Academic literature on the topic 'Work hardening program'
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Journal articles on the topic "Work hardening program"
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Johnson, Leslie Stratton, Gail Archer-Heese, Deanne L. Caron-Powles, and Tracey M. Dowson. "Work hardening: Outdated fad or effective intervention?" WORK: A Journal of Prevention, Assessment & Rehabilitation 16, no. 3 (2001): 235–43. https://doi.org/10.3233/wor-2001-00156.
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{\it Objectives}: The purpose of this outcome measurement study was to determine the effectiveness of a work hardening program as measured by the participants' work status at three months after program completion. Predictors of successful return to work were explored. {\it Study design}: The sequential case series design was employed, and data were gathered at three points: the initial work hardening assessment, the discharge assessment, and three months post-discharge from the work hardening program. Seventy-nine participants were included. {\it Results}: Eighty-two percent (82%) of the clients who completed a work hardening program reported that they were working in some capacity three months after program completion. They listed their employment status in 5 sub-categories. Significant predictors of employment included ``single'' marital status, lower perceived disability scores at program entry, reduction in reported pain during program duration, and funding source. {\it Conclusion}: Work hardening remains an effective treatment strategy which promotes successful return to the workplace. Ongoing analyses of these programs is imperative.
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Sang, Lau Shun, and Li Ping Ying Eria. "Outcome evaluation of work hardening program for manual workers with work-related back injury." WORK: A Journal of Prevention, Assessment & Rehabilitation 25, no. 4 (2005): 297–305. https://doi.org/10.3233/wor-2005-00467.
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Objective: The purpose of this study was to investigate the effectiveness of a 12-week work hardening program designed for back injured workers. Study design: In this study, 32 subjects were recruited. Pre- and post-assessment results were used to measure the program effectiveness. The intensity of the work hardening program was based on the overloading training principle. Subjects were contacted by phone three months after the program completion for their work status. Result: The findings of this study suggested that there was a significant difference in the subjects' physical demand characteristic level before and after the work hardening program. Seventy-five percent of the subjects who completed the work hardening program were able to resume employment. Conclusion: The rate of returning to work for back injured workers in this study was comparable to that of other studies. Thus, this study suggests that the overloading principle should be used in designing a work hardening program to improve clients' physical function.
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Nisarga, N. Chilakwad, and Rais A. Rizvi. Syed. "EFFECTIVENESS OF WORK HARDENING PROGRAM IN BANKERS HAVING WORK-RELATED CHRONIC NECK PAIN IN BANGALORE." VIMS Journal of Physical Therapy 1, no. 2 (2019): 79–85. https://doi.org/10.5281/zenodo.3753857.
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Backgroundand Objectives: Disorders caused due to working patterns or work related stresses are called occupa-tional disorders.Work related neck disorders are common problems in office workers,especially among those who are intensive computer users.Banking occupation requires a lot of stereotyped movements of the arms, hands and fin-gers,and repetitive occupational tasks with short cycle times have become more and more frequent in modern tech-nology as seen in this type of occupation with many of them associated with increased rates of chronic neck pain. Work place rehabilitation is necessary for work related to chronic neck pain in bankers.The objective of the study was to evaluate the effectiveness of the Work hardening program along with Conservative treatment versus Conservative treatment alone in bankers having Chronic neck pain. Methods:60 bankers having Chronic neck pain were randomly allocated in two groups.Group A received Conservative treatment alone and Group B received a Work hardening program along with Conservative treatment.The outcome was assessed in terms of Neck Disability Scale (NDI) scores and Numeric Pain rating Scale (NPRS) scores pre interven-tion and post intervention. Results:Both the interventions of conservative treatment and conservative treatment with a work hardening pro-gram were individually effective.But,the subjects treated with a conservative with work hardening program was sig-nificantly effective than conservative alone. Interpretation and Conclusion:The present study concludes that both treatment protocols were effective in reduc-ing Chronic neck pain.Further it was also noticed that Group B was more effective in improving neck disability and in reducing pain than Group A.Thus applying for the treatment protocol Work hardening program along with Conserva-tive treatment was better than Conservative treatment applied alone.
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Ricke, Stacey A., Paul J. Chara, and Mary M. Johnson. "Work Hardening: Evidence for Success of a Program." Psychological Reports 77, no. 3_suppl (1995): 1077–78. http://dx.doi.org/10.2466/pr0.1995.77.3f.1077.
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The effectiveness of a work hardening program in facilitating gains in physical strength and return to work in 40 chronic low back-pain clients was assessed. Statistically significant gains in physical strength were found. Also, 27 of the 32 clients reached by follow-up telephone calls returned to work full time.
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Voaklander, Donald C., A. Paul Beaulne, and Rene A. Lessard. "Factors related to outcome following a work hardening program." Journal of Occupational Rehabilitation 5, no. 2 (1995): 71–85. http://dx.doi.org/10.1007/bf02109911.
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Ambrosius, Frank M., Barbara K. Rounds, Peter B. Herkner, Mark A. Dekraker, and Steven R. Bartz. "Reactivation of Injured Workers Involved in a Work-Hardening Program." Work 4, no. 1 (1994): 28–34. http://dx.doi.org/10.3233/wor-1994-4105.
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Rytökoski, Ulla, Aaro Rissanen, and Seija Talo. "Progressive work hardening program for patients with chronic low back pain." International Journal of Rehabilitation Research 12, no. 3 (1989): 347. http://dx.doi.org/10.1097/00004356-198909000-00023.
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Cooper, J. E., R. Tate, and A. Yassi. "Work hardening in an early return to work program for nurses with back injury." Work 8, no. 2 (1997): 149–56. http://dx.doi.org/10.3233/wor-1997-8205.
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Christine Scully-Palmer. "Outcome study: An industrial rehabilitation program." WORK: A Journal of Prevention, Assessment & Rehabilitation 15, no. 1 (2000): 21–23. https://doi.org/10.3233/wor-2000-00100.
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A review of work hardening outcome research reveals a wide range of return to work statistics between 50% are forcing therapy services to objectively quantify their successes to ensure a future in health care. Work Venture has been maintaining program outcome statistics since 1994. In this report, 1997 and 1998 return to work statistics are documented and compared to multiple programs. Work Venture's average annual return to gainful employment percentages for 1997 are 61.2% at 6 months, and in 1998, 76.8% discharge. Many factors are involved in successful return to work with workers compensation claims. Due to these factors it is difficult to compare one program's results with another. It is recommended that a uniform method of collecting and presenting data be developed to ensure valid comparison.
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Greenberg, Susan N., and Raymond P. Bello. "The Work Hardening Program and Subsequent Return to Work of a Client With Low Back Pain." Journal of Orthopaedic & Sports Physical Therapy 24, no. 1 (1996): 37–45. http://dx.doi.org/10.2519/jospt.1996.24.1.37.
Full textDissertations / Theses on the topic "Work hardening program"
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Liedtke-Hendrickson, Valette. "The Effects of Self-Monitoring and Health Locus of Control on Improvement in a Work Hardening Program." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc330824/.
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This study examined the effects of self-monitoring behavior and health locus of control on improvement in a work hardening program. The subjects included 22 male and 18 female outpatients in a hospital-based rehabilitation program. Subjects were classified as having an internal or external health locus of control, and were randomly assigned to either a self-monitoring or a non-self-monitoring group. Improvement was assessed via objective performance data and self-ratings of perceived improvement. The results indicated that individuals identified as having an internal health locus of control did not show greater gains in physical functioning or perceived improvement relative to externally oriented individuals. Additionally, those subjects participating in self-monitoring activities were no different from non-self-monitoring subjects in terms of improvement in exercise activities or perceived improvement. The results also indicated no interaction between health locus of control and the presence or absence of self-monitoring. It was suggested that other factors such as workman's compensation, pain patient characteristics, low self-concept, and severe stress may have proved more powerful influences on patient improvement than internal health locus of control or self-monitoring. It was also suggested that rehabilitation programs might benefit from creating structured environments in which patients receive frequent staff feedback and reinforcement for improvement. Monitoring small, discrete, easily attainable goals might prove more effective than monitoring mood, pain, etc. In addition, teaching specific internal health locus of control behaviors to patients may help them improve their self-concepts and progress. Further research is needed to explore the roles that pain patient personality characteristics, self-concept, and stress play in the progress of patients in a work hardening program.
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Chang, Chia-Ning, and 張迦寧. "The effectiveness of a work hardening program on low back pain patients." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/32034260142972370702.
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碩士<br>國立臺灣大學<br>職能治療研究所<br>96<br>The purpose of this research was to examine the short and long term effectiveness of the work hardening program on the pain score, lifting and carrying capacity, and work status of the low back pain clients. Simultaneously, the relationship within the demographic, social, psychological factors, and the work status were studied as well. The subjects were 23 low back pain clients without job or with decreased workability. The clients receiving standard work hardening were experimental group (13 people) while the others couldn’t finish the program or received <5 days training were considered as control group (10 people). Both groups were examined with National Taiwan University Hospital Functional Capacity Evaluation (NTUH-FCE) and the Numerical Pain Scale (NRS) before the treatment. The experimental group was evaluated again at the time of discharge. The work status of all the clients was collected by phone at 1, 3, 6, and 12 months after discharge. Averagely three years after the discharge, the clients were recalled to complete the NTUH-FCE, NRS, and the work and health status questionnaire. Results revealed that after work hardening, the carrying capacity, lifting capacity, lifting match ratio, and the pain score of the experimental group improved. At the time of the long term follow up, subjects in the experiemental group had the same results as those of discharge, which meant that the effectiveness of the work hardening program lasted for at least 3 years. The study found that the people with longer injury days or sick leave days had more difficulty in returning to work and while the female clients and the ones with <25% work ability loss could keep their job easier. The primary limitations of this study were the small sample size and the methods of data collection. The study design should be refined. Finally, this study supported the effectiveness of the work hardening programfor the employees with low back pain to return to work safely.
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Chen, Wei Jung, and 陳威榮. "A study of satisfaction for work hardening program among work injured employees of a hospital in northern Taiwan: Hospital-based service model." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/12824422503927805050.
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碩士<br>長庚大學<br>職能治療學系<br>100<br>Existing evidences show many benefits of work hardening program for work injured employees, such as improving workers’ functional recovery, rate of return-to-work, and reducing the expense of vocational rehabilitation. Although the program has been implemented for several years in Taiwan, few researches investigated the level of satisfaction for the program from the view points of injured workers. The aim of this study is exploring the satisfaction of work injured employees for work hardening program under hospital-based model in northern Taiwan.
This is a retrospective empirical study. Both qualitative and quantitative data were collected. Customized-designed questionnaire for assessing subjective views were distributed to 50 cases. Ten out of fifty voluntary workers were arranged for in-depth interview by a qualified occupational therapist twice. Commercial statistical software, SPSS 12.0, was used. Statistical significant level was set at p≦0.05. The interview data were categorized into domains and were analyzed and reported descriptively.
The results showed that the subjects reported improvement in confidence of their work abilities, work satisfactions, and opportunities of returning to work. Their score of satisfactions toward work hardening program were rated as moderate to high on a four-point Likert scale. The data further showed that the worker had difficulty approaching work hardening program. The workers also reported the need to involve their employer, psychologist and legal consultant to be in the process of training. The results of this study can only be applied to northern part of Taiwan and be referenced by institutions at the other part of the country.
Conference papers on the topic "Work hardening program"
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Pike, Lee M., Paul E. Manning, and Edward L. Hibner. "Severe Sour Gas Testing of a High Strength, Corrosion Resistant Ni-Cr-Mo Alloy." In CORROSION 2012. NACE International, 2012. https://doi.org/10.5006/c2012-01702.
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Abstract This paper will present the results of a severe sour gas test program on a new high strength, corrosion-resistant alloy for oil and gas applications. This alloy is capable of yield strengths from 160 to 200 ksi (1100 to 1380 MPa) or more through either cold working or cold work + age-hardening. This high strength is achieved while leaving the material with excellent ductility and toughness – far surpassing alloys strengthened through traditional precipitation hardening. Alternatively, the alloy can be produced in the annealed + age-hardened condition, which though providing a somewhat lower yield strength (~120 ksi/830 MPa) has even higher ductility. In addition to these desirable mechanical properties, the alloy exhibits exceptional sour gas resistance. In this paper, we will present the results of sour gas testing (both SSR and 90-day C-ring tests) at temperatures ranging from 401 to 550°F (205 to 288°C). Tests were conducted both with and without the presence of elemental sulfur. The results of these tests have been used to successfully incorporate high-strength N07022 alloy into the MR0175/ISO 15156 standard.
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Ashida, Yugo, Peter L. Andresen, and Gary S. Was. "Effect of Yield Strength on Stress Corrosion Cracking Growth in Neutron-Irradiated Stainless Steels." In CORROSION 2014. NACE International, 2014. https://doi.org/10.5006/c2014-4231.
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Abstract Mechanical properties such as yield strength and hardness of irradiated stainless steels can be significantly changed by increasing irradiation dose. An understanding of the effects of mechanical properties on crack growth in neutron-irradiated stainless steels is required for identifying the irradiation assisted stress corrosion cracking (IASCC) mechanism and for establishing strategies for IASCC mitigation. In this study, experimental crack growth rate (CGR) data of irradiated alloys reported by the university and the Cooperative IASCC Research (CIR) program were correlated with hardness and yield strength, as well as with microstructural and microchemical variables such as loops, precipitates, and Cr depletion and Si enrichment at grain boundaries. It was found that the increase in CGR was proportional to the increase in yield strength and hardness caused by irradiation, but not directly related to many other variables. To simulate the effect of irradiation on CGR, finite element method (FEM) analyses on yield strength increased alloys were conducted to estimate the size and shape of plastic zone at the crack tip. Yield strengths of 250, 500, 750 and 1000 MPa were used to simulate stainless steels at different irradiation doses. An 8 mm round compact tension (RCT) specimen under constant K control at 15 MPa∙m1/2 was used in the FEM simulation. The CGR in high strength irradiated alloys correlates with the decrease in plastic zone size, the decrease in tensile plastic strain and strain increment, and the increase in tensile “opening” stress. In addition, similarities and differences between cold work hardening and radiation hardening are discussed.
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Marchebois, Hervé, Christoph Bosch, and Ali Smith. "SSC Limits of TMCP Line Pipes." In CORROSION 2021. AMPP, 2021. https://doi.org/10.5006/c2021-16516.
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Abstract Large diameter TMCP (Thermo-Mechanically Controlled Process) pipelines have recently shown detrimental local variations in mechanical properties. Additionally, industry experience demonstrated that API(1) 5L / ISO(2) 3183 and NACE MR 0175 / ISO 15156 compliant TMCP linepipe presented increased ID surface hardness, commonly known as hardspots or hard layers. These surface anomalies are difficult to detect as standard QA/QC included in API/ISO standards do not cover this matter sufficiently. In cases where hard spots are present (e.g. as it has been observed on API 5L X60, X65 grades) this may lead to rapid SSC failures in severe sour service environments. Thus, the European Pipeline Research Group (EPRG)(3) launched at the end of 2017 a research program to define the SSC (Sulfide Stress Cracking) limits of TMCP pipes, to do a literature survey on Non-Destructive Techniques (NDT) able to detect surface hardness anomalies, and finally to reproduce hard layers through a "lab scale TMCP rolling” and point out the potential root cause of surface hardening. The current paper highlights work in progress with a specific focus on SSC limits of both API 5L X52 and X65 grades suitable for sour service and for natural gas applications in compliance with NACE MR0175/ISO 15156 - SSC Region 3 requirements. Threshold stress is determined using NACE TM0316 four-point bend testing in environments ranging from 1 to 17 bar of partial pressure of H2S. Results are discussed with respect to the through wall hardness of materials and recommendations are then proposed to be considered in general for sour service line pipe projects.
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Bange, M. E., A. J. Beaudoin, M. G. Stout, and S. R. MacEwen. "Measurement of the Material State Including the Effects of Recovery and Recrystallization." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1865.
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Abstract Deformation at elevated temperatures in combination with high strain rates leads to recovery and recrystallization in aluminum alloys. Previous work in recrystallization has emphasized the detailing of microstructural trend in progression from the deformed to the annealed state. In the following, we examine the effect of rate dependence on deformation on AA 5182 and AA 6061. It is demonstrated that identification of underlying microstructural mechanisms is critical. An experimental program is then outlined for characterization of recovery and recrystallization of AA 5182. Instantaneous hardening rate and flow stress are developed from interrupted compression tests. These data are used to establish a quantitative measure of recovery through evaluation of a state variable for work hardening, the mechanical threshold. It is intended that the results serve as a foundation for development of relations for evolution of a mechanical state variable in the presence of recrystallization. Such a framework is necessary for the practical prediction of interstand recrystallization in hot rolling operations.
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Al-Aboodi, A., N. Merah, A. R. Shuaib, Y. Al-Nassar, and S. S. Al-Anizi. "FEA of the Effects of Initial Tube-Tubesheet Clearance, Wall Reduction and Material Strain Hardening on Rolled Joint Strength." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93202.
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The tube-to-tubesheet joint strength is measured in terms of residual contact pressure between the tube’s outer surface and tubesheet hole surfaces. The joint integrity is affected by several design parameters, including the type of tube and-tubesheet materials, level of expansion and the initial radial clearance between the tube and tubesheet. In the present work, an axisymmetric finite element model based on the sleeve diameter and rigid roller concepts is developed. The model has been used to evaluate the combined effects of clearance, wall reduction level and the-strain hardening of tube and tubesheet materials on the interfacial pressure between tube and tubesheet. The FE results show that the initial clearance effect is dependent on the strain hardening capability of the tube material. For low strain hardening tube material the interfacial pressure remains almost constant well above the TEMA (Tubular Exchanger Manufacturing Association) maximum radial over tolerance of 0.0254 mm. These results are validated by the experimental data developed during the research program. As expected, a drastic reduction in joint strength is observed at high values of radial clearances. The cut-off clearance (clearance at which the interfacial pressure starts to drop) is found to vary linearly with the level tube material hardening level. The residual pressure is found to increase slightly for moderate strain hardening tube materials but shows lower cut-off clearances. Wall reductions ranging from 1% to 10% were utilized in calculating the contact pressure as a function of radial clearance. The results show that for low strain hardening materials the optimum value of residual contact stress is obtained for the industry recommended value of 5%. Finally, because of the absence plastic deformation in the ligament, the level of tubesheet material strain hardening does not have any noticeable effect to the joint strength.
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Toscano, Rita G., Javier Raffo, Marcelo Fritz, Ronaldo C. Silva, Joshua Hines, and Chris Timms. "Modeling the UOE Pipe Manufacturing Process." In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/omae2008-57605.
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It has been demonstrated in previous work that, for deepwater applications, the cold forming processes involved in UOE pipe manufacturing significantly reduces pipe collapse strength. To improve the understanding of these manufacturing effects, Tenaris has embarked on a program to model the phases of the UOE manufacturing process using finite element analysis simulations. Phase 1 of this work, presented previously in the literature [1], formulated the basis for the model development and described the 2D approach taken to model the various steps of manufacture. This paper presents the results of the Phase 2 work, and includes a description of the enhancements made to the modeling approach, a summary of the full-scale collapse testing performed at C-FER, and a comparison of the model predictions to the test results. Variations are made to the simulated manufacturing process in order to evaluate the sensitivity of collapse strength to key parameters. Based on the modeling approach taken, the findings of the Phase 2 work have shown that the deterioration of the collapse pressure diminishes with increasing O-press compression. The residual stress value is the most sensitive parameter when the strain hardening varies. It increases with the compression ratio and with the strain hardening value. In addition, given the assumed compression ratio of the test pipes, predictive behavior of the test results was found to be acceptable.
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Novak, Jiri. "About Relation Between Irradiation Hardening of Ferritic Steels and Ductile Fracture Toughness Decrease." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77026.
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We showed recently that temperature dependence of the ductile fracture toughness can be predicted on the base of two assumptions: 1) assumption of constant characteristic length, 2) assumption of proportionality between J-R curve slope and deformation work in unit volume, evaluated from zero to critical strain for initiation of deformation bands determined in plane strain geometry for material modeled by deformation theory of plasticity. Temperature dependence of ductile fracture toughness results simply from temperature dependence of the stress-strain curve. Irradiation hardening changes stress-strain behavior in a qualitatively different way: It is observed that irradiation hardening to certain yield stress level changes the stress-strain curve of the material in the same way as prestraining of the unirradiated material to the same flow stress level does. Equivalence of irradiation and prestraining concerns all key properties of deformation theory; namely the secant modulus should be taken from the stress-strain curve of unirradiated material. With exception of this specific feature, the task of finding relative fracture toughness decrease by irradiation is the same as prediction of relative decrease of fracture toughness by temperature change. In the frame of the corresponding theory, relative decrease of ductile fracture toughness expressed by J-R curve slope can be obtained from the stress-strain curve of unirradiated material and irradiation hardening level. Quantitative results are presented for the weld metals 72W and 73W, studied in the Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program, and compared with experimental data.
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Scott, Colin, and Abu Muntakim. "An Analysis of Flow Strength Models for Failure Pressure Prediction of Metal Loss Features in Oil and Gas Pipelines." In 2024 15th International Pipeline Conference. American Society of Mechanical Engineers, 2024. https://doi.org/10.1115/ipc2024-133358.
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Abstract Failure pressure prediction of metal loss features is a vital part of any pipeline integrity management program. Assessments are typically performed using the ASME B31G based models. These models have evolved over the years, from the original to modified B31G models, to effective area / RSTRENG models, to the most recent PSQR model. Some of these methodologies are also included in API 579, BS 7910 and DNV corrosion flaw assessments. Recent work by PRCI has demonstrated these models, although increasingly refined in their approach, maintain a conservative bias in their failure pressure predictions. This decreases efficiency of the owner’s integrity programs. Some analysts have attributed the conservatism to limitations in the flow strength models used in the assessments. This work uses finite element methods to analyze the stress and strain distributions at the bases of long metal loss flaws to better understand plasticity behavior during plastic collapse. A key parameter of interest is the Ramberg-Osgood hardening exponent, which characterizes flow of material during the failure process. Materials with higher or lower hardening exponents show differences in their stress and strain distributions. In effect, there are multiple “shades of grey” between purely elastic and purely plastic behavior. This has a follow-on effect on how flow strength should be defined for different flaw geometries. In some cases, the current flow strengths models are suitable. In other cases, the definition needs refinement. Recognition of these effects can contribute to optimizing current models. The study also looks at currently available failure pressure data, from both in-service and laboratory tests. The trends observed in the flow strength modelling are considered with respect to the true failure strength of metal loss flaws. The results of the study provide insights into limitations of the current flow strength models and suggest possible improvements for improved failure pressure predictions going forward.
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Tran, Minh N., Ondrej Muránsky, Michael R. Hill, and Mitchell D. Olson. "Numerical Analysis of Weld Residual Stress in a Pressurizer Surge Nozzle Full-Scale Mockup: The Effect of Hardening Constitutive Model and Interpass Temperature." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45744.
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In an effort to shed light on accuracy and reliability of finite element (FE) weld modeling outputs, the U.S. Nuclear Regulatory Commission (NRC) and the Electric Power Research Institute (EPRI) have been engaged in a program of cooperative research on weld residual stress (WRS) prediction. The current work presents numerical FE simulation of the WRS in a pressurizer surge nozzle full-scale mockup (Phase 2b), as a part of the broader NRC/EPRI program. Sequentially-coupled, thermo-mechanical FE analysis was performed, whereby the numerical solution from the thermal analysis was used as an input in the mechanical analysis. The thermal analysis made use of a dedicated weld modeling tool to accurately calibrate an ellipsoidal Gaussian volumetric heat source. The subsequent mechanical analysis utilized the isotropic and nonlinear kinematic hardening constitutive models to capture cyclic response of the material upon welding. The modeling results were then validated using a number of measurement techniques (deep hole drilling, contour method, slitting, and biaxial mapping). In addition, an effect of the interpass temperature (i.e. 24.5 °C, 150 °C, and 260 °C) on the final prediction of WRS is discussed.
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Bakirov, Murat, Sergei Chubarov, Igor Frolov, and Joerg Gastrock. "Development of Universal Methodology of Specimen Free Nondestructive Inspection (Control) of Mechanical Properties of NPP Equipment Metal in All Stages of Lifetime." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75606.
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Ever-increasing requirements for reliability and safety of equipment in nuclear power plants (NPP) dictate a necessity to obtain reliable and validated information about the condition of materials in the most safety-relevant and economically vital systems structures and components (SSC). Thus it is a state of science and technology approach to use one method, one methodic and one methodology to facilitate these goals with the purpose of keeping NPPs operating safely by virtue of knowing the state of ageing they are in (with respect to design limits and margins). Method of the control/measurement/testing - how to conduct measurements; methodic - how to interpret the results of measurement; methodology - the program of the control/inspection and testing programmes: localities to conduct the tests, how often, and to follow evolution of test results with the aim of acting before a failure occurs. Such methodology should be based on the use of specimen-free nondestructive method of the inspection (control), which could be used successfully at all stages of life cycle of the equipment: manufacturing, construction, installation of NPP, operation and during the NPP operation through integration into the Plant Life Management (PLiM) programme [1]. It will facilitate a real picture of change (degradation) of a SSC material’s condition in the zones subjected to the harschest stressors (neutron irradiation, erosion-corrosion/flow, thermal fatigue, vibration etc). Currently, there are various approaches used in the world to follow NPP ageing degradation, but until now, no specific methodology is used that could supply all the necessary information [2]. Therefore, there is no way to use various results. Thanks to considerable advances over the last 20 years or so, the science of hardness testing offers an elegant, non-destructive way to obtain vital materials properties — even in-situ on operating SSC [3–6]. In particular, the material’s elastic-plastic condition may be measured, giving indications on tensile yield stress elevation due to hardening and also loss in ductility. The work-hardening index may be easily obtained, giving information on the ability of the material (e.g. pressure vessel steel and weld) to deform plastically without brittle fracture. Taking into account the experience of the Center of Material Science and Lifetime Management Ltd. (CMSLM Ltd.) in the use of methods of hardness testing for the inspection of the equipment of NPP of Russian manufacture in Russia, Germany, Czech, Slovakia, Bulgaria [7], and also similar successful works in this direction in USA (Oakridge) [8], to Czech (NRI Rez) and other countries, it can be seen that the most promising direction in the field of specimen-free inspection of mechanical properties by use of hardness and hardness-related characteristics is use of the kinetic indentation method (KIM, ABIT). This method is based on recording the process of elastoplastic deformation caused by the indentation of a ball indenter. This method allows one to obtain, besides hardness values, tensile properties, elongation, work hardening coefficient, true-stress/true strain diagrammes which normally required the destructive testing of small specimens. However, till now there is no universal method of interpreting the information obtained, although it is generally known that irradiation causes a loss in ductility and increase in hardness and lowering of the work-hardening coefficient. Thus, it is necessary to develop a uniform methodology of using KIM, ABIT with reference to the inspection of materials which will allow to unify the inspection of materials of various classes of the equipment of NPP over all stages of life cycle. With the purpose of introduction of such a methodology it is necessary to develop and realize the program in the frames of IAEA with the above name.
Reports on the topic "Work hardening program"
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Leis, Brian, Xian-Kui Zhu, and Tom McGaughy. PR-185-133739-R01 Quantifying Re-Rounding in Pipeline Damage Severity Models. Pipeline Research Council International, Inc. (PRCI), 2018. http://dx.doi.org/10.55274/r0011479.
Full textAbstract:
The objective of this work was to quantify re-rounding effects on mechanically damaged pipelines. This was done to determine if curvature suffices to identify where the effects of re-rounding are localized. It also was done to establish a framework that could be calibrated through subsequent analysis as an input to guidelines for damage severity assessment. Recognizing the expanding role of ILI and related in-the-ditch evaluation tools to help size and characterize damage, brief consideration was also given to ongoing work within the PRCI Nondestructive Evaluation (NDE) Program. This was done regarding the use of such technologies to assess metallurgical changes in the damaged zone and their integration into model development and sensitivity analysis. Key conclusions for the analysis completed for this project and its validation by comparison to full-scale data include: - Re-rounding can cause significant nonlinear effects in otherwise simple pressure cycling, due in part to localized strain hardening and localized kink formation when it occurs within dents and/or gouges; - Metal-loss due to gouging can be simply idealized without jeopardizing the utility of analysis of the effects of re-rounding, as shown by three validation cases benchmarked against full-scale test-ing; - Re-rounding showed a first-order dependence on pipe geometry and pressure; and - Curvature change appears adequate to quantify re-rounding, but is inadequate to quantify local damage severity in a Level 1 damage screening tool: this also requires consideration of membrane strain (stress) and wall thinning where it is evident. The dependence of re-rounding on pipe geometry and pressure should be broadly quantified, with analyses to trend the role of membrane stress included to build the basis for an ILI-based model to screen damage severity.