Bolted flange joints using ring type joint (RTJ) gasket has been widely used in oil & gas industry especially for high pressure service less than and equals to 2500 psi or high temperature services. Recently performance of other types of gaskets, such as grooved metal and spiral wound gasket are increased and being reviewed, but RTJ is still a first option for many operators and designers. The flange and gasket design details are provided in ASME B16.5 and B16.47 and the details of the gasket and ring facing are provided in B16.20, however, field problem often occurs in construction site, especially the damage of the ring joint facing due to the overloading. Similar troubles have been reported in non-standard flange and when designing flange connection, additional attention should be paid in addition to the standard design procedure shown in ASME Sec.VIII div.1 Mandatory Appendix 2. To provide a guideline to design the flange joint and determine appropriate bolt load, detailed review and study was conducted. First, past troubles related to ring type joint are introduced, such as gasket coining into flange groove, and groove deformation of spacer component. Second, to clarify the root cause of such troubles, design of B16 flange, especially ring joint gasket size and facing geometry is reviewed and show gasket sizing and stress states varies with flange size and rating. A series of finite element analysis was performed, and analysis results are reviewed in terms of gasket stress, gasket contact pressure, groove stress and deformation. Finally, several recommendations on the determination of gasket size, flange groove dimension and initial tightening load are explained.
采用环型连接(RTJ)垫圈的螺栓法兰连接已广泛应用于石油和天然气行业，特别是小于等于2500psi的高压应用或高温应用。最近，其他类型的垫片(如凹槽金属垫片和螺旋缠绕垫片)的性能有所提高，但RTJ仍然是许多作业者和设计人员的首选。法兰和垫片的设计细节在ASME B16.5和B16.47中有规定，垫片和环面细节在B16.20中有规定，但施工现场经常出现现场问题，特别是环面因超载而损坏。类似的问题在非标准法兰中也有报道，在设计法兰连接时，除了ASME secv . viii div.1所示的标准设计程序外，还应额外注意。为指导翼缘节点的设计和确定合理的螺栓载荷，进行了详细的回顾和研究。首先，介绍了以往环型接头的问题，如垫片压入法兰槽、垫片部件槽变形等。其次，为了弄清这些问题的根本原因，回顾了B16法兰的设计，特别是环连接垫圈尺寸和端面几何形状，并显示了垫圈尺寸和应力状态随法兰尺寸和额定值的变化。进行了一系列的有限元分析，并从垫片应力、垫片接触压力、沟槽应力和变形等方面对分析结果进行了综述。最后对垫片尺寸、法兰槽尺寸和初始拧紧载荷的确定提出了几点建议。
{"title":"Design of B16 Standard and Non-Standard Ring Type Joint Flange and Gasket","authors":"S. Kataoka","doi":"10.1115/pvp2022-84883","DOIUrl":"https://doi.org/10.1115/pvp2022-84883","url":null,"abstract":"\u0000 Bolted flange joints using ring type joint (RTJ) gasket has been widely used in oil & gas industry especially for high pressure service less than and equals to 2500 psi or high temperature services. Recently performance of other types of gaskets, such as grooved metal and spiral wound gasket are increased and being reviewed, but RTJ is still a first option for many operators and designers. The flange and gasket design details are provided in ASME B16.5 and B16.47 and the details of the gasket and ring facing are provided in B16.20, however, field problem often occurs in construction site, especially the damage of the ring joint facing due to the overloading. Similar troubles have been reported in non-standard flange and when designing flange connection, additional attention should be paid in addition to the standard design procedure shown in ASME Sec.VIII div.1 Mandatory Appendix 2.\u0000 To provide a guideline to design the flange joint and determine appropriate bolt load, detailed review and study was conducted. First, past troubles related to ring type joint are introduced, such as gasket coining into flange groove, and groove deformation of spacer component. Second, to clarify the root cause of such troubles, design of B16 flange, especially ring joint gasket size and facing geometry is reviewed and show gasket sizing and stress states varies with flange size and rating. A series of finite element analysis was performed, and analysis results are reviewed in terms of gasket stress, gasket contact pressure, groove stress and deformation.\u0000 Finally, several recommendations on the determination of gasket size, flange groove dimension and initial tightening load are explained.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80302910","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}
Linbo Zhu, H. Pan, Yilong Yang, A. Bouzid, Jun Hong
Bolted flange joints are used to connect adjacent disks and drums in aero-engine rotors. The flange mating contact surfaces usually move relative to each other and deform when they are subjected to numerous combinations of loads during normal operation. Consequently, the local bending stiffness of the bolted flange joint is altered considerably affecting the overall rotor stiffness and therefore the rotor dynamics. This paper presents a study on the effect of the bending stiffness of bolted flange joints on the dynamic characteristics of an aero-engine rotor. A method to calculate the bending stiffness is proposed using an equivalent model based on an axial spring and bending beam stiffnesses. The relationship of the structure geometry, loading and assembly conditions of the bolted flange joints, and the bending stiffness loss are obtained. Furthermore, a dynamic model of an aero-engine high-pressure compressor rotor is developed using the transfer matrix method that incorporates the bending stiffness effect of the bolted flange joint. Based on this model, the influence of bending stiffness on the natural frequency and the steady-state response is discussed. The results show that the stiffness loss of bolted flange joint has a significant impact on the rotor dynamics. The structure geometry, loading, and assembly conditions can be used to control the dynamic response of aero-engine rotors.
{"title":"Effect of the Bending Stiffness of Bolted Flange Joints on the Dynamics of Aero-Engine Rotors","authors":"Linbo Zhu, H. Pan, Yilong Yang, A. Bouzid, Jun Hong","doi":"10.1115/pvp2022-84708","DOIUrl":"https://doi.org/10.1115/pvp2022-84708","url":null,"abstract":"\u0000 Bolted flange joints are used to connect adjacent disks and drums in aero-engine rotors. The flange mating contact surfaces usually move relative to each other and deform when they are subjected to numerous combinations of loads during normal operation. Consequently, the local bending stiffness of the bolted flange joint is altered considerably affecting the overall rotor stiffness and therefore the rotor dynamics.\u0000 This paper presents a study on the effect of the bending stiffness of bolted flange joints on the dynamic characteristics of an aero-engine rotor. A method to calculate the bending stiffness is proposed using an equivalent model based on an axial spring and bending beam stiffnesses. The relationship of the structure geometry, loading and assembly conditions of the bolted flange joints, and the bending stiffness loss are obtained. Furthermore, a dynamic model of an aero-engine high-pressure compressor rotor is developed using the transfer matrix method that incorporates the bending stiffness effect of the bolted flange joint. Based on this model, the influence of bending stiffness on the natural frequency and the steady-state response is discussed. The results show that the stiffness loss of bolted flange joint has a significant impact on the rotor dynamics. The structure geometry, loading, and assembly conditions can be used to control the dynamic response of aero-engine rotors.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"116 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80399058","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}
S. Asada, A. Hirano, Yun Wang, M. Itatani, M. Takanashi, Y. Nomura, Fumihiro Ochi, T. Ogawa
The subcommittees on Design Fatigue Curve (DFC) and Design Fatigue Curve 2 (DFC2) in Atomic Energy Research Committee of the Japan Welding Engineering Society (JWES) developed a new fatigue analysis method. A design fatigue curve by this method is established by applying factors on stress and cycles, which have been derived by statistical analysis, to the best-fit curve using tensile strength as a variable considering the mean stress correction called the Smith-Watson-Topper approach. For high cycle region, the variable amplitude effect of EN 13445 is employed. This fatigue analysis method was brought to the JSME Code Committee, and the JSME reviewed this method, and decided to incorporate it into the JSME Environmental Fatigue Evaluation Method with some modifications including the fatigue strength reduction factor for surface finish effect. This paper addresses surface finish effect on fatigue strength of carbon and low alloy steels. To perform further investigation for surface finish effect on fatigue strength of carbon and low alloy steels, the DFC3 Subcommittee was established with the support of a Japanese utility project. A series of fatigue tests for surface finish effect was performed for carbon and low alloy steels in the utility project, and the fatigue test data were evaluated by the DFC3 Subcommittee. In this paper, the series of fatigue tests are introduced and discussed. Finally, the validity for the fatigue strength reduction factor for surface finish effect developed by the JSME Committee has been confirmed based on the above fatigue tests.
{"title":"Investigation of Surface Finish Effect on Fatigue Strength of Carbon and Low Alloy Steels","authors":"S. Asada, A. Hirano, Yun Wang, M. Itatani, M. Takanashi, Y. Nomura, Fumihiro Ochi, T. Ogawa","doi":"10.1115/pvp2022-84695","DOIUrl":"https://doi.org/10.1115/pvp2022-84695","url":null,"abstract":"\u0000 The subcommittees on Design Fatigue Curve (DFC) and Design Fatigue Curve 2 (DFC2) in Atomic Energy Research Committee of the Japan Welding Engineering Society (JWES) developed a new fatigue analysis method. A design fatigue curve by this method is established by applying factors on stress and cycles, which have been derived by statistical analysis, to the best-fit curve using tensile strength as a variable considering the mean stress correction called the Smith-Watson-Topper approach. For high cycle region, the variable amplitude effect of EN 13445 is employed.\u0000 This fatigue analysis method was brought to the JSME Code Committee, and the JSME reviewed this method, and decided to incorporate it into the JSME Environmental Fatigue Evaluation Method with some modifications including the fatigue strength reduction factor for surface finish effect. This paper addresses surface finish effect on fatigue strength of carbon and low alloy steels.\u0000 To perform further investigation for surface finish effect on fatigue strength of carbon and low alloy steels, the DFC3 Subcommittee was established with the support of a Japanese utility project. A series of fatigue tests for surface finish effect was performed for carbon and low alloy steels in the utility project, and the fatigue test data were evaluated by the DFC3 Subcommittee. In this paper, the series of fatigue tests are introduced and discussed. Finally, the validity for the fatigue strength reduction factor for surface finish effect developed by the JSME Committee has been confirmed based on the above fatigue tests.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"507 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77835476","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}
Large volume multi-layered high pressure hydrogen storage vessel is one of the vital equipment in hydrogen refueling station. However, the possibility of leakage from container nozzles during service remains a safety concern. In this paper, a leakage model modified by the real gas equation of state and a three-dimensional (3D) computational fluid dynamics (CFD) model based on the real hydrogen refueling station layout are established to simulate the whole process of hydrogen diffusion and explosion after the large volume vessel leak. The influences of leakage direction, leakage height, hydrogen storage pressure and wind speed on the distribution of flammable hydrogen are studied, as well as the scope of overpressure harmful area is respectively predicted when the real hydrogen cloud is ignited at different times. Results indicate that the high-pressure hydrogen jet over 30MPa diffuses in a wide range near the surface under momentum control. And the smaller the leakage source height is, the more obvious the Coanda effect is. In addition, igniting after hydrogen leakage in a very short time (such as 0.5 s) will lead to higher maximum overpressure, and igniting after a long time will form a larger dangerous area. Compared with the seamless hydrogen storage cylinder group, the hydrogen explosion hazard of vertical large volume multi-layered hydrogen storage vessel is significantly alleviated after leakage. Also, setting a certain height of isolation walls outside the hydrogen storage area can effectively reduce the risk and consequences of accidents.
{"title":"Numerical Study of Hydrogen Leakage and Explosion in Hydrogen Refueling Station With Large Volume Hydrogen Storage Vessels","authors":"Chen Lu, Jieyi Hu, Sheng Ye, C. Gu, Z. Hua","doi":"10.1115/pvp2022-84464","DOIUrl":"https://doi.org/10.1115/pvp2022-84464","url":null,"abstract":"\u0000 Large volume multi-layered high pressure hydrogen storage vessel is one of the vital equipment in hydrogen refueling station. However, the possibility of leakage from container nozzles during service remains a safety concern. In this paper, a leakage model modified by the real gas equation of state and a three-dimensional (3D) computational fluid dynamics (CFD) model based on the real hydrogen refueling station layout are established to simulate the whole process of hydrogen diffusion and explosion after the large volume vessel leak. The influences of leakage direction, leakage height, hydrogen storage pressure and wind speed on the distribution of flammable hydrogen are studied, as well as the scope of overpressure harmful area is respectively predicted when the real hydrogen cloud is ignited at different times. Results indicate that the high-pressure hydrogen jet over 30MPa diffuses in a wide range near the surface under momentum control. And the smaller the leakage source height is, the more obvious the Coanda effect is. In addition, igniting after hydrogen leakage in a very short time (such as 0.5 s) will lead to higher maximum overpressure, and igniting after a long time will form a larger dangerous area. Compared with the seamless hydrogen storage cylinder group, the hydrogen explosion hazard of vertical large volume multi-layered hydrogen storage vessel is significantly alleviated after leakage. Also, setting a certain height of isolation walls outside the hydrogen storage area can effectively reduce the risk and consequences of accidents.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89005904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this paper is to investigate the parameters affecting the structural integrity for piping with dents anomalies. As per the requirements to part 12 of the API 579-1/ASME FFS-1, 2016 [1], level 1 and 2 fitness for service (FFS) assessment procedures can’t be used for dented pipe with diameter less than 6.25 inch. Such small size pipes can only be assessed using level 3 assessment procedure. The pipe was indented in the FEA model with a rigid indenter. The indented pipe was then evaluated under general collapse and local failure criteria under different loading combinations using the elastic plastic analysis approach. The pipe material is defined using a multi-linear isotropic hardening model as per Annex 3-D of ASME BPVC, sec. VIII, div. 2 [2]. The effect of nominal pipe size, pipe schedule, and dent’s radius of curvature and depth on the plastic strain, and strain ratio are studied. Following Taguchi design of experiments methodology [5], a partial factorial design was adopted to allow the investigation of multiple levels value for each parameter. This analysis uses a real-life dent profile which was measured using automatic ultrasound inspection (AUT) and fitted to a spherical profile. The significance of each parameter on the different measured responses is evaluated.
{"title":"Level 3 Fitness for Service Assessment of Dented Pipes With Diameter Less Than 6.25 Inch","authors":"K. Mostafa, A. Alian","doi":"10.1115/pvp2022-84935","DOIUrl":"https://doi.org/10.1115/pvp2022-84935","url":null,"abstract":"\u0000 The aim of this paper is to investigate the parameters affecting the structural integrity for piping with dents anomalies. As per the requirements to part 12 of the API 579-1/ASME FFS-1, 2016 [1], level 1 and 2 fitness for service (FFS) assessment procedures can’t be used for dented pipe with diameter less than 6.25 inch. Such small size pipes can only be assessed using level 3 assessment procedure. The pipe was indented in the FEA model with a rigid indenter. The indented pipe was then evaluated under general collapse and local failure criteria under different loading combinations using the elastic plastic analysis approach. The pipe material is defined using a multi-linear isotropic hardening model as per Annex 3-D of ASME BPVC, sec. VIII, div. 2 [2]. The effect of nominal pipe size, pipe schedule, and dent’s radius of curvature and depth on the plastic strain, and strain ratio are studied. Following Taguchi design of experiments methodology [5], a partial factorial design was adopted to allow the investigation of multiple levels value for each parameter. This analysis uses a real-life dent profile which was measured using automatic ultrasound inspection (AUT) and fitted to a spherical profile. The significance of each parameter on the different measured responses is evaluated.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"400 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79676243","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}
Intermittent pipe movement due to transient pressure events including vapor column collapse or water hammer events can impart large strains into the pipe, cause damage to the support structure, damage coatings, and cause damage or failure of the pipe. This paper will present a method that has been used with success for determining the pipe stresses and strains and possible cause associated with a transient pressure event based on coating damage evidence gathered from in-field assessments. After constructing a hydraulic model of the piping system, various transient events were modelled to obtain resulting pressure over the transient event’s period at key points along the piping system, such as valves and elbows. A second, more refined finite element model was created to incorporate the pressure values to determine the resulting displacements and stresses to relate to the in-field measurements of the region in question. By comparing the displacements in the model to the field evidence, the models were calibrated, and evaluation of the likely cause of coating damage found in the field was able to be performed. Moreover, the stresses in the pipe during the event are able to be assessed which allows for damage assessments to be conducted and allows for corrective actions to take place. Transient events assessed ranged from valve openings and closures, pump start up, and vapor column collapse.
{"title":"Diagnosis, Modelling and Assessment of Transient Pressure Events Based on Observed In-Field Evidence","authors":"T. J. Prewitt, M. Bednorz","doi":"10.1115/pvp2022-85658","DOIUrl":"https://doi.org/10.1115/pvp2022-85658","url":null,"abstract":"\u0000 Intermittent pipe movement due to transient pressure events including vapor column collapse or water hammer events can impart large strains into the pipe, cause damage to the support structure, damage coatings, and cause damage or failure of the pipe. This paper will present a method that has been used with success for determining the pipe stresses and strains and possible cause associated with a transient pressure event based on coating damage evidence gathered from in-field assessments. After constructing a hydraulic model of the piping system, various transient events were modelled to obtain resulting pressure over the transient event’s period at key points along the piping system, such as valves and elbows. A second, more refined finite element model was created to incorporate the pressure values to determine the resulting displacements and stresses to relate to the in-field measurements of the region in question. By comparing the displacements in the model to the field evidence, the models were calibrated, and evaluation of the likely cause of coating damage found in the field was able to be performed. Moreover, the stresses in the pipe during the event are able to be assessed which allows for damage assessments to be conducted and allows for corrective actions to take place. Transient events assessed ranged from valve openings and closures, pump start up, and vapor column collapse.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75302193","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}
Qingye Li, Chaoyong Zong, Fuwen Liu, Weihao Zhou, Xueguan Song
Safety valves as the last barrier of the pressure vessel and piping system ensure the stability of the whole system. However, there are specific situations where valves may not operate properly, which can have a significant impact on the safety of the entire system. The reason for this is a lack of understanding of the dynamic characteristics of valves, of which fluid forces are the most critical factor. In this paper, a high-precision test rig was built to test steady-state fluid forces of a direct-acting relief valve, where proportional-integral-derivative control (PID) control was applied in order to obtain more accurate multi-stage flow rates adjustments. In addition, a adjustment mechanism has been designed to obtain a more accurate valve opening. Based on this test rig, the steady-state fluid force at different openings and different flow rates are conducted, the relationship between fluid forces, flow rates and pressure drop of the valve is analyzed from the test data, which provide an in-depth understanding of the dynamic characteristics of the valves.
{"title":"Experimental Study of Fluid Forces on Direct-Acting Relief Valves","authors":"Qingye Li, Chaoyong Zong, Fuwen Liu, Weihao Zhou, Xueguan Song","doi":"10.1115/pvp2022-84469","DOIUrl":"https://doi.org/10.1115/pvp2022-84469","url":null,"abstract":"\u0000 Safety valves as the last barrier of the pressure vessel and piping system ensure the stability of the whole system. However, there are specific situations where valves may not operate properly, which can have a significant impact on the safety of the entire system. The reason for this is a lack of understanding of the dynamic characteristics of valves, of which fluid forces are the most critical factor. In this paper, a high-precision test rig was built to test steady-state fluid forces of a direct-acting relief valve, where proportional-integral-derivative control (PID) control was applied in order to obtain more accurate multi-stage flow rates adjustments. In addition, a adjustment mechanism has been designed to obtain a more accurate valve opening. Based on this test rig, the steady-state fluid force at different openings and different flow rates are conducted, the relationship between fluid forces, flow rates and pressure drop of the valve is analyzed from the test data, which provide an in-depth understanding of the dynamic characteristics of the valves.","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":"88726385","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 Explosive Destruction System (EDS), which was developed at Sandia National Laboratories, is a portable system used by the US Army to destroy recovered chemical munitions on site. The latest containment vessel is larger, much heavier and is expected to contain an explosive load over twice that of previous versions. The explosive rating for the vessel, based on the BPVC, is 24 pounds TNT for up to 1,131 detonations. The EDS vessel consists of a stainless steel, thick wall cylindrical body with large flat doors on each end which contains the explosive detonation and the subsequent chemical treatment of the chemical agent. The vessel is sealed with a metal seal gasket located between each door and the cylinder. A three-part clamping system is used to secure each door to the cylinder at each end. One of the design challenges for the EDS vessel is to ensure that the doors do not leak when the shock loads from the potentially very significant explosive loads impact the door. Previous versions of EDS vessels have experienced measurable transient displacement between the door and the vessel flanges that challenged the metal seal gasket to maintain a seal. To address the opening of the gap between the flanges during blast loadings, the door clamping system has been modified for this latest design referred to as P3. Only minor changes to the design were required and none to the operating procedure. Computer modeling of the new design predicts a significant reduction in the separation of the flanges when compared to a previous EDS vessels of similar design.
{"title":"Design Modifications to the Explosive Destruction System Closure System","authors":"J. Ludwigsen, J. Stofleth, M. Tribble, R. Crocker","doi":"10.1115/pvp2022-82285","DOIUrl":"https://doi.org/10.1115/pvp2022-82285","url":null,"abstract":"\u0000 The Explosive Destruction System (EDS), which was developed at Sandia National Laboratories, is a portable system used by the US Army to destroy recovered chemical munitions on site. The latest containment vessel is larger, much heavier and is expected to contain an explosive load over twice that of previous versions. The explosive rating for the vessel, based on the BPVC, is 24 pounds TNT for up to 1,131 detonations.\u0000 The EDS vessel consists of a stainless steel, thick wall cylindrical body with large flat doors on each end which contains the explosive detonation and the subsequent chemical treatment of the chemical agent. The vessel is sealed with a metal seal gasket located between each door and the cylinder. A three-part clamping system is used to secure each door to the cylinder at each end.\u0000 One of the design challenges for the EDS vessel is to ensure that the doors do not leak when the shock loads from the potentially very significant explosive loads impact the door. Previous versions of EDS vessels have experienced measurable transient displacement between the door and the vessel flanges that challenged the metal seal gasket to maintain a seal. To address the opening of the gap between the flanges during blast loadings, the door clamping system has been modified for this latest design referred to as P3. Only minor changes to the design were required and none to the operating procedure. Computer modeling of the new design predicts a significant reduction in the separation of the flanges when compared to a previous EDS vessels of similar design.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79664826","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 presents a numerical study on pipes ductile fracture mechanical response using a phenomenological computational damage model. The damage is controlled by an initiation criterion dependent on the stress triaxiality and the Lode angle parameter, and a post-initiation damage law to eliminate each finite element from the mesh. Experimental tests were carried out to calibrate the elastoplastic response, damage parameters and validate the FEM models. The tested geometries were round bars having smooth and notched cross-section, flat notched specimens under axial tensile loads, and fracture toughness tests in deeply cracked bending specimens SE(B) and compact tension samples C(T). The calibrated numerical procedure was applied to execute a parametric study in pipes with circumferential surface cracks subjected to tensile and internal pressure loads simultaneously. The effects of the variation of geometric parameters and the load applications on the pipes strain capacity were investigated. The influence of longitudinal misalignment between adjacent pipes was also investigated.
{"title":"Numerical Investigation of Ductile Fracture in Pipelines Under Complex Loading Using a Phenomenological Damage Model","authors":"Iago S. Santos, D. Sarzosa","doi":"10.1115/pvp2021-62017","DOIUrl":"https://doi.org/10.1115/pvp2021-62017","url":null,"abstract":"\u0000 This paper presents a numerical study on pipes ductile fracture mechanical response using a phenomenological computational damage model. The damage is controlled by an initiation criterion dependent on the stress triaxiality and the Lode angle parameter, and a post-initiation damage law to eliminate each finite element from the mesh. Experimental tests were carried out to calibrate the elastoplastic response, damage parameters and validate the FEM models. The tested geometries were round bars having smooth and notched cross-section, flat notched specimens under axial tensile loads, and fracture toughness tests in deeply cracked bending specimens SE(B) and compact tension samples C(T). The calibrated numerical procedure was applied to execute a parametric study in pipes with circumferential surface cracks subjected to tensile and internal pressure loads simultaneously. The effects of the variation of geometric parameters and the load applications on the pipes strain capacity were investigated. The influence of longitudinal misalignment between adjacent pipes was also investigated.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73875034","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 practical applications, the stress status of expanded tubes is a critical parameter to control leakage and stress corrosion cracking. Therefore, it is important to study and analyze the stress distribution generated from tube expansion. Unfortunately, there are only a few theoretical approaches available for estimating the stress distribution of formed tubes, especially for cases where the expansion is achieved with spherical and oval dies. In this study, 3/8 stainless steel and copper tubes were expanded with an oval die in a designed test workbench, and the tangential and longitudinal strains were monitored during the expansion process. A new analytical approach is developed to estimate the stresses and strains in the expanded tube during the expansion process. The different expanded zones are treated using different theories. An axisymmetric finite element model as a numerical approach is used to analyze the stresses based on a multi-linear kinematic hardening behavior to validate the analytical approach. In addition, the stresses in the expanded tube and the push force of the die are also provided by the analytical, numerical and experimental approaches. Finally, the results from the three approaches are in a relatively good agreement.
{"title":"Stress Analysis of Tubes During Die Expansion Process","authors":"Zijian Zhao, A. Bouzid","doi":"10.1115/pvp2021-61724","DOIUrl":"https://doi.org/10.1115/pvp2021-61724","url":null,"abstract":"\u0000 In practical applications, the stress status of expanded tubes is a critical parameter to control leakage and stress corrosion cracking. Therefore, it is important to study and analyze the stress distribution generated from tube expansion. Unfortunately, there are only a few theoretical approaches available for estimating the stress distribution of formed tubes, especially for cases where the expansion is achieved with spherical and oval dies.\u0000 In this study, 3/8 stainless steel and copper tubes were expanded with an oval die in a designed test workbench, and the tangential and longitudinal strains were monitored during the expansion process. A new analytical approach is developed to estimate the stresses and strains in the expanded tube during the expansion process. The different expanded zones are treated using different theories. An axisymmetric finite element model as a numerical approach is used to analyze the stresses based on a multi-linear kinematic hardening behavior to validate the analytical approach.\u0000 In addition, the stresses in the expanded tube and the push force of the die are also provided by the analytical, numerical and experimental approaches. Finally, the results from the three approaches are in a relatively good agreement.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78028223","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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