focuses on the proposed modification for the calculation method detailed in the Annex Z V.\u0000 First, the general philosophy and structure of the Annex, including both Taylor-Forge based (Z V 2000) and NF EN 1591-1 [3] based (Z V 3000) calculation methods, is introduced. Then the major proposed improvements introduced in Z V 2000 (Taylor-Forge based), compared to current edition, are detailed. This includes the management of the metal-to-metal contact (MMC) in the connection (between flanges or between flanges and the gasket limiter ring) that can be required in both assembly and operation. Moreover, the use of specific gasket types involved in these connections (Expanded Graphite Ring or Metal Energized C-Ring...) is covered in this paper. Finally, a focus is also performed on other introductions, like the management of standard connections (including standard flanges, gasket, and bolts), the account for the tightening scatter, the effective gasket width determination in regard with the flange rigidity, and the internal force variation in the connections due to thermal expansion.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"196 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86097399","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}
Feng Xu, Yongsheng Xu, Jianfei Song, Hongchao Suo, Xin Liu
Aiming at the problem that there is no effective tool to quickly analyze the mechanical response of long-distance buried pipelines, this paper uses the APDL language of ANSYS to compile a rapid solution program for the mechanical response of buried pipelines based on the soil spring model. The program is used to establish the calculation model of 500 m long pipe, and analyze the mechanical response of the pipeline with and without medium and subsidence. The value are compared with those of ABAQUS based on PSI unit and solid contact model. The results show that the calculation value of these three methods are in good agreement. The program can realize rapid modeling and accurate analysis of long-distance buried pipelines, and has high engineering application value.
{"title":"Numerical Simulation Comparative Analysis of Pipe Soil Interaction in Buried Pipeline","authors":"Feng Xu, Yongsheng Xu, Jianfei Song, Hongchao Suo, Xin Liu","doi":"10.1115/pvp2022-84573","DOIUrl":"https://doi.org/10.1115/pvp2022-84573","url":null,"abstract":"\u0000 Aiming at the problem that there is no effective tool to quickly analyze the mechanical response of long-distance buried pipelines, this paper uses the APDL language of ANSYS to compile a rapid solution program for the mechanical response of buried pipelines based on the soil spring model. The program is used to establish the calculation model of 500 m long pipe, and analyze the mechanical response of the pipeline with and without medium and subsidence. The value are compared with those of ABAQUS based on PSI unit and solid contact model. The results show that the calculation value of these three methods are in good agreement. The program can realize rapid modeling and accurate analysis of long-distance buried pipelines, and has high engineering application value.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89073623","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 the published standards, selection criteria for bolt materials for high temperature and high pressure environments (exceeding 540°C (1000°F) and 300 lb) has not been specified. In addition, it seems that there are few studies that summarize how the initial bolt load and the flange nominal diameter affect the change over time of the bolt load under a high temperature environment. This paper proposed formulas to calculate the changes over time in bolt stress and gasket stress easily due to bolt creep by applying the mechanical relationship of bolted flange joint. The changes over time in the bolt stress and the gasket stress calculated by the proposed formulas were fairly good agreement with the FEM and the experiments. By utilizing proposed formulas, it is possible to predict when retightening should be carried out for bolted flange joints operated continuously for a long period of time. Furthermore, in the present paper, the effects of initial bolt load, internal pressure, bolt materials, and flange nominal diameters on the sealing performance under high temperature environments are clarified by utilizing proposed formulas and FEM. As a result, this paper shows that the increasing initial bolt load against bolt creep under a high temperature environment can not be expected to be effective, and that the size of internal pressure and flange nominal diameter has small effects on the change over time of bolt load.
{"title":"Estimation of Bolt Creep Characteristics and Sealing Performance of Flanged Joints","authors":"Hiroshi Yamanaka","doi":"10.1115/pvp2022-78366","DOIUrl":"https://doi.org/10.1115/pvp2022-78366","url":null,"abstract":"\u0000 In the published standards, selection criteria for bolt materials for high temperature and high pressure environments (exceeding 540°C (1000°F) and 300 lb) has not been specified. In addition, it seems that there are few studies that summarize how the initial bolt load and the flange nominal diameter affect the change over time of the bolt load under a high temperature environment. This paper proposed formulas to calculate the changes over time in bolt stress and gasket stress easily due to bolt creep by applying the mechanical relationship of bolted flange joint. The changes over time in the bolt stress and the gasket stress calculated by the proposed formulas were fairly good agreement with the FEM and the experiments. By utilizing proposed formulas, it is possible to predict when retightening should be carried out for bolted flange joints operated continuously for a long period of time. Furthermore, in the present paper, the effects of initial bolt load, internal pressure, bolt materials, and flange nominal diameters on the sealing performance under high temperature environments are clarified by utilizing proposed formulas and FEM. As a result, this paper shows that the increasing initial bolt load against bolt creep under a high temperature environment can not be expected to be effective, and that the size of internal pressure and flange nominal diameter has small effects on the change over time of bolt load.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89584554","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 paper discusses the development of sealing technology within the organization with particular emphasis on the gasket manufactured by profiled winding wire. This will be referred to as a PWG. The paper is a continuation of the paper presented in Paris PVP2013-97050 and follow up papers in PVP2014-28948 and in PVP2018-84067. It discusses further laboratory testing and briefly describes two related field service case studies. The paper details tests which include: oxidation testing of graphite, compression and recovery testing, chemical resistance testing of fillers in Sulphuric Acid service. The two related studies are based around the use in a Western Canadian refinery on a hot vapour exchanger and on a Fluidised Catalytic Cracker problematic flange.
{"title":"The Follow Up Development and on the Usage of the Profiled Wire Gasket","authors":"Erik Sullivan, A. Currie","doi":"10.1115/pvp2022-80855","DOIUrl":"https://doi.org/10.1115/pvp2022-80855","url":null,"abstract":"\u0000 The paper discusses the development of sealing technology within the organization with particular emphasis on the gasket manufactured by profiled winding wire. This will be referred to as a PWG.\u0000 The paper is a continuation of the paper presented in Paris PVP2013-97050 and follow up papers in PVP2014-28948 and in PVP2018-84067. It discusses further laboratory testing and briefly describes two related field service case studies.\u0000 The paper details tests which include: oxidation testing of graphite, compression and recovery testing, chemical resistance testing of fillers in Sulphuric Acid service. The two related studies are based around the use in a Western Canadian refinery on a hot vapour exchanger and on a Fluidised Catalytic Cracker problematic flange.","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":"90230299","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}
Feng Xu, Yongsheng Xu, Jianfei Song, Cenfan Liu, Xin Liu
In recent years, there have been frequent leakage and explosion accidents caused by the cracking of the circumferential weld of buried pipelines, and soil subsidence is one of the main reasons for the accidents. This paper carries out a numerical simulation analysis based on the soil spring model of the buried pipeline, and studies the mechanical response laws such as axial stress and deformation of buried pipelines under different subsidence ranges. The results show that: With the increases of the subsidence range, the deformation of the pipeline first gradually increases, and then remains unchanged, the axial stress of the pipeline, first increases, then decreases slightly, and finally remains unchanged. With the increase of soil subsidence amount, the dangerous subsidence range of soil increases. When the subsidence amount reaches the yield displacement of the soil, with the increase of subsidence range, the maximum axial stress of the pipeline increases. The results have certain guiding significance for the design and maintenance of buried pipelines.
{"title":"Research on the Laws of Soil Subsidence Range on the Response of Buried Pipelines","authors":"Feng Xu, Yongsheng Xu, Jianfei Song, Cenfan Liu, Xin Liu","doi":"10.1115/pvp2022-84585","DOIUrl":"https://doi.org/10.1115/pvp2022-84585","url":null,"abstract":"\u0000 In recent years, there have been frequent leakage and explosion accidents caused by the cracking of the circumferential weld of buried pipelines, and soil subsidence is one of the main reasons for the accidents. This paper carries out a numerical simulation analysis based on the soil spring model of the buried pipeline, and studies the mechanical response laws such as axial stress and deformation of buried pipelines under different subsidence ranges. The results show that: With the increases of the subsidence range, the deformation of the pipeline first gradually increases, and then remains unchanged, the axial stress of the pipeline, first increases, then decreases slightly, and finally remains unchanged. With the increase of soil subsidence amount, the dangerous subsidence range of soil increases. When the subsidence amount reaches the yield displacement of the soil, with the increase of subsidence range, the maximum axial stress of the pipeline increases. The results have certain guiding significance for the design and maintenance of buried pipelines.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90547019","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}
Design of vessels for external pressure currently requires a chart-based solution or analytical approaches which are not necessarily intuitive. In this paper, we propose simple formulas for the external pressure evaluation of pipes and other cylindrical pressure vessels. We present a conceptual comparison between the elastic and elastic-plastic stability of structural columns and that of cylindrical vessels of long, intermediate, and short length. Their common features allow an accurate and straightforward approach for external pressure design. The approach is also extended to spherical caps, conical vessels, and formed heads. We compare the method presented to the current acceptance criteria from various design codes, including the ASME Boiler and Pressure Vessel Code Section VIII, Code Case 2286, and EN 13445-3, as well as codes for steel and aluminum structures. In further discussion, the simplified method is compared against the results of more than 500 experiments on the buckling of cylindrical and spherical vessels published over the past two centuries. This simple but accurate approximation is conceptually intuitive, analytically straightforward, and shows potential utility in pressure vessel design codes, as well as piping design codes such as B31 that currently reference ASME VIII for external pressure design.1
{"title":"Simplified Formulas for External Pressure Design","authors":"W. M. Kirkland, Christopher R. Bett","doi":"10.1115/pvp2022-78354","DOIUrl":"https://doi.org/10.1115/pvp2022-78354","url":null,"abstract":"\u0000 Design of vessels for external pressure currently requires a chart-based solution or analytical approaches which are not necessarily intuitive. In this paper, we propose simple formulas for the external pressure evaluation of pipes and other cylindrical pressure vessels. We present a conceptual comparison between the elastic and elastic-plastic stability of structural columns and that of cylindrical vessels of long, intermediate, and short length. Their common features allow an accurate and straightforward approach for external pressure design. The approach is also extended to spherical caps, conical vessels, and formed heads.\u0000 We compare the method presented to the current acceptance criteria from various design codes, including the ASME Boiler and Pressure Vessel Code Section VIII, Code Case 2286, and EN 13445-3, as well as codes for steel and aluminum structures. In further discussion, the simplified method is compared against the results of more than 500 experiments on the buckling of cylindrical and spherical vessels published over the past two centuries.\u0000 This simple but accurate approximation is conceptually intuitive, analytically straightforward, and shows potential utility in pressure vessel design codes, as well as piping design codes such as B31 that currently reference ASME VIII for external pressure design.1","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87349190","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 describes deterministic benchmark comparisons of 14 probabilistic fracture mechanics (PFM) codes. The benchmark problem focused on determining the leak-before-break behavior of a nickel-based alloy weld in a large-bore piping system of a pressurized-water reactor. The modeled degradation mechanism was primary water stress-corrosion cracking (PWSCC). The benchmark problem was deterministically analyzed with the PFM codes using their models for crack growth rates, stress-intensity factors, crack-opening displacements (CODs), crack transition from inside surface-breaking cracks to through-wall cracks, leak rates, and crack stability. Several output quantities of interest relevant to leak-before-break behavior were then compared. Other outputs as a function of the simulated component operating time were also compared, including the crack lengths and depths, stress-intensity factors, inside and outside surface CODs, and leak rates. An interpretation of these comparisons is provided in relation to the underlying models to better understand the effects of the different modeling approaches. Insights from this study will be used to inform probabilistic comparisons of the PFM codes, which will be presented in a subsequent paper.
{"title":"Probabilistic Fracture Mechanics Codes for Piping International Benchmark – Part 1: Deterministic Comparisons","authors":"Matthew Homiack","doi":"10.1115/pvp2022-84724","DOIUrl":"https://doi.org/10.1115/pvp2022-84724","url":null,"abstract":"\u0000 This paper describes deterministic benchmark comparisons of 14 probabilistic fracture mechanics (PFM) codes. The benchmark problem focused on determining the leak-before-break behavior of a nickel-based alloy weld in a large-bore piping system of a pressurized-water reactor. The modeled degradation mechanism was primary water stress-corrosion cracking (PWSCC). The benchmark problem was deterministically analyzed with the PFM codes using their models for crack growth rates, stress-intensity factors, crack-opening displacements (CODs), crack transition from inside surface-breaking cracks to through-wall cracks, leak rates, and crack stability. Several output quantities of interest relevant to leak-before-break behavior were then compared. Other outputs as a function of the simulated component operating time were also compared, including the crack lengths and depths, stress-intensity factors, inside and outside surface CODs, and leak rates. An interpretation of these comparisons is provided in relation to the underlying models to better understand the effects of the different modeling approaches. Insights from this study will be used to inform probabilistic comparisons of the PFM codes, which will be presented in a subsequent paper.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"146 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86024117","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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