A. Recuero, Markian P. Petkov, B. Spencer, Pierre-Alexandre Juan
Predicting creep crack growth (CCG) of flaws found during operation in high-temperature alloy components is essential for assessing the remaining lifetime of those components. While defect assessment procedures are available for this purpose in design codes, these are limited in their range of applicability. This study assesses the application of a local damage-based finite-element methodology as a more general technique for the prediction of CCG at high temperatures on a variety of structural configurations. Numerical results for stainless steel 316H, which are validated against experimental data, show the promise of this approach. This integration of continuum damage mechanics (CDM) based methodologies, together with adequate inelastic models, into assessment procedures can therefore inform the characterization of CCG under complex operating conditions, while avoiding excessive conservatism. This article shows that such modeling frameworks can be calibrated to experimental data and used to demonstrate that the degree of tri-axiality ahead of a growing creep crack affects its rate of growth. The framework is also successfully employed in characterizing CCG in a realistic reactor pressure vessel geometry under an arbitrary loading condition. These results are particularly relevant to the nuclear power industry for defect assessment and inspections as part of codified practices of structural components with flaws in high-temperature reactors.
{"title":"Continuum Damage Mechanics Modeling Of High-Temperature Flaw Propagation: Application To Creep Crack Growth In 316H Standardized Specimens And Nuclear Reactor Components","authors":"A. Recuero, Markian P. Petkov, B. Spencer, Pierre-Alexandre Juan","doi":"10.1115/1.4062953","DOIUrl":"https://doi.org/10.1115/1.4062953","url":null,"abstract":"\u0000 Predicting creep crack growth (CCG) of flaws found during operation in high-temperature alloy components is essential for assessing the remaining lifetime of those components. While defect assessment procedures are available for this purpose in design codes, these are limited in their range of applicability. This study assesses the application of a local damage-based finite-element methodology as a more general technique for the prediction of CCG at high temperatures on a variety of structural configurations. Numerical results for stainless steel 316H, which are validated against experimental data, show the promise of this approach. This integration of continuum damage mechanics (CDM) based methodologies, together with adequate inelastic models, into assessment procedures can therefore inform the characterization of CCG under complex operating conditions, while avoiding excessive conservatism. This article shows that such modeling frameworks can be calibrated to experimental data and used to demonstrate that the degree of tri-axiality ahead of a growing creep crack affects its rate of growth. The framework is also successfully employed in characterizing CCG in a realistic reactor pressure vessel geometry under an arbitrary loading condition. These results are particularly relevant to the nuclear power industry for defect assessment and inspections as part of codified practices of structural components with flaws in high-temperature reactors.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42997818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The stress field, constraint effect and fracture mode transition at crack tip of mixed mode I-II-III inclination surface crack under compression have been investigated. The effects of geometrical configurations (relative crack depth and aspect ratio), friction coefficient and biaxial scale factor on stress intensity factor (KII and KIII) and in-plane constraint parameter T-stress are quantitatively studied, the stress field at different crack inclination angles under tension and compression are compared, and the failure mode at special locations along crack front of inclination surface crack are analyzed according to the generalized maximum tangential stress criterion(GMTS). The relative crack depth has slight effect on stress intensity factor and T-stress, and aspect ratio has significant effect on stress intensity factor and T-stress. The friction coefficient decreases the magnitude of stress intensity factor and increases the magnitude of T-stress, the greater the crack inclination angle is, the more pronounced the effect is when crack inclination angle greater than 30°. The stress distribution around crack tip under tension and compression is completely different. At free surface, the crack will failure in-plane shear mode II sliding crack, and at the deepest part of crack, the crack will start as an out-plane shear mode III tearing crack under compression.
{"title":"Investigation Of Constraint Effect And Fracture Mode For Mixed Mode Inclination Surface Crack In Infinite Plate Under Compression","authors":"Q. Pei, Lizhu Jin, Chang-yu Zhou, Xiao-hua He","doi":"10.1115/1.4062952","DOIUrl":"https://doi.org/10.1115/1.4062952","url":null,"abstract":"\u0000 The stress field, constraint effect and fracture mode transition at crack tip of mixed mode I-II-III inclination surface crack under compression have been investigated. The effects of geometrical configurations (relative crack depth and aspect ratio), friction coefficient and biaxial scale factor on stress intensity factor (KII and KIII) and in-plane constraint parameter T-stress are quantitatively studied, the stress field at different crack inclination angles under tension and compression are compared, and the failure mode at special locations along crack front of inclination surface crack are analyzed according to the generalized maximum tangential stress criterion(GMTS). The relative crack depth has slight effect on stress intensity factor and T-stress, and aspect ratio has significant effect on stress intensity factor and T-stress. The friction coefficient decreases the magnitude of stress intensity factor and increases the magnitude of T-stress, the greater the crack inclination angle is, the more pronounced the effect is when crack inclination angle greater than 30°. The stress distribution around crack tip under tension and compression is completely different. At free surface, the crack will failure in-plane shear mode II sliding crack, and at the deepest part of crack, the crack will start as an out-plane shear mode III tearing crack under compression.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41560226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sameer Abdul Rehman, S. El Bouzidi, O. Elbanhawy, Marwan Hassan, D. Weaver
Recent experimental investigations have shown that tube arrays can become unstable in the streamwise direction. This is contrary to the long-held notion that fluidelastic instability is only a concern in the direction transverse to the flow. The possibility of the streamwise fluidelastic instability (FEI) as a potential threat to the integrity of tube bundles was confirmed by the recent failures of newly installed replacement steam generators. A number of investigations were conducted to uncover the nature of this mechanism. A theoretical framework was developed by Hassan and Weaver (2016) to model streamwise fluidelastic instability in a bundle of flexible tubes. The model utilized a simple time lag expression for the flow channel area perturbation. The current work aims at developing a numerical model to precisely predict the flow perturbation characteristics in a tube bundle due to streamwise tube motion. Flow simulations were carried out for single phase fluid flow in a parallel triangle tube bundle array with 1.2, 1.5 and 1.7 pitch to diameter ratios. The numerical model was validated against numerical and experimental results available in the FEI literature. Simulations were carried out for a range of reduced flow velocities. The model results showed that the upstream flow perturbation magnitude and phase are different from those obtained in the downstream of the moving tube. The obtained flow perturbation characteristics were implemented in the Hassan and Weaver (2016) model and the streamwise FEI threshold was predicted.
最近的实验研究表明，管阵在流向上可能变得不稳定。这与长期持有的观点相反，即流体弹性不稳定性只与流动的横向方向有关。最近新安装的更换蒸汽发生器的故障证实了流向流体弹性不稳定性(FEI)可能对管束的完整性构成潜在威胁。为了揭示这一机制的本质，进行了一些调查。Hassan和Weaver(2016)开发了一个理论框架来模拟一束柔性管中的流向流体弹性不稳定性。该模型对流道面积扰动采用了简单的时滞表达式。目前的工作旨在建立一个数值模型，以精确预测管束中由于顺流运动引起的流动扰动特性。对节径比分别为1.2、1.5和1.7的平行三角形管束阵列中单相流体的流动进行了模拟。数值模型与FEI文献中的数值和实验结果进行了验证。在一定的降低流速范围内进行了模拟。模型结果表明，动管上游的扰动幅度和相位与下游的有所不同。在Hassan and Weaver(2016)模型中实现获得的流动扰动特征，并预测流向FEI阈值。
{"title":"Numerical Prediction Of The Streamwise Fluidelastic Instability","authors":"Sameer Abdul Rehman, S. El Bouzidi, O. Elbanhawy, Marwan Hassan, D. Weaver","doi":"10.1115/1.4062918","DOIUrl":"https://doi.org/10.1115/1.4062918","url":null,"abstract":"\u0000 Recent experimental investigations have shown that tube arrays can become unstable in the streamwise direction. This is contrary to the long-held notion that fluidelastic instability is only a concern in the direction transverse to the flow. The possibility of the streamwise fluidelastic instability (FEI) as a potential threat to the integrity of tube bundles was confirmed by the recent failures of newly installed replacement steam generators. A number of investigations were conducted to uncover the nature of this mechanism. A theoretical framework was developed by Hassan and Weaver (2016) to model streamwise fluidelastic instability in a bundle of flexible tubes. The model utilized a simple time lag expression for the flow channel area perturbation. The current work aims at developing a numerical model to precisely predict the flow perturbation characteristics in a tube bundle due to streamwise tube motion. Flow simulations were carried out for single phase fluid flow in a parallel triangle tube bundle array with 1.2, 1.5 and 1.7 pitch to diameter ratios. The numerical model was validated against numerical and experimental results available in the FEI literature. Simulations were carried out for a range of reduced flow velocities. The model results showed that the upstream flow perturbation magnitude and phase are different from those obtained in the downstream of the moving tube. The obtained flow perturbation characteristics were implemented in the Hassan and Weaver (2016) model and the streamwise FEI threshold was predicted.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46895390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The deformation and dynamic response of multi-layer cylindrical composed of an inner shell and fourteen outer layers under external blast loads of different TNT equivalency weights were studied. A numerical model using thermo-viscoplastic constitutive model and considering fluid-structure coupling between explosion wave and structure was developed. The displacement in axial direction and cross-section as well as the effective strain responses were analyzed to demonstrate the potential deformation of shell structure. Results demonstrate that different materials cause inconsistent displacement and separation to develop in inner and outer shell. In order to address the problem that the displacement of inner shell is hard to measure due to the shielding and covering of outer shell, a theoretical formula for calculating the maximum displacement of inner shell was developed. The deflection process and stress triaxiality histories of inner shell were investigated, and the results showed that compressive stress is the primary cause of plastic deformation. Additionally, the delamination that appeared in the outer shell was discussed, and it was revealed that there are two factors of delamination: 1) Stress wave spread across adjacent layers in the opposite way because steel belts were wound in the opposite direction between the two adjacent layers;2) Outer layers experienced uneven compressive loads. The results will be helpful to provide a reference for the intrinsic safety design of such multi-layer cylindrical structures for hydrogen storage, etc…
{"title":"Deformation And Dynamic Response Of Steel Belt Staggered Multi-Layer Cylindrical Shell Under External Blast Loading","authors":"Yuanqi Liu, Yang Du, F. Zhou, Zhao Zhang","doi":"10.1115/1.4062919","DOIUrl":"https://doi.org/10.1115/1.4062919","url":null,"abstract":"\u0000 The deformation and dynamic response of multi-layer cylindrical composed of an inner shell and fourteen outer layers under external blast loads of different TNT equivalency weights were studied. A numerical model using thermo-viscoplastic constitutive model and considering fluid-structure coupling between explosion wave and structure was developed. The displacement in axial direction and cross-section as well as the effective strain responses were analyzed to demonstrate the potential deformation of shell structure. Results demonstrate that different materials cause inconsistent displacement and separation to develop in inner and outer shell. In order to address the problem that the displacement of inner shell is hard to measure due to the shielding and covering of outer shell, a theoretical formula for calculating the maximum displacement of inner shell was developed. The deflection process and stress triaxiality histories of inner shell were investigated, and the results showed that compressive stress is the primary cause of plastic deformation. Additionally, the delamination that appeared in the outer shell was discussed, and it was revealed that there are two factors of delamination: 1) Stress wave spread across adjacent layers in the opposite way because steel belts were wound in the opposite direction between the two adjacent layers;2) Outer layers experienced uneven compressive loads. The results will be helpful to provide a reference for the intrinsic safety design of such multi-layer cylindrical structures for hydrogen storage, etc…","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48749094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashok Kumar, S. Pandey, Abir Bhattacharya, D. Fydrych, Sachin Sirohi, C. Pandey
The present work aimed to investigate the microstructure and mechanical properties of the dissimilar shielded metal arc welded (SMAW) joint of Alloy 617 and P92 steel for advanced ultra-supercritical (AUSC) boilers. The SMAW joint was produced using three different types of electrodes, namely ENiCrFe-3, ENiCrMo-3 and ENiCrCoMo-1. During microstructural observation of the welded joints, no possible cracking was detected in the weldments. The dissimilar metal welds (DMWs) obtained using the ENiCrCoMo-1 electrode showed the maximum tensile strength, while the minimum was obtained for the ENiCrFe-3 electrode. Among all the electrodes, the ENiCrFe-3 electrode exhibited the maximum impact toughness, while the minimum was obtained for ENiCrCoMo-1 electrodes. Based on microstructure and mechanical characterization, the ENiCrFe-3 electrode was selected as the best one among all to produce the DMW of Alloy 617 and P92 steel.
{"title":"Selection of Electrode Material for Inconel 617/P92 Steel SMAW Dissimilar Welds","authors":"Ashok Kumar, S. Pandey, Abir Bhattacharya, D. Fydrych, Sachin Sirohi, C. Pandey","doi":"10.1115/1.4062794","DOIUrl":"https://doi.org/10.1115/1.4062794","url":null,"abstract":"\u0000 The present work aimed to investigate the microstructure and mechanical properties of the dissimilar shielded metal arc welded (SMAW) joint of Alloy 617 and P92 steel for advanced ultra-supercritical (AUSC) boilers. The SMAW joint was produced using three different types of electrodes, namely ENiCrFe-3, ENiCrMo-3 and ENiCrCoMo-1. During microstructural observation of the welded joints, no possible cracking was detected in the weldments. The dissimilar metal welds (DMWs) obtained using the ENiCrCoMo-1 electrode showed the maximum tensile strength, while the minimum was obtained for the ENiCrFe-3 electrode. Among all the electrodes, the ENiCrFe-3 electrode exhibited the maximum impact toughness, while the minimum was obtained for ENiCrCoMo-1 electrodes. Based on microstructure and mechanical characterization, the ENiCrFe-3 electrode was selected as the best one among all to produce the DMW of Alloy 617 and P92 steel.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47911698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiming Cao, Hui Ma, Xumin Guo, Han Ge, Hui Li, Junzhe Lin
The fluid conveying pipelines are often subjected to internal fluid fluctuation excitation in hydraulic pump and external base excitation from aeroengine rotor. To investigate the acceleration response of pipeline and pressure pulsation response of fluid, the vibration tests of pipeline under base excitation, fluid fluctuation excitation and multi-excitation are conducted. A set of test bench and test scheme of pipeline system under multi-excitation are designed. The test data are collected by piezoelectric pressure sensor and three-direction acceleration sensor. By analyzing the test data, the following results can be obtained: Under base excitation, the internal fluid still has weak pressure pulsation response even without fluid fluctuation excitation. However, the pressure pulsation response remains unchanged with the increase of base excitation amplitude. Under fluid fluctuation excitation, the amplitudes of vibration responses at fluid fundamental frequency fp increase with the increase of pump pressure except at 9 MPa and 15 MPa. The natural frequency of pipeline is close to 3fp when the pump pressure is 9 MPa and 15 MPa respectively, and the pipeline system will have resonance. Under multi-excitation, the amplitudes of vibration responses are close to the superimposed amplitudes of two single source excitations at fb=175 Hz and fp=298 Hz. The vibration responses appear beat vibration at fb=298 Hz and fp=297.6 Hz. The relevant test scheme and test data analysis adopted in this paper have important reference value for the in-depth study of pipeline vibration under multi-excitation and engineering practice.
{"title":"Experimental Study On Pressure Pulsation and Acceleration Response of Fluid Conveying Pipeline Under Multi-Excitation","authors":"Yiming Cao, Hui Ma, Xumin Guo, Han Ge, Hui Li, Junzhe Lin","doi":"10.1115/1.4062751","DOIUrl":"https://doi.org/10.1115/1.4062751","url":null,"abstract":"\u0000 The fluid conveying pipelines are often subjected to internal fluid fluctuation excitation in hydraulic pump and external base excitation from aeroengine rotor. To investigate the acceleration response of pipeline and pressure pulsation response of fluid, the vibration tests of pipeline under base excitation, fluid fluctuation excitation and multi-excitation are conducted. A set of test bench and test scheme of pipeline system under multi-excitation are designed. The test data are collected by piezoelectric pressure sensor and three-direction acceleration sensor. By analyzing the test data, the following results can be obtained: Under base excitation, the internal fluid still has weak pressure pulsation response even without fluid fluctuation excitation. However, the pressure pulsation response remains unchanged with the increase of base excitation amplitude. Under fluid fluctuation excitation, the amplitudes of vibration responses at fluid fundamental frequency fp increase with the increase of pump pressure except at 9 MPa and 15 MPa. The natural frequency of pipeline is close to 3fp when the pump pressure is 9 MPa and 15 MPa respectively, and the pipeline system will have resonance. Under multi-excitation, the amplitudes of vibration responses are close to the superimposed amplitudes of two single source excitations at fb=175 Hz and fp=298 Hz. The vibration responses appear beat vibration at fb=298 Hz and fp=297.6 Hz. The relevant test scheme and test data analysis adopted in this paper have important reference value for the in-depth study of pipeline vibration under multi-excitation and engineering practice.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48806456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract It is a key issue to clarify failure mode of piping in nuclear power plants and its safety margin included in the design practice. In this study, a series of dynamic failure tests of a thin wall tee for sodium-cooled fast reactors was conducted. Some discussions related to the thin wall tee are provided on the failure mode under seismic load, dynamic response behavior, accuracy of fatigue prediction by dynamic elastic-plastic analysis, and a safety margin of fatigue evaluation which is included in conventional design rule.
{"title":"Ultimate Strength of a Thin Wall Tee for Sodium Cooled Fast Reactors Under Seismic Loads","authors":"Tomoyoshi Watakabe, Hideki Takahashi","doi":"10.1115/1.4062675","DOIUrl":"https://doi.org/10.1115/1.4062675","url":null,"abstract":"Abstract It is a key issue to clarify failure mode of piping in nuclear power plants and its safety margin included in the design practice. In this study, a series of dynamic failure tests of a thin wall tee for sodium-cooled fast reactors was conducted. Some discussions related to the thin wall tee are provided on the failure mode under seismic load, dynamic response behavior, accuracy of fatigue prediction by dynamic elastic-plastic analysis, and a safety margin of fatigue evaluation which is included in conventional design rule.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135525265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A statistical model to estimate the distribution characteristics of Charpy absorbed energy in the transition temperature range was proposed based on the variation in fracture toughness addressed by the Master Curve and the relationship between fracture toughness and Charpy absorbed energy associated with the Charpy Master Curve. Charpy absorbed energy in the transition temperature range can be well approximated by both the Weibull and normal distributions, and the parameters to determine the shape of the distributions (scale and shape parameters of the Weibull distribution, mean and standard deviation of the normal distribution) can be deductively defined as the functions of two independent variables, median of the fracture toughness and the difference between reference temperature and Charpy reference temperature. A series of Charpy impact tests were conducted under the same conditions to obtain the characteristics of the variation in Charpy absorbed energy for a reactor pressure vessel steel SQV2A base metal, and the experimental variation was reasonably predicted by the proposed model.
{"title":"Statistical Distribution Model of Charpy Absorbed Energy in Transition Temperature Range for Reactor Pressure Vessel Steel","authors":"N. Miura, T. Shinko","doi":"10.1115/1.4062674","DOIUrl":"https://doi.org/10.1115/1.4062674","url":null,"abstract":"\u0000 A statistical model to estimate the distribution characteristics of Charpy absorbed energy in the transition temperature range was proposed based on the variation in fracture toughness addressed by the Master Curve and the relationship between fracture toughness and Charpy absorbed energy associated with the Charpy Master Curve. Charpy absorbed energy in the transition temperature range can be well approximated by both the Weibull and normal distributions, and the parameters to determine the shape of the distributions (scale and shape parameters of the Weibull distribution, mean and standard deviation of the normal distribution) can be deductively defined as the functions of two independent variables, median of the fracture toughness and the difference between reference temperature and Charpy reference temperature. A series of Charpy impact tests were conducted under the same conditions to obtain the characteristics of the variation in Charpy absorbed energy for a reactor pressure vessel steel SQV2A base metal, and the experimental variation was reasonably predicted by the proposed model.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44039434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract For the assessment of welds under high-temperature conditions in the creep or creep-fatigue regimes, the knowledge of the damage location and its temporal evolution is of high importance. The local failure behavior of weld joints is not reflected in design guidelines using weld reduction factors or in typical assessment approaches. The evaluation of local strains and stresses in the heat affected zone (HAZ) is essential for a more detailed consideration of weld behavior and has a high potential for improvement of design and inspection guidelines. In this paper, an overview of current developments in the assessment of weld joints is given. Uni-axial creep, component tests, low cycle fatigue (LCF), and creep-fatigue experiments with base material, weld joints and microstructure simulated HAZ material are presented. The use of test results of microstructure simulated HAZ material allows the parameter identification of numerical material models for the HAZ and improves the simulation of the local stress and strain behavior of weld joints. Two assessment methods, one for creep and one for fatigue/creep-fatigue were presented, based on the local behavior determined by the numerical simulations. The assessment approach for pure creep loads was validated using several uni-axial creep tests and two component tests. The approach for the fatigue/creep-fatigue loads is still in the developmental stage but the first results were presented and further areas for improvement were identified.
{"title":"Damage Assessment of Similar Martensitic Welds Under Creep, Fatigue, and Creep-Fatigue Loading","authors":"Thorben Bender, Andreas Klenk, Stefan Weihe","doi":"10.1115/1.4062396","DOIUrl":"https://doi.org/10.1115/1.4062396","url":null,"abstract":"Abstract For the assessment of welds under high-temperature conditions in the creep or creep-fatigue regimes, the knowledge of the damage location and its temporal evolution is of high importance. The local failure behavior of weld joints is not reflected in design guidelines using weld reduction factors or in typical assessment approaches. The evaluation of local strains and stresses in the heat affected zone (HAZ) is essential for a more detailed consideration of weld behavior and has a high potential for improvement of design and inspection guidelines. In this paper, an overview of current developments in the assessment of weld joints is given. Uni-axial creep, component tests, low cycle fatigue (LCF), and creep-fatigue experiments with base material, weld joints and microstructure simulated HAZ material are presented. The use of test results of microstructure simulated HAZ material allows the parameter identification of numerical material models for the HAZ and improves the simulation of the local stress and strain behavior of weld joints. Two assessment methods, one for creep and one for fatigue/creep-fatigue were presented, based on the local behavior determined by the numerical simulations. The assessment approach for pure creep loads was validated using several uni-axial creep tests and two component tests. The approach for the fatigue/creep-fatigue loads is still in the developmental stage but the first results were presented and further areas for improvement were identified.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134996307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shen Zx, Zhu Jindan, Wang Du, Xu Jia-min, Huang Huangdong, Zhang Haoqi, Cai Penghui, Chen Hu
Failure risk assessment of pressure vessels and piping systems is an important part of their integrity management. Obviously, there are many shortcomings in risk analysis using only traditional procedures, which are mostly qualitative or conservative by nature. This study develops a novel limit analysis method using quantitative magnetic measurements to determine the failure risk of steel vessels. Firstly, the correlation between the physico-mechanical properties of a pressurized steel cylinder and the magnetic coercive force was obtained by hydraulic tests, it is found that increasing internal pressure leads to an increase in the coercive force, and the magnetomechanical behaviour can be described by a linear general expression. By solving the inverse problem, it is possible to diagnose the transition of the structure to the yield region or the fracture region based on the measurements of coercivity, which enables us to conduct the risk assessment prior to the failure of a pressurized cylinder, validated by a full-scale hydrostatic burst test. Finally, a quantitative criteria for identifying the structural failure of the pressurized cylinder was established based on coercivity measurements.
{"title":"Failure Risk Assessment Of Pressurized Cylinder By Magnetic Measurements","authors":"Shen Zx, Zhu Jindan, Wang Du, Xu Jia-min, Huang Huangdong, Zhang Haoqi, Cai Penghui, Chen Hu","doi":"10.1115/1.4062587","DOIUrl":"https://doi.org/10.1115/1.4062587","url":null,"abstract":"\u0000 Failure risk assessment of pressure vessels and piping systems is an important part of their integrity management. Obviously, there are many shortcomings in risk analysis using only traditional procedures, which are mostly qualitative or conservative by nature. This study develops a novel limit analysis method using quantitative magnetic measurements to determine the failure risk of steel vessels. Firstly, the correlation between the physico-mechanical properties of a pressurized steel cylinder and the magnetic coercive force was obtained by hydraulic tests, it is found that increasing internal pressure leads to an increase in the coercive force, and the magnetomechanical behaviour can be described by a linear general expression. By solving the inverse problem, it is possible to diagnose the transition of the structure to the yield region or the fracture region based on the measurements of coercivity, which enables us to conduct the risk assessment prior to the failure of a pressurized cylinder, validated by a full-scale hydrostatic burst test. Finally, a quantitative criteria for identifying the structural failure of the pressurized cylinder was established based on coercivity measurements.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48519156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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