Gurumurthy Kagita, Penchala S. K. Pottem, Deepak Gupta, Gudimella G. S. Achary, Subramanyam V. R. Sripada
Pipeline design codes recognize the potential risks posed by gas pipelines by relating the factors which affect the probability of failure to consequences in particular locations. To maintain more or less uniform risk level, ASME B31.8 Code adopted risk based concepts indirectly through location classifications by specifying different design factors (DFs). Engineering Critical Assessment (ECA) of onshore natural gas pipelines in accordance with pipeline-specific methods such as API 1104 allow much deeper defects in higher class pipe, which is in contrary to the basic design concept. This is due to the lack of consideration for the higher consequences in the higher classes even though they were considered at the design stage. To ensure the failure probability within a target value, generic fitness for service standards such as API 579-1/ASME FFS-1 and BS 7910 recommend partial safety factors (PSFs) to key variables. However, there is no correlation between the design factors used during the pipeline design stage and the PSFs used for the ECA. To achieve the basic intent of design code i.e., to maintain risk level as per location classifications, this paper proposes to use PSFs based on class location. Few case studies are presented to demonstrate the proposed methodology.
{"title":"Engineering Critical Assessment (ECA) of Onshore Natural Gas Pipelines Using Partial Safety Factors (PSFs)","authors":"Gurumurthy Kagita, Penchala S. K. Pottem, Deepak Gupta, Gudimella G. S. Achary, Subramanyam V. R. Sripada","doi":"10.1115/pvp2022-84151","DOIUrl":"https://doi.org/10.1115/pvp2022-84151","url":null,"abstract":"\u0000 Pipeline design codes recognize the potential risks posed by gas pipelines by relating the factors which affect the probability of failure to consequences in particular locations. To maintain more or less uniform risk level, ASME B31.8 Code adopted risk based concepts indirectly through location classifications by specifying different design factors (DFs). Engineering Critical Assessment (ECA) of onshore natural gas pipelines in accordance with pipeline-specific methods such as API 1104 allow much deeper defects in higher class pipe, which is in contrary to the basic design concept. This is due to the lack of consideration for the higher consequences in the higher classes even though they were considered at the design stage. To ensure the failure probability within a target value, generic fitness for service standards such as API 579-1/ASME FFS-1 and BS 7910 recommend partial safety factors (PSFs) to key variables. However, there is no correlation between the design factors used during the pipeline design stage and the PSFs used for the ECA. To achieve the basic intent of design code i.e., to maintain risk level as per location classifications, this paper proposes to use PSFs based on class location. Few case studies are presented to demonstrate the proposed methodology.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86356668","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}
Relief valves act as a controlled weak point in a pressurised system to protect against the dangers of an overpressure event. As such, their sound and reliable operation is crucial to the longevity of any pressurised system. The correct operation of a safety valve is established by adhering to the overpressure and blowdown requirements, i.e. the pressures above and below the set pressure which the valve will open and close and for many ASME BPVC regulated valves these pressures are of the order of 3–10% of set pressure. Since the disc forces are directly proportional to pressure, the accuracy requirements of Computational Fluid Dynamics (CFD) prediction techniques need to be much lower to allow CFD prediction to be a reliable tool for valve design and to guide the development of the device. In this paper, the capability of CFD modelling as a design tool for relief valves used in gas service is investigated by assessing the CFD prediction of disc lift-force curves. A full force-lift curve was produced with a maximum uncertainty of 2% in the low-lift region controlling the overpressure and 1.5% in the high-lift region which controls the blowdown and is of the same order as the experimental measurement. When using ASME BPVC Section VIII as an example, where the requirements for overpressure and blowdown are 10% and 7% respectively, the current CFD modelling capabilities can predict disc forces to an acceptable fraction of the Section VIII certification requirements. However, when comparing the CFD error to ASME BPVC Section I requirements which are much stricter at 3% and 4% for overpressure and blowdown, the use of CFD is more challenging with the CFD uncertainty of the same order as the design requirements.
{"title":"CFD Based Relief Valve Design: Accuracy Requirements and CFD Capability","authors":"S. Taggart, Christopher Doyle, W. Dempster","doi":"10.1115/pvp2022-83579","DOIUrl":"https://doi.org/10.1115/pvp2022-83579","url":null,"abstract":"\u0000 Relief valves act as a controlled weak point in a pressurised system to protect against the dangers of an overpressure event. As such, their sound and reliable operation is crucial to the longevity of any pressurised system. The correct operation of a safety valve is established by adhering to the overpressure and blowdown requirements, i.e. the pressures above and below the set pressure which the valve will open and close and for many ASME BPVC regulated valves these pressures are of the order of 3–10% of set pressure. Since the disc forces are directly proportional to pressure, the accuracy requirements of Computational Fluid Dynamics (CFD) prediction techniques need to be much lower to allow CFD prediction to be a reliable tool for valve design and to guide the development of the device. In this paper, the capability of CFD modelling as a design tool for relief valves used in gas service is investigated by assessing the CFD prediction of disc lift-force curves. A full force-lift curve was produced with a maximum uncertainty of 2% in the low-lift region controlling the overpressure and 1.5% in the high-lift region which controls the blowdown and is of the same order as the experimental measurement. When using ASME BPVC Section VIII as an example, where the requirements for overpressure and blowdown are 10% and 7% respectively, the current CFD modelling capabilities can predict disc forces to an acceptable fraction of the Section VIII certification requirements. However, when comparing the CFD error to ASME BPVC Section I requirements which are much stricter at 3% and 4% for overpressure and blowdown, the use of CFD is more challenging with the CFD uncertainty of the same order as the design requirements.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81209378","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 kind of clean energy with good prospect, the demand of trans-regional transportation of hydrogen is increasing rapidly. However, due to the difficulty and high cost of pipeline transportation, tube bundle containers are more used to transport hydrogen. As the fixing device of tube bundle container, the frame structure should not only ensure that the gas cylinder can be fixed, but also meet the requirements of stiffness and strength. In order to improve the efficiency of hydrogen transportation, a new frame structure of 40-foot high pressure and large capacity tube bundle container for road transportation was designed. There are two groups of tube bundles at the front and rear of the tube bundle container, carrying 18 hydrogen storage bottles. The total hydrogen storage capacity is more than 1000kg and the pressure is 52MPa. The design process is as follows: firstly, the stress analysis of the original frame structure under four inertia force conditions was carried out, and it was found that the structure was difficult to meet the strength requirements for road transportation. Then, the beam distribution of tube bundle container frame structure was preliminarily determined by using the method of topology optimization and the geometric model of the optimized frame structure was remodeled according to the topology optimization results. Finally, the static analysis of the frame structure under various driving inertia force loads was carried out by ANSYS Workbench finite element analysis software. The results show that the designed tube bundle container frame structure meets the requirements of strength. This work provides a reference for the design and safety evaluation of similar tube bundle container frame structure products.
{"title":"Frame Structure Design of 40-Foot High Pressure and Large Capacity Hydrogen Storage Tube Bundle Container for Road Transportation","authors":"Mengjie Liu, Zhiping Chen, Zhi Cheng, Haiyang Ou","doi":"10.1115/pvp2022-84398","DOIUrl":"https://doi.org/10.1115/pvp2022-84398","url":null,"abstract":"\u0000 As a kind of clean energy with good prospect, the demand of trans-regional transportation of hydrogen is increasing rapidly. However, due to the difficulty and high cost of pipeline transportation, tube bundle containers are more used to transport hydrogen. As the fixing device of tube bundle container, the frame structure should not only ensure that the gas cylinder can be fixed, but also meet the requirements of stiffness and strength. In order to improve the efficiency of hydrogen transportation, a new frame structure of 40-foot high pressure and large capacity tube bundle container for road transportation was designed. There are two groups of tube bundles at the front and rear of the tube bundle container, carrying 18 hydrogen storage bottles. The total hydrogen storage capacity is more than 1000kg and the pressure is 52MPa. The design process is as follows: firstly, the stress analysis of the original frame structure under four inertia force conditions was carried out, and it was found that the structure was difficult to meet the strength requirements for road transportation. Then, the beam distribution of tube bundle container frame structure was preliminarily determined by using the method of topology optimization and the geometric model of the optimized frame structure was remodeled according to the topology optimization results. Finally, the static analysis of the frame structure under various driving inertia force loads was carried out by ANSYS Workbench finite element analysis software. The results show that the designed tube bundle container frame structure meets the requirements of strength. This work provides a reference for the design and safety evaluation of similar tube bundle container frame structure products.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74941611","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 recent years API 579 has provided the analyst with a detailed outline of cycle counting techniques for uni-axial loading (the Rainflow Cycle Counting (RCC) method: ASTM Standard No. E1049 three-point method) and multi-axial loading (the Wang-Brown algorithm (WBCC)). However, for vibration-based fatigue, in the absence of any time history at all; it is common in industry to assess fatigue using frequency domain techniques. The most accurate frequency domain techniques, such as the ever-popular Dirlik’s method, are optimized for a very restricted class of fatigue curve. In closed form Dirlik’s method is only applicable to the class of fatigue curves that exhibit a constant fatigue stress exponent over the number of cycles. In more general settings the validity of the Dirlik probability density is most accurate when the curve power (i.e. ‘m’ where m ≡ h−1 and ‘h’ is found in API 579 Table 14B.3 or ASME VIII Div. 2 Table 3-F.2) is ∼3.0, and is arguably only applicable between 2 to 5. API 579 Method A provides the ‘smooth bar’ fatigue curves, which are described by a polynomial relationship in which m will often approach 20 at very large numbers of cycles. The alternative technique of API 579 Method C for assessing welds, does comply with the fatigue curve restrictions (i.e. m = 3.13 for ferritic and stainless steel and m = 3.61 for Aluminum). However, this method could arguably be augmented with an increased stress exponent at large numbers of cycles and beyond that an infinite life (e.g. BS EN 13445-3 where N = 5 × 106 is infinite life for monotonic loading and a transition to m = 5 for variable amplitude loading followed by infinite life at N = 108). While it is not the claim of this paper, this would be conceptually consistent with the minimum propagating crack size of fracture mechanics, which is the theoretical basis for the Method C approach. This paper follows on from previous work (PVP2020-21392 [1]) and presents a detailed algorithm for constructing fatigue curve specific cycle count correlations in the spirit of the Dirlik cycle counting. As such these correlations are primarily sensitive to the spectral moments. These correlations are based on specific functions of the spectral moments, functions that have been found to produce reliably low scatter with respect to RCC. In addition to the traditional 5 spectral moments, we show that, at very large fatigue curve stress exponents, the spectral entropy can be used to enhance the accuracy of the estimated cycle count. These parameters (5 spectral moments and spectral entropy) are very cheap to calculate in the spectral domain, making this method very computationally efficient. The algorithm also makes it possible for the user to choose the confidence interval on the scatter data. In this way, with some care, the user can naturally account for the inherent hyper-sensitivity of the high cycle part of the fatigue curve to atypically large stress events. Both of these characteristics make
近年来，API 579为分析人员提供了单轴载荷循环计数技术(雨流循环计数(RCC)方法)的详细大纲。E1049三点法)和多轴加载(Wang-Brown算法(WBCC))。然而，对于基于振动的疲劳，在没有任何时间历史的情况下;在工业中，使用频域技术评估疲劳是很常见的。最精确的频域技术，如广受欢迎的Dirlik方法，都是针对非常有限的疲劳曲线进行优化的。在封闭形式下，Dirlik方法仅适用于在循环次数上表现出恒定疲劳应力指数的疲劳曲线。在更一般的设置中，当曲线功率(即m≡h−1和h)在API 579表14B中找到时，Dirlik概率密度的有效性是最准确的。3或ASME VIII Div. 2表3- f .2)为~ 3.0，并且可以说仅适用于2至5之间。API 579方法A提供了“光滑条”疲劳曲线，该曲线由多项式关系描述，其中m在大量循环时通常接近20。API 579方法C用于评估焊缝的替代技术确实符合疲劳曲线限制(即铁素体和不锈钢的m = 3.13，铝的m = 3.61)。然而，这种方法可以在大量循环时增加应力指数，并在无限寿命之外进行扩展(例如BS EN 13445-3，其中N = 5 × 106是单调加载的无限寿命，对于可变振幅加载过渡到m = 5，然后是N = 108的无限寿命)。虽然这不是本文的主张，但这在概念上与断裂力学的最小扩展裂纹尺寸是一致的，这是方法C方法的理论基础。本文在前人工作(PVP2020-21392[1])的基础上，提出了一种基于Dirlik循环计数精神构建疲劳曲线特定循环计数相关性的详细算法。因此，这些相关性主要对谱矩敏感。这些相关性基于谱矩的特定函数，这些函数已被发现相对于RCC产生可靠的低散射。除了传统的5个谱矩外，我们还表明，在非常大的疲劳曲线应力指数下，谱熵可以用来提高估计周期数的准确性。这些参数(5个谱矩和谱熵)在谱域中的计算非常便宜，使得该方法的计算效率非常高。该算法还使用户可以选择散点数据的置信区间。这样，只要稍加注意，用户就可以很自然地解释疲劳曲线的高周部分对非典型大应力事件固有的超敏感性。这两个特点使该技术适用于快速虚拟原型和随后的设计优化在现实世界中快速周转适合服务补救应用。
{"title":"An Efficient Method of Estimating Spectral Fatigue Damage for Low RMS Stress Ranges and Arbitrary Fatigue Curves","authors":"B. Francis, D. Mair","doi":"10.1115/pvp2022-84596","DOIUrl":"https://doi.org/10.1115/pvp2022-84596","url":null,"abstract":"\u0000 In recent years API 579 has provided the analyst with a detailed outline of cycle counting techniques for uni-axial loading (the Rainflow Cycle Counting (RCC) method: ASTM Standard No. E1049 three-point method) and multi-axial loading (the Wang-Brown algorithm (WBCC)). However, for vibration-based fatigue, in the absence of any time history at all; it is common in industry to assess fatigue using frequency domain techniques.\u0000 The most accurate frequency domain techniques, such as the ever-popular Dirlik’s method, are optimized for a very restricted class of fatigue curve. In closed form Dirlik’s method is only applicable to the class of fatigue curves that exhibit a constant fatigue stress exponent over the number of cycles. In more general settings the validity of the Dirlik probability density is most accurate when the curve power (i.e. ‘m’ where m ≡ h−1 and ‘h’ is found in API 579 Table 14B.3 or ASME VIII Div. 2 Table 3-F.2) is ∼3.0, and is arguably only applicable between 2 to 5.\u0000 API 579 Method A provides the ‘smooth bar’ fatigue curves, which are described by a polynomial relationship in which m will often approach 20 at very large numbers of cycles. The alternative technique of API 579 Method C for assessing welds, does comply with the fatigue curve restrictions (i.e. m = 3.13 for ferritic and stainless steel and m = 3.61 for Aluminum). However, this method could arguably be augmented with an increased stress exponent at large numbers of cycles and beyond that an infinite life (e.g. BS EN 13445-3 where N = 5 × 106 is infinite life for monotonic loading and a transition to m = 5 for variable amplitude loading followed by infinite life at N = 108). While it is not the claim of this paper, this would be conceptually consistent with the minimum propagating crack size of fracture mechanics, which is the theoretical basis for the Method C approach.\u0000 This paper follows on from previous work (PVP2020-21392 [1]) and presents a detailed algorithm for constructing fatigue curve specific cycle count correlations in the spirit of the Dirlik cycle counting. As such these correlations are primarily sensitive to the spectral moments. These correlations are based on specific functions of the spectral moments, functions that have been found to produce reliably low scatter with respect to RCC. In addition to the traditional 5 spectral moments, we show that, at very large fatigue curve stress exponents, the spectral entropy can be used to enhance the accuracy of the estimated cycle count.\u0000 These parameters (5 spectral moments and spectral entropy) are very cheap to calculate in the spectral domain, making this method very computationally efficient. The algorithm also makes it possible for the user to choose the confidence interval on the scatter data. In this way, with some care, the user can naturally account for the inherent hyper-sensitivity of the high cycle part of the fatigue curve to atypically large stress events. Both of these characteristics make ","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83963566","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}
Nicole Farrugia, D. Camilleri, B. Ellul, M. Muscat
Filament winding has been extensively used to fabricate fibre reinforced composite pipes. The fibres are primarily oriented in such a way to increase the structural efficiency of the pipes to withstand internal pressure, that namely load the pipes in the hoop direction. However, the various intricate pipe systems and connections will also subject these pipes to torsional and bending loads. In this study different fibre orientation lay-up sequences consisting of four E-Glass /polyester resin layers were fabricated using a standard four-axis filament winding machine and experimentally subjected to torsion and bending load tests. During the curing process the samples were also vacuum bagged to minimise the void content. The respective volume fractions are also identified through ignition loss tests. The load versus deformation and ultimate failure load were recorded. The onset of first ply failure was also identified through acoustic/vibration measurements and observable differences in load/deformation plots. Different failure modes were observed ranging from buckling failure to matrix failure. The primary failure mode for pipes subject to bending was either compressive or tensile failure at the upper or lower strands of the pipe as a result of the imposed bending stresses. On the other hand, buckling or shear failure was observed in the pipes subject to torsional loading. The best fibre orientation based on loading conditions was identified. In the case of bending, the load carrying capacity increased when fibres are oriented closer to the axial direction, however care is to be taken to ensure that the pipes do not buckle. In the case of torsional loading, pipes with fibres oriented at 45° were able to sustain the highest load.
{"title":"Filament Wound Composite Pipes Subject to Torsion and Bending Loads","authors":"Nicole Farrugia, D. Camilleri, B. Ellul, M. Muscat","doi":"10.1115/pvp2022-84680","DOIUrl":"https://doi.org/10.1115/pvp2022-84680","url":null,"abstract":"\u0000 Filament winding has been extensively used to fabricate fibre reinforced composite pipes. The fibres are primarily oriented in such a way to increase the structural efficiency of the pipes to withstand internal pressure, that namely load the pipes in the hoop direction. However, the various intricate pipe systems and connections will also subject these pipes to torsional and bending loads. In this study different fibre orientation lay-up sequences consisting of four E-Glass /polyester resin layers were fabricated using a standard four-axis filament winding machine and experimentally subjected to torsion and bending load tests. During the curing process the samples were also vacuum bagged to minimise the void content. The respective volume fractions are also identified through ignition loss tests. The load versus deformation and ultimate failure load were recorded. The onset of first ply failure was also identified through acoustic/vibration measurements and observable differences in load/deformation plots. Different failure modes were observed ranging from buckling failure to matrix failure. The primary failure mode for pipes subject to bending was either compressive or tensile failure at the upper or lower strands of the pipe as a result of the imposed bending stresses. On the other hand, buckling or shear failure was observed in the pipes subject to torsional loading. The best fibre orientation based on loading conditions was identified. In the case of bending, the load carrying capacity increased when fibres are oriented closer to the axial direction, however care is to be taken to ensure that the pipes do not buckle. In the case of torsional loading, pipes with fibres oriented at 45° were able to sustain the highest load.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81399185","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 recent years, a large number of failure assessment models (FAMs), like SINTAP, BS7910 and API 579 have been developed to evaluate the structural integrity of pipelines. Based on them, various software, such as PRO-LOCA, PROST, xLPR, etc, have been established to evaluate the safety and reliability of pipelines. However, which of these codes fit best the user’s requirements is a difficult problem because it depends on scientific as well as on personal criteria. Therefore, in this paper, we propose several multiple evaluation criteria to discuss the integrity assessment codes. Furthermore, we apply mathematical methods to evaluate the prediction performance (PP) of the codes PRO-LOCA and PROST. The PP covers seven criteria: correlation, multimodality, dispersion, risk, conservativeness, robustness and accuracy. The correlation, multimodality and dispersion reflect the stability of the predicted results, while risk, conservativeness, robustness and accuracy illustrate distributional location characteristics (DLC) of the prediction accuracy (PA).
{"title":"An Evaluation of Probabilistic Integrity Assessment Codes","authors":"Lingyun Guo, M. Niffenegger","doi":"10.1115/pvp2022-84277","DOIUrl":"https://doi.org/10.1115/pvp2022-84277","url":null,"abstract":"\u0000 In recent years, a large number of failure assessment models (FAMs), like SINTAP, BS7910 and API 579 have been developed to evaluate the structural integrity of pipelines. Based on them, various software, such as PRO-LOCA, PROST, xLPR, etc, have been established to evaluate the safety and reliability of pipelines. However, which of these codes fit best the user’s requirements is a difficult problem because it depends on scientific as well as on personal criteria. Therefore, in this paper, we propose several multiple evaluation criteria to discuss the integrity assessment codes. Furthermore, we apply mathematical methods to evaluate the prediction performance (PP) of the codes PRO-LOCA and PROST.\u0000 The PP covers seven criteria: correlation, multimodality, dispersion, risk, conservativeness, robustness and accuracy. The correlation, multimodality and dispersion reflect the stability of the predicted results, while risk, conservativeness, robustness and accuracy illustrate distributional location characteristics (DLC) of the prediction accuracy (PA).","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89584091","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}
Yuki Mihara, S. Kataoka, Atsushi Okami, Kyohei Takahashi
EPC contractors / manufacturers design and use the lugs attached on the skirt for tailing of vertical vessels. To avoid the overstressing and deformation of the skirt base ring due to tailing load, the reinforcing beams attached inside the base ring may be considered. Since the design rules for tailing devices are not described in ASME BPVC Section VIII, the soundness of the tailing design could be left to the judgement of individual parties. In past projects, the deformation of the skirt base ring during lifting work at construction site occurred and gave huge impact on construction schedule and cost. As per the theoretical calculation for the design of the skirt base ring reinforcements, the beams are generally considered as “rigid” structure. Based on the results in this paper, it can be said that the base ring may be overstressed and largely deformed if the axial stiffness of the reinforcing beams is not properly taken into the consideration of tailing design, especially for large diameter vessels. This paper provides the basic concept and practical design consideration of the skirt base ring subject to tailing load by investigating the tendency of bending moment and residual plastic deformation of the skirt base ring with several types of reinforcing beam arrangement.
{"title":"Study on Skirt Base Ring Reinforcement for Tailing of Vertical Vessels","authors":"Yuki Mihara, S. Kataoka, Atsushi Okami, Kyohei Takahashi","doi":"10.1115/pvp2022-84499","DOIUrl":"https://doi.org/10.1115/pvp2022-84499","url":null,"abstract":"\u0000 EPC contractors / manufacturers design and use the lugs attached on the skirt for tailing of vertical vessels. To avoid the overstressing and deformation of the skirt base ring due to tailing load, the reinforcing beams attached inside the base ring may be considered. Since the design rules for tailing devices are not described in ASME BPVC Section VIII, the soundness of the tailing design could be left to the judgement of individual parties. In past projects, the deformation of the skirt base ring during lifting work at construction site occurred and gave huge impact on construction schedule and cost.\u0000 As per the theoretical calculation for the design of the skirt base ring reinforcements, the beams are generally considered as “rigid” structure. Based on the results in this paper, it can be said that the base ring may be overstressed and largely deformed if the axial stiffness of the reinforcing beams is not properly taken into the consideration of tailing design, especially for large diameter vessels.\u0000 This paper provides the basic concept and practical design consideration of the skirt base ring subject to tailing load by investigating the tendency of bending moment and residual plastic deformation of the skirt base ring with several types of reinforcing beam arrangement.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89210423","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}
Combustible gas accounts for an increasing proportion of energy in countries. As the main transportation tool of combustible gas, the safety of pipeline has always been the focus of researchers. When the gas explodes, the accident consequences are greatly affected by the pipeline structure. The study on the hydrogen explosion characteristics of a typical pipe structure (elbow structure) is carried out in the paper. The results show that in pipes with large elbow angles, the flame front can form local cavity regions as flame passes through the elbows. The influence of elbow structure on flame propagation is mainly concentrated in the middle and late stages. In the middle stage, the elbow structure creates a relatively closed space in advance, so that the speed peak-2 occurs earlier than the straight pipe. In the later stage, the acceleration effect produced by the outer wall (concave wall) plays a leading role, and the flame accelerates for the third time after passing through the elbow. There is an interactive relationship between the development of the explosion overpressure and the flame propagation in the elbow.
{"title":"Numerical Simulation on the Influence of Elbow Structure on Hydrogen Flame Propagation Process in Pipes","authors":"Yuan Mei, J. Shuai, Sheng Qi, Zhonghong Huang","doi":"10.1115/pvp2022-84144","DOIUrl":"https://doi.org/10.1115/pvp2022-84144","url":null,"abstract":"\u0000 Combustible gas accounts for an increasing proportion of energy in countries. As the main transportation tool of combustible gas, the safety of pipeline has always been the focus of researchers. When the gas explodes, the accident consequences are greatly affected by the pipeline structure. The study on the hydrogen explosion characteristics of a typical pipe structure (elbow structure) is carried out in the paper. The results show that in pipes with large elbow angles, the flame front can form local cavity regions as flame passes through the elbows. The influence of elbow structure on flame propagation is mainly concentrated in the middle and late stages. In the middle stage, the elbow structure creates a relatively closed space in advance, so that the speed peak-2 occurs earlier than the straight pipe. In the later stage, the acceleration effect produced by the outer wall (concave wall) plays a leading role, and the flame accelerates for the third time after passing through the elbow. There is an interactive relationship between the development of the explosion overpressure and the flame propagation in the elbow.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77694949","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}
Ismael Allouche, Qian Zheng, N. Yoosef-Ghodsi, Matt Fowler, S. Adeeb
Pipelines subject to ground deformations produced by geohazard loads carry high importance on pipeline analysis, design, and assessment due to risk of structural failure. An appropriate approach for evaluation is the finite element method (FEM), providing efficient and sophisticated results. Methods proposed by Zheng et al. (2021) using finite element analysis (FEA) software Abaqus/Standard provide highly accurate results by simulating a displacement-controlled analysis of buried steel pipes subject to ground displacement of varying magnitudes and direction. This paper aims to further develop this pipe strain demand assessment by including variable effects of internal pressure and temperature of steel pipes buried in soils of different stiffness. The developed strain demand criterion considers inelastic material behaviour for different grades of steel pipe, as well as bi-linear soil force-displacement interaction, accounting for soil plasticity (ALA, 2001). Assuming the effects of thermal expansion are negligible prior to ground motion initiation, the pipe loads can be assessed by modelling a pipeline with initial temperature and pressure loads, followed by a ground motion in a series of steps. Several case studies were performed by modelling an X65 grade pipeline subject to ground displacements varying from 100 to 1000 mm, across a length at the midsection of the pipe. Simulations are assessed with a specified temperature increase, and internal pressure required to induce an operating hoop stress of up to 80% of the specified minimum yield strength (SMYS). By assessing the pipeline in soils of different stiffness (low, intermediate, high) at different increments of ground displacement, an accurate representation of the material stress/strain response can be acquired for each respective case. This research may provide guidance for further studies of pipelines involving internal pressure & temperature.
{"title":"Combined Effect of Pressure, Temperature and Soil Stiffness on Pipeline Strain Demand in Geohazard Zones","authors":"Ismael Allouche, Qian Zheng, N. Yoosef-Ghodsi, Matt Fowler, S. Adeeb","doi":"10.1115/pvp2022-83754","DOIUrl":"https://doi.org/10.1115/pvp2022-83754","url":null,"abstract":"\u0000 Pipelines subject to ground deformations produced by geohazard loads carry high importance on pipeline analysis, design, and assessment due to risk of structural failure. An appropriate approach for evaluation is the finite element method (FEM), providing efficient and sophisticated results. Methods proposed by Zheng et al. (2021) using finite element analysis (FEA) software Abaqus/Standard provide highly accurate results by simulating a displacement-controlled analysis of buried steel pipes subject to ground displacement of varying magnitudes and direction. This paper aims to further develop this pipe strain demand assessment by including variable effects of internal pressure and temperature of steel pipes buried in soils of different stiffness. The developed strain demand criterion considers inelastic material behaviour for different grades of steel pipe, as well as bi-linear soil force-displacement interaction, accounting for soil plasticity (ALA, 2001). Assuming the effects of thermal expansion are negligible prior to ground motion initiation, the pipe loads can be assessed by modelling a pipeline with initial temperature and pressure loads, followed by a ground motion in a series of steps. Several case studies were performed by modelling an X65 grade pipeline subject to ground displacements varying from 100 to 1000 mm, across a length at the midsection of the pipe. Simulations are assessed with a specified temperature increase, and internal pressure required to induce an operating hoop stress of up to 80% of the specified minimum yield strength (SMYS). By assessing the pipeline in soils of different stiffness (low, intermediate, high) at different increments of ground displacement, an accurate representation of the material stress/strain response can be acquired for each respective case. This research may provide guidance for further studies of pipelines involving internal pressure & temperature.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"6 5‐6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91417980","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}
Due to the aging of facilities, Oil and Chemical industries in Japan has been longing for using API 579-1/ASME FFS-1 [1] Part 4 and Part 5 assessment over decades. However, most of equipment are subjected to Japanese High Pressure Gas Safety Law so our industry needed to pass through the discussion in a local committee. In the local committee, there was a conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms. The conflict had been a stumbling block against the formal permission to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment technology. In 2021, throughout the long term effort of cross industry task team led by authors supported by API579-1/ASME Joint Committee on Fitness-For-Service members, the conflict has been solved in the local committee. Effective from April 1st, 2022, Oil and Chemical industry in Japan got a formal approval from the government to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment for equipment subjected to High Pressure Gas Safety Law. Authors noticed similar conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms, is also found in societies outside of Japan occasionally. Those factors are sometimes referred as “bulging factor” that sounds like those are simple conversion factors between flat plate stress and cylinder stress. However, it is not a whole picture of the factor as discussed in this paper. Therefore, it would be beneficial for future improvement of Fitness-for-Service technology to share our outcomes on the correct significance of Mt and Ms including our Lr discussion on API579-1/ASME FFS-1 Part 9 Crack Like Flaw assessment taking this opportunity. In addition, authors studied the relative relationship between plastic zone length and distance to major stress discontinuity associated with the discussion. This might be beneficial to be shared for a future discussion too. Through this paper, significance of Mt and Ms, including derivation of Ms reinforced by FEM analysis, will be discussed. Also, plastic zone size model that can be used for a future discussion on required Lmsd, distance to major stress discontinuity, will be introduced.
由于设施老化，日本石油和化学工业几十年来一直渴望使用API 579-1/ASME FFS-1 [1] Part 4和Part 5评估。然而，大部分设备都受日本高压气体安全法的约束，因此我们的行业需要通过地方委员会的讨论。在当地委员会中，对叶面校正因子Mt和地表校正因子ms的重要性存在冲突，这一冲突阻碍了API 579-1/ASME FFS-1 Part 4和Part 5评估技术的正式使用。2021年，在API579-1/ASME健身服务联合委员会成员支持下，通过作者领导的跨行业任务小组的长期努力，解决了地方委员会内部的冲突。自2022年4月1日起，日本石油和化学工业获得政府正式批准，对高压气体安全法规定的设备使用API 579-1/ASME FFS-1第4部分和第5部分评估。作者注意到，在叶面因子(Mt)和表面校正因子(Ms)的重要性上，类似的冲突也偶尔在日本以外的社会中发现。这些因素有时被称为“胀形因素”，听起来像是平板应力和圆柱体应力之间的简单转换因素。然而，这并不是本文所讨论的因素的全貌。因此，借此机会分享我们关于Mt和Ms的正确意义的成果，包括我们对API579-1/ASME FFS-1 Part 9裂纹样缺陷评估的Lr讨论，将有利于未来健身服务技术的改进。此外，作者还研究了塑性区长度与主应力不连续距离的相对关系。这对于将来的讨论也是有益的。通过本文，将讨论Mt和Ms的意义，包括有限元分析增强Ms的推导。此外，还将介绍塑性区尺寸模型，该模型可用于将来讨论所需的Lmsd，即到主应力不连续的距离。
{"title":"Reorganize Significance of Mt, Ms and Plastic Zone Size Against LMSD Under Plastic Collapse Regime","authors":"Yoichi Ishizaki, Futoshi Yonekawa","doi":"10.1115/pvp2022-85187","DOIUrl":"https://doi.org/10.1115/pvp2022-85187","url":null,"abstract":"\u0000 Due to the aging of facilities, Oil and Chemical industries in Japan has been longing for using API 579-1/ASME FFS-1 [1] Part 4 and Part 5 assessment over decades. However, most of equipment are subjected to Japanese High Pressure Gas Safety Law so our industry needed to pass through the discussion in a local committee. In the local committee, there was a conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms. The conflict had been a stumbling block against the formal permission to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment technology.\u0000 In 2021, throughout the long term effort of cross industry task team led by authors supported by API579-1/ASME Joint Committee on Fitness-For-Service members, the conflict has been solved in the local committee. Effective from April 1st, 2022, Oil and Chemical industry in Japan got a formal approval from the government to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment for equipment subjected to High Pressure Gas Safety Law.\u0000 Authors noticed similar conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms, is also found in societies outside of Japan occasionally. Those factors are sometimes referred as “bulging factor” that sounds like those are simple conversion factors between flat plate stress and cylinder stress. However, it is not a whole picture of the factor as discussed in this paper. Therefore, it would be beneficial for future improvement of Fitness-for-Service technology to share our outcomes on the correct significance of Mt and Ms including our Lr discussion on API579-1/ASME FFS-1 Part 9 Crack Like Flaw assessment taking this opportunity. In addition, authors studied the relative relationship between plastic zone length and distance to major stress discontinuity associated with the discussion. This might be beneficial to be shared for a future discussion too.\u0000 Through this paper, significance of Mt and Ms, including derivation of Ms reinforced by FEM analysis, will be discussed. Also, plastic zone size model that can be used for a future discussion on required Lmsd, distance to major stress discontinuity, will be introduced.","PeriodicalId":23700,"journal":{"name":"Volume 2: Computer Technology and Bolted Joints; Design and Analysis","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87217740","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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