{"title":"Mean Stress Correction for Fatigue Life of Carbon Steel: Proposal of Non-Closure Model","authors":"M. Kamaya","doi":"10.1115/pvp2019-93253","DOIUrl":"https://doi.org/10.1115/pvp2019-93253","url":null,"abstract":"\u0000 Influence of the mean stress on fatigue life was investigated for carbon steel. Uni-axial fatigue tests were conducted by stress and strain-controlled conditions at room temperature. The fatigue life was reduced by applying the mean stress for the same stress amplitude. The fatigue life exhibited better correlation with the strain range rather than the stress amplitude. Increase in strain range caused by applying the mean stress correlated well with the decrease in the fatigue life. It was assumed that the mean stress effect on the fatigue life was brought about by the change in crack growth rate caused by applying the mean stress. The mean stress enhanced crack mouth opening and accelerated the crack growth. The non-closure model, in which the crack mouth is assumed not to be closed even at the minimum peak stress, was proposed.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"370 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114859492","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}
B. Millet, K. Ebrahimi, James Lu, K. Kirkpatrick, Bryan Mosher
{"title":"A Study of the Conservatism in ASME BPVC Section VIII Division 2 Opening Design for External Pressure","authors":"B. Millet, K. Ebrahimi, James Lu, K. Kirkpatrick, Bryan Mosher","doi":"10.1115/pvp2019-93565","DOIUrl":"https://doi.org/10.1115/pvp2019-93565","url":null,"abstract":"\u0000 In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger.\u0000 This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"55 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128954183","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}
{"title":"New Model for Ductile Rupture Under Cyclic Loading Conditions","authors":"A. Remmal, S. Marie, J. Leblond","doi":"10.1115/pvp2019-93836","DOIUrl":"https://doi.org/10.1115/pvp2019-93836","url":null,"abstract":"\u0000 Experiments have shown that ductile failure occurs sooner under cyclic loading conditions than under monotone ones. This reduction of ductility probably arises from an effect called “ratcheting of the porosity” that consists of a continued increase of the mean porosity during each cycle with the number of cycles. Improved micromechanical simulations confirmed this interpretation. The same work also contained a proof that Gurson’s classical model for porous ductile materials does not predict any ratcheting of the porosity. In a recent work [6], the authors proposed a Gurson-type “layer model” better fit than Gurson’s original one for the description of the ductile behavior under cyclic loading conditions, using the theory of sequential limit analysis. A very good agreement was obtained between the model predictions and the results of the micromechanical simulations for a rigid-hardenable material. However, the ratcheting of the porosity is a consequence of both hardening and elasticity, and sequential limit analysis is strictly applicable in the absence of elasticity. In this work, we make a proposal to take into account elasticity in the layer model through the definition of a new objective stress rate leading to an accurate expression of the porosity rate accounting for both elasticity and plasticity. This proposal is assessed through comparison of its predictions with the results of some new micromechanical simulations performed for matrices exhibiting both elasticity and all types of hardening: isotropic, kinematic and mixed, to better comply with the hypothesis made to derive the model.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"38 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130900047","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}
{"title":"Basic Design Rules for Lines in Pulsating Flow Service","authors":"Menno Eijgenhuijsen, Girish Masand","doi":"10.1115/pvp2019-93459","DOIUrl":"https://doi.org/10.1115/pvp2019-93459","url":null,"abstract":"\u0000 To avoid unacceptable vibration of suction and discharge piping for reciprocating pumps and compressors, acoustic and mechanical response analyses are to be carried out. These analyses are generally provided by the suppliers of such equipment. This paper explains the fundamentals behind an acoustic and mechanical response analysis and provides a simple set of consolidated design and engineering rules. The paper encourages application of these rules while developing the equipment and piping layout as well as pipe support configuration. The aim of these rules is to minimize the chance for the ultimate supplier’s detailed acoustic & mechanical response analysis to recommend significant changes to the design in a late stage of a project. Specific emphasis is placed on how the support stiffness affects the natural frequency of the piping system and a practical methodology is provided to account for this in pipe support span calculations. This paper also describes the process information that needs to be submitted to the supplier to conduct a meaningful acoustic as well as mechanical response analysis. Acknowledging requirements for lines in pulsating service at a late stage in the project, not providing the supplier with the required process information or a piping and support configuration that is not ‘mature’ enough will most likely result in significant delay and cost.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130309885","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}
J. Hebeisen, T. Adams, Bruce F. Dubovecky, T. Jiménez
{"title":"Repair of B31.1 Fiber Reinforced Polymer Piping System Using Carbon Fiber Reinforced Polymer","authors":"J. Hebeisen, T. Adams, Bruce F. Dubovecky, T. Jiménez","doi":"10.1115/pvp2019-93103","DOIUrl":"https://doi.org/10.1115/pvp2019-93103","url":null,"abstract":"\u0000 This paper describes the use of Carbon Fiber Reinforced Polymer (CFRP) for the repair of leaking Fiber Reinforced Polymer (FRP) pipe. The existing piping system, which is used for slurry transport, consisted of straight pipe, reducers, and elbows connected by bell and spigot joints. The piping system was evaluated for pressure, deadweight, and fluid thrust loads in accordance with B31.1 Power Piping Code and ASME BPVC Section III, Code Case N-155. The pipe leaks and joint repairs were in accordance with ASME PCC-2 and ASME BPVC, Section III, Code Case N-155. The CFRP repair was done with Aegion TYFO® Fibrwrap® carbon fiber reinforced fiber wrap (TYFO SCH-41-2X) saturated with epoxy. The repair uses the unidirectional carbon fiber installed in layers 90° to each layer. The circumferential layers are used for hoop pressure stress while the axial layers restrain axial pressure, deadweight, and fluid thrust loadings on the pipe.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130993583","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}
{"title":"Comparison of Fracture Assessments of Corrosion Pits Using Sharp and Blunt Notched Crack Procedures","authors":"C. Meek, M. Spence","doi":"10.1115/pvp2019-93297","DOIUrl":"https://doi.org/10.1115/pvp2019-93297","url":null,"abstract":"\u0000 Historically, when determining failure criteria for a cracked structure, the structure has been assessed with the crack tip assumed to be infinitely sharp. For scenarios where it can be shown that the crack tip is blunt, such as for corrosion pits, this may lead to overly pessimistic assessments which can have implications for remnant life assessments of structures.\u0000 Recent research has been carried out to evaluate structures with the crack tip as a blunt notch with a radius, and to develop a notch acuity parameter. That research led to formulae for adapting either the failure assessment curve or the failure assessment points utilising the notch acuity parameter for ferritic materials.\u0000 This paper analyses various configurations of crack and specimen geometry, crack tip notch acuity parameter and crack spacing. It takes a finite element model of a cracked structure with an infinitely sharp crack and compares the failure parameters to those of equivalent notched cracks. The comparison is completed using the formulae derived in recent literature and those determined using finite element models with the blunt notched radii at the crack tip incorporated into the model.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130998708","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}
{"title":"Analysis of a Flanged and Dished Head Assembly Used in a Horizontal Storage Tank","authors":"Mingxin Zhao","doi":"10.1115/pvp2019-93221","DOIUrl":"https://doi.org/10.1115/pvp2019-93221","url":null,"abstract":"\u0000 A nonstandard flanged and dished head is frequently used in the horizontal storage tank for quick and full access to the internal in oil and gas industry. The head is forged into an elliptical shape with a flat edge at its peripheral. The flat edge serves as a flange while the other mating half coming from the tank shell. The flange pair is installed within a C-shaped clamp and secured by compression bolts at its head side. A gasket is sandwiched between the mating surfaces of the flange pair to provide proper seal. While the head can be removed easily by unscrewing the compression bolts, this disintegrated structure does increase the complexity in component design and unique requirement for installation. The bolt compression load not only affects the pressure capacity of the storage tank, but also governs the stresses in flange pair and C-clamp. In this study, the flanged and dished head assembly has been modeled and analyzed by finite element method for stresses and gasket seal performance subject to installation and operation loads. Both elastic and elastic-plastic analysis has been performed. The tightening force of the bolts is examined against component stresses and gasket seal performance. Optimized bolt load is recommended based on acceptance criteria for stresses and leakage prevention.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122187070","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}
{"title":"Defining the How and When to Execute Single Stud Replacement (SSR) of Bolted Flanged Joints","authors":"Clay D. Rodery, S. Hamilton, N. Ferguson, G. Jung","doi":"10.1115/pvp2019-93687","DOIUrl":"https://doi.org/10.1115/pvp2019-93687","url":null,"abstract":"\u0000 Single Stud Replacement (SSR), or as currently known in ASME PCC-2 as “Hot Bolting” is the removal and replacement of studs on a bolted joint on a one at a time basis in a predetermined sequence. One of the key aspects in the successful execution of this activity is the determination of the appropriate maximum pressure governing the operation. The guidance currently provided in ASME PCC-2 is somewhat arbitrary and vague, and some clearer definition of a technical basis in this area would be valuable to industry in terms of both productivity and safety.\u0000 To provide additional clarity to this activity, a Task Group within the ASME Post Construction Subcommittee on Flanged Joint Assembly is redrafting the article detailing procedures for Single Stud Replacement. This paper discusses the work and focuses on the task of determining and documenting a technical basis for setting the limits (e.g., maximum pressure, effects of external moments, etc.) to safely execute a Single Stud Replacement operation.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117104909","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}
{"title":"A Method to Estimate Deformation Strains in the Context of Coke Drum Life Assessments: Part 1","authors":"John Huang, K. Subramanian, P. Boster, J. Bedoya","doi":"10.1115/pvp2019-93740","DOIUrl":"https://doi.org/10.1115/pvp2019-93740","url":null,"abstract":"\u0000 In this paper, an analytical method to estimate the deformation strains that can quantify the severity of bulges, as it applies to coke drums, is presented. The proposed method is based on classical shell theory and API 579-1/ASME FFS-1 (2016) procedures involving triaxiality limits. In this first part of the work, only the theoretical development is presented along with the comparison of the results from this theoretical approach with two case studies that emulate the bulging due to different loading scenarios. The developed approach is then applied to a deformed coke drum. In the next part of this paper, the application of this approach on selected in-service coke drums that are equipped with strain gages will be presented. The authors would like to emphasize the well-known fact that the coke drum is a complex pressure vessel for which any single simplified assessment technique may not be sufficient to quantify the life or fitness-for-service (FFS) of a coke drum due to the complexities associated with the various parameters that affect the mechanical integrity of the coke drum. This paper is an attempt to advance the assessment techniques that are currently utilized in the industry.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127700439","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}
{"title":"Computational Fluid Dynamics Modeling of an Experimental Thermal-Stratification Flow Case Using ABAQUS/CFD","authors":"D. Franken, S. Mohanty","doi":"10.1115/pvp2019-93932","DOIUrl":"https://doi.org/10.1115/pvp2019-93932","url":null,"abstract":"\u0000 As the fleet of Pressurized Water Reactors (PWRs) in the United States begin to reach the end of their original lifespan many of them are undergoing assessment to extend their use. In order to investigate the potential for extending the life of the plant, a system level analysis of components needs to be performed in order to ensure that age and degradation of the system will not lead to a potential safety hazard. An area in which this system level investigation is particularly important is in the surge line of the pressurizer. One possible concern is that over the life of the reactor, the surge line pipe will experience thermal stratification many times. Thermal stratification can lead to significant stresses induced on the piping and over time may result in a less than ideal safety standard. Commercially available code Abaqus CFD was used to model the thermal stratification in a pipe. The corresponding experimental results, available in literature were compared. We found there is a good correlation between the experimental and computational results. However, the results discussed in this paper are based on our preliminary effort to study the capability of ABAQUS code for CFD simulation. A detailed parametric study is one of our future work.","PeriodicalId":150804,"journal":{"name":"Volume 3: Design and Analysis","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117200939","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}