Relevant bibliographies by topics / Fatique factor

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Fatique factor'

Author: Grafiati
Published: 4 June 2021
Last updated: 10 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Fatique factor.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Fatique factor"

1

Kanajmi, Humaira', Meizul Zuki, and Damres Uker. "AGE AND WORK EXPERIENCES TO FATIQUE FEELINGS AND WORK PRODUCTIVITY RELATIONSHIP OF PALM OIL FRUIT BUNCH HARVEST WORKERS." Jurnal Agroindustri 7, no. 1 (May 27, 2017): 44–55. http://dx.doi.org/10.31186/j.agroind.7.1.44-55.

Full text
Abstract:
Purpose of this research was to analyze the correlation between the factor of age with fatigue of worker, the factor of working experience with fatigue of worker, the factor of age and working experience with fatigue of worker, and fatigue of workers with work productivity in palm oil harvesting. Data were collectedby using quisionere. The analytical method used in this research is the analysis of correlation and linear regression.From the results of this study concluded that there was a significant, quite strong (r = 0.469) and in the same direction (positive) correlation between the age worker factor with fatigue of palm oil harvester by linear regression equation ????1 = 2,571 + 0,077 X1, there was a significant, but low (r = -0.344) and not in the same direction (negative) correlation between the factor of working experience with fatigue of palm oil harvester by linear regression equation ????1 = 6,303 - 0,067 X2, there was a significant and very strong correlation (R = 0.922) between factors of age and working experience with fatigue of palm oil harvester by linear regression equation ????1 = 0,742 + 0,178 X1 - 0,195 X2, and there was a significant, but low (r = -0.271) and not in the same direction (negative) correlation between the fatigue of workers with productivity of palm oil harvesting by linear regression equation ????2 = 258,45- 6,979 X. Labor of palm oil harvesting should be managed by factor age of workers and work experience in order to minimize fatigue of workers so that can improve productivity.
APA, Harvard, Vancouver, ISO, and other styles
2

Fudenberg, H. H., G. Pizza, C. DeVince, D. Ablashi, and D. Viza. "Antigen-specific transfer factor in chronic fatique immune dysregulation syndrome and viral infections." Clinical Immunology Newsletter 17, no. 6 (June 1997): 91–92. http://dx.doi.org/10.1016/s0197-1859(97)80303-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Ada, Elif Nilay, Nikos Comoutos, S. İlke Bal, and Zekai Pehlivan. "BEDEN EĞİTİMİ DERSİNE YÖNELİK DURUMSAL GÜDÜLENME, TUTUM VE İÇSEL KONUŞMA ARASINDAKİ İLİŞKİ." e-Journal of New World Sciences Academy 15, no. 4 (October 31, 2020): 53–66. http://dx.doi.org/10.12739/nwsa.2020.15.4.2b0127.

Full text
Abstract:
In this study was to determination of the relationship between situational motivation (SIM), self-talk (ST) and attitude towards physical education (PE) lesson and students' other perceptions (liking level of PE-SEV, the level of importance given to the PE by the student-KVO and the level of perception of the importance given to PE by the family-AVO). Furthermore, it has been done the comparisons in terms of age and gender. A total of 698 secondary school students aged between 11-14 in the study. In the findings, girls obtained higher means for all sub scales of SIM and attitude, while boys obtained higher score for worry dimension only of ST. Girls obtained higher scores for SEV and KVO, whereas boys obtained higher means for AVO. When the age increased, SEV, KVO, AVO, instrinsic motivation-IM, identification regulation-IR and attitude decreased but somatic fatique factor of negative ST increased. SEV, KVO and AVO were positive correlated with the positive dimesions whereas negative correlated with the negative dimensions. IM and IR dimensions were found positive correlated with positive ST dimensions and attitude; but extrinsic motivation and amotivation dimensions were found negative correlated with attitude and, positive correlated with negative ST dimensions.
APA, Harvard, Vancouver, ISO, and other styles
4

Duan, Zhihao, Jinliang Xu, Han Ru, and Menghui Li. "Classification of Driving Fatigue in High-Altitude Areas." Sustainability 11, no. 3 (February 4, 2019): 817. http://dx.doi.org/10.3390/su11030817.

Full text
Abstract:
Driving fatigue is one of the main causes of traffic accidents. Thus, to prevent traffic accidents and ensure traffic safety, the properties of driving fatigue at the wheel must be determined. The Qinghai–Tibet Plateau in China is known for its high elevation, causing hypoxia, and presence of severely cold areas; all these easily lead to fatigue during driving. This, in turn, seriously affects the traffic safety on the high-altitude highway. Therefore, the factors leading to driving fatigue and the influence of high-altitude on driving fatigue affecting the driver must be further studied. In this study, we classified and quantified driving fatigue according to the driving fatigue degree. We determined three levels of driving fatigues (i.e., mild, moderate, and severe fatigues) to present their influence on drivers. Our study shows that in this high-altitude area, drivers became fatigued within a significantly shorter time.
APA, Harvard, Vancouver, ISO, and other styles
5

Gao, Yixiang, Maria Dietrich, and Guilherme N. DeSouza. "Classification of Vocal Fatigue Using sEMG: Data Imbalance, Normalization, and the Role of Vocal Fatigue Index Scores." Applied Sciences 11, no. 10 (May 11, 2021): 4335. http://dx.doi.org/10.3390/app11104335.

Full text
Abstract:
Our previous studies demonstrated that it is possible to perform the classification of both simulated pressed and actual vocally fatigued voice productions versus vocally healthy productions through the pattern recognition of sEMG signals obtained from subjects’ anterior neck. In these studies, the commonly accepted Vocal Fatigue Index factor 1 (VFI-1) was used for the ground-truth labeling of normal versus vocally fatigued voice productions. Through recent experiments, other factors with potential effects on classification were also studied, such as sEMG signal normalization, and data imbalance—i.e., the large difference between the number of vocally healthy subjects and of those with vocal fatigue. Therefore, in this paper, we present a much improved classification method derived from an extensive study of the effects of such extrinsic factors on the classification of vocal fatigue. The study was performed on a large number of sEMG signals from 88 vocally healthy and fatigued subjects including student teachers and teachers and it led to important conclusions on how to optimize a machine learning approach for the early detection of vocal fatigue.
APA, Harvard, Vancouver, ISO, and other styles
6

Pan, Long, Jian Chao Pang, Yu Jun Xie, Meng Xiao Zhang, Liang Liang Nie, Yun Xian Mao, and Zhe Feng Zhang. "A fatigue life prediction method from magnetic pole material to simulation part." International Journal of Damage Mechanics 28, no. 9 (March 13, 2019): 1438–54. http://dx.doi.org/10.1177/1056789519835904.

Full text
Abstract:
Due to the higher reliability needs of the large moving component motor-generator rotor, the assessment of the service life has drawn more and more attention. After finite element analysis of the rotor, the simulation part which can represent the magnetic pole with the most dangerous position of the rotor was designed to investigate the S–N curves. Compared with the conventional specimen, considering the main influencing factors of fatigue life for simulation part, the comprehensive factor was proposed to establish the fatigue life relationship between magnetic pole material and simulation part. It was found that the calculation method of fatigue notch factor based on the notch sensitivity factor is relatively simple and practical, and there is no significant effect of surface roughness on high and low cycle fatigues for low roughness ( R a is about 1 µm), and the dimension factor changes linearly with the scale factor. Based on those results, a fatigue life prediction method was proposed and validated, and the predicted results were in good agreement with the experimental data. This study will provide a reasonable reference to determine the fatigue life prediction of large moving components.
APA, Harvard, Vancouver, ISO, and other styles
7

Corwin, Elizabeth J., Laura Cousino Klein, and Kristin Rickelman. "Predictors of Fatigue in Healthy Young Adults: Moderating Effects of Cigarette Smoking and Gender." Biological Research For Nursing 3, no. 4 (April 2002): 222–33. http://dx.doi.org/10.1177/109980040200300407.

Full text
Abstract:
Fatigue is a common complaint of patients seen in primary care. Factors that contribute to fatigue in a patient population include poor health status, psychological stress, poor nutrition, and pregnancy. Less well understood are factors that contribute to fatigue among healthy, nonpregnant individuals. Within the framework of the theory of unpleasant symptoms, 40 healthy young smoking and nonsmoking adults between the ages of 18 and 35 were evaluated to determine self-report level of fatigue and contributing physiological, psychological, and situational factors. Results indicate that while self-report of fatigue did not vary in this population based on gender, subjects who were moderate to heavy cigarette smokers were significantly more fatigued than were nonsmokers (F= 10.24, df = 1, 38, P < 0.01), with the effect being specific to male smokers. Self-report of fatigue did not correlate with body mass index, baseline inflammatory or immune status, or blood pressure. Positive psychological and situational predictors of fatigue included depression (r = 0.556, P < 0.001), state anxiety (r = 0.569, P < 0.001), sleep quality (r = –0.399, P < 0.05), and sleep quantity (r = –0.411, P < 0.05). These results suggest that psychological and situational factors are key contributors to fatigue in young adults and that smoking is a risk factor for fatigue in men.
APA, Harvard, Vancouver, ISO, and other styles
8

Perry, Edward Belk, Sudhanshu Bharat Mulay, Jayesh Kamath, Robert J. Dowsett, Jacob Neuwirth, James Grady, Courtney Gold, Bruce Liang, and Susan Tannenbaum. "Factors influencing fatigue in breast cancer patients undergoing breast irradiation." Journal of Clinical Oncology 33, no. 28_suppl (October 1, 2015): 96. http://dx.doi.org/10.1200/jco.2015.33.28_suppl.96.

Full text
Abstract:
96 Background: We are conducting an exploratory, prospective study to investigate factors associated with radiation-induced fatigue in women with early breast cancer undergoing radiation therapy (RT) for breast conservation. Our hypothesis is that fatigue associated with adjuvant RT is related to tissue damage by apoptosis and inflammation, and to baseline psychological profiles. Methods: All subjects were assessed immediately before RT (T1), mid-point of RT (T2), end of RT (T3), 6 months (T4) and 1 year (T5) after completing RT. Clinical evaluations of skin toxicity, laboratory measures, fatigue, distress, depression, anxiety, sleep, energy and pain were assessed using validated measures. Results: Thirty-one subjects (target 50) have been enrolled to date; 23 have completed T3 and are presented here. 35% had a history of depression and 17% are currently depressed; 22% had past and current anxiety. BCTOS breast pain, tenderness and sensitivity increased during RT and were consistent with functional pain scores. No clinically relevant changes in energy or distress were seen. Despite a notable prevalence of depression and anxiety at baseline, there were no relevant changes in depression or anxiety. Most IL-1β, IL-4, IL-6 and IL-10 levels were undetectable. 39% of subjects showed increases in fatigue and were 14 years younger than non-fatigued subjects. Fatigued subjects had more frequent past (44%) and current (33%) depression than non-fatigued subjects (29% and 7%, respectively), and woke up tired more frequently (44% versus 0%). Current depression, but not fatigue, was associated with decreased a.m. cortisol levels during RT. 56% of fatigued subjects had an RTOG Acute Skin Toxicity score > 1 and 78% had BCTOS breast-specific pain subscales scores ≥ 3 during RT vs. 21% and 14% of non-fatigued subjects, respectively. Serum caspase-1 (inflammation) and caspase-3 (apoptosis), hs-CRP and TNF-α were increased but not associated with fatigue. Conclusions: Our preliminary findings suggest that radiation-associated fatigue is complex and, as hypothesized, is dependent on a patient’s psychological profile in the setting of skin toxicity and insomnia. If this data holds at study completion, it may guide clinical interventions.
APA, Harvard, Vancouver, ISO, and other styles
9

Asprusten, Tarjei Tørre, Maria Pedersen, Eva Skovlund, and Vegard Bruun Wyller. "EBV-requisitioning physicians’ guess on fatigue state 6 months after acute EBV infection." BMJ Paediatrics Open 3, no. 1 (February 2019): e000390. http://dx.doi.org/10.1136/bmjpo-2018-000390.

Full text
Abstract:
We assessed referring medical practitioner’s ability to predict chronic fatigue development in adolescents presenting with acute infectious mononucleosis. Compared with ‘not fatigued’ being predicted as ‘unsurely fatigued’ and ‘likely fatigued’ were both strongly associated with developing fatigue 6 months later (OR 2.5, 95% CI 1.16% to 5.47% and 3.2, 95% CI 1.19% to 8.61%, respectively, P=0.012). The positive and negative predictive values were 66% and 62%, respectively. Disentangling the physician’s intuition may be of interest in further investigations of risk factors and prophylactic factors for fatigue development.
APA, Harvard, Vancouver, ISO, and other styles
10

Nap-van der Vlist, Merel M., Geertje W. Dalmeijer, Martha A. Grootenhuis, Kors van der Ent, Marry M. van den Heuvel-Eibrink, Joost F. Swart, Elise M. van de Putte, and Sanne L. Nijhof. "Fatigue among children with a chronic disease: a cross-sectional study." BMJ Paediatrics Open 5, no. 1 (February 2021): e000958. http://dx.doi.org/10.1136/bmjpo-2020-000958.

Full text
Abstract:
ObjectiveTo determine: (1) which biological/lifestyle, psychological and/or social factors are associated with fatigue among children with a chronic disease and (2) how much each of these factors contributes to explaining variance in fatigue.Design and settingThis was a cross-sectional study across two children’s hospitals.PatientsWe included children aged 8–18 years who visited the outpatient clinic with cystic fibrosis, an autoimmune disease or postcancer treatment.Main outcome measuresFatigue was assessed using the PedsQL Multidimensional Fatigue Scale. Generic biological/lifestyle, psychological and social factors were assessed using clinical assessment tools and questionnaires. Multiple linear regression analyses were used to test the associations between these factors and fatigue. Finally, a multivariable regression model was used to determine which factor(s) have the strongest effect on fatigue.ResultsA total of 434 out of 902 children were included (48% participation rate), with a median age of 14.5 years; 42% were male. Among these 434 children, 21.8% were severely fatigued. Together, all biopsychosocial factors explained 74.6% of the variance in fatigue. More fatigue was uniquely associated with poorer physical functioning, more depressive symptoms, more pressure at school, poorer social functioning and older age.ConclusionsFatigue among children with a chronic disease is multidimensional. Multiple generic biological/lifestyle, psychological and social factors were strongly associated with fatigue, explaining 58.4%; 65.8% and 50.0% of the variance in fatigue, respectively. Altogether, almost three-quarters of the variance in fatigue was explained by this biopsychosocial model. Thus, when assessing and treating fatigue, a transdiagnostic approach is preferred, taking into account biological, psychological and social factors.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Fatique factor"

1

Havlíková, Marie. "Diagnostika systémů s lidským operátorem." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-233473.

Full text
Abstract:
The doctoral thesis is thematically focused to human operator systems significantly contributing to this system reliability and safety. The theoretical part of the thesis is concerned with human activities and communications in MMS system, valuation and estimation of human reliability probability in MSS. The important part of the thesis is also a description of human operator neuromuscular system as an executive powerful system on MMS system regulating activities and the summary of human driver models in compensative lateral car control. The practical part of the doctoral thesis is based on analyses created by experimental data of drives. Experimental drives were done on drivers set following different backgrounds and different sleep deprivation at whole day. All experimental data was realized from the cooperation and following the agreement of Faculty of Transportation Science research centre on Prague ČVUT. Another part of thesis includes driver simulation model proposals with nonlinear components for lateral car control. Simulation model drives are compared with real drives or drivers on drive-simulator and there are monitored identical and different dynamic movement characteristics. The main target of doctoral thesis is to detect and obtain significant dynamical drive experience characteristics based on experimental data analyses. As well to found drive characters variability owing to driver’s fatigue and determinated evaluated characteristics changes. Acquired results of thesis should help in assistant systems that in cooperation with other components alert to micro-sleep and run off drive possibility.
APA, Harvard, Vancouver, ISO, and other styles
2

Doheney, Shaun W. "Sleep logistics as a force multiplier : an analysis of reported fatigue factors from Southwest Asia warfighters /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Sept%5FDoheney.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kweon, Young-Gak. "Influence de divers paramètres sur la fissuration par fatigue d'aciers de construction dans l'eau de mer sous protection cathodique." Châtenay-Malabry, Ecole centrale de Paris, 1986. http://www.theses.fr/1986ECAP0010.

Full text
Abstract:
Etude du comportement en fissuration par fatigue dans l'eau de mer sous protection cathodique des aciers destinés à la construction de structures off-shore (acier E355, acier non allié 0,06%C, acier allié 1%AL1%CR0,06%C, acier allié 0,43%CU0,06%C). Influence des divers paramètres agissant sur la fatigue-corrosion sous polarisation cathodique: paramètres électrochimiques (marnage, potentiel de polarisation cathodique, circulation et ph de la solution), paramètres mécaniques (cyclage, surcharge), paramètres métallurgiques (composition chimique de l'acier, soudage)
APA, Harvard, Vancouver, ISO, and other styles
4

Güngör, Güven. "Biaxial Load Effects on Fatigue Properties." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19079/.

Full text
Abstract:
This study aims to aid many issues related to fatigue, namely biaxial loading, the definition of the finite geometry correction factor of the stress intensity factor and the understanding of the energy dissipation per fatigue crack growth. In our work, we are using the geometry correction factor definition that uses the ratio of external work introduced to the material. Using different biaxiality ratios varies the external work done, thus makes it possible for us to observe how the geometry correction factor handles this variation. The trend of strain energy release rate per crack growth is also investigated through biaxiality. Moreover, the common discussion of the effects of biaxiality on fatigue properties is aided with yet another study. For this purpose, cruciform shaped plate specimen from an aluminum alloy are manufactured and biaxially loaded. Crack growth is observed while load-to-displacement data is recorded to evaluate the external work done on the specimen. As a result, it is seen that biaxiality delays the fatigue failure. Crack growth rates decreases as the biaxiality increases for a given effective stress intensity factor. Making use of the work values for the calculation of the finite geometry correction factor handles the effects of biaxiality well. Strain energy release rate increases as the crack propagates, but there is no trend between strain energy release rate and biaxiality of the loading. In the future works, observing also the crack tip plasticity and trying out a wider range of biaxiality ratios with different types of material would result in more generalizable conclusions. Moreover, more repetitions of the fatigue tests would give more accurate values for the amount work introduced to the material with changing biaxiality.
APA, Harvard, Vancouver, ISO, and other styles
5

Ciomber, Isabelle, and Roland Jakel. "Systematic Analysis and Comparison of Stress Minimizing Notch Shapes : Obtaining a stress concentration factor of Kt=1 without FEM-Code." Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-141533.

Full text
Abstract:
Als Stand der Technik sind einfache, kreisförmige Verrundungen zur Reduktion von Kerbspannungen an Querschnittsübergängen bekannt, für die aus Tabellenwerken / Diagrammen in der Literatur die Formzahl einfach abgelesen werden kann. Die Effizienz der Spannungsreduktion solcher Lösungen ist jedoch sehr begrenzt. Ziel der Arbeit ist es daher, dem Konstrukteur bzw. Berechnungsingenieur ein Verfahren in die Hand zu geben, mit dem er für Standardquerschnittsübergänge und Standardlastfälle "Nicht-Kreiskerben" ohne teure und zeitaufwendige FEM-Analyse einfach durch Nutzung geeigneter Formzahldiagramme auslegen kann. Dabei sind sogar Formzahlen von nahezu eins möglich, d.h., in der "Kerbe" bleibt praktisch nur noch die Nennspannung übrig. Die Präsentation ist zweitgeteilt: Im ersten Teil werden die Arbeitsmethoden bzw. Softwarefunktionen und verwendeten Softwarewerkzeuge vorgestellt: Dies sind die Programme Creo Parametric als vollparametrisches CAD-Werkzeug und Creo Simulate als p-FEM-Programm der Parametric Technology Coprporation (PTC). Der zweite Teil der Präsentation beschreibt den Gültigkeitsbereich sowie die untersuchten Kerbgeometrien: Die einfache kreisförmige Verrundung als Stand der Technik, die Zwei-Radien-Kerbe, die Baud-Kurve, die Methode der Zugdreiecke nach Claus Mattheck, die elliptische Kerbe sowie die konische Rundung als generalisierte elliptische Kerbe. Es wird kurz eine Bibliothek vorgestellt, mit der solche Kerben einfach ausgelegt werden können, d.h. Ihre exakte Geometrie festgelegt sowie die zugehörige Formzahl αk bestimmt werden kann
Circular (one-radius) fillets are known as state-of-the-art for reducing notch stresses at cross section transitions. The stress concentration factor Kt of such geometries can be read out from diagrams/tables given in the literature. However, the efficiency of stress reduction of circular notches is very limited. The goal of the work therefor is to present a method for the designer/analyst how to design non-circular notches/fillets just by using suitable Kt-diagrams without time-consuming and expensive FEM analyses. Kt-numbers of nearly one are possible, that means in the "notch" just the nominal stress appears and no stress concentration takes place. The presentation has two parts: Part one describes the working methods and software functions as well as software tools: Creo Parametric as fully-parametric CAD program and Creo Simulate as embedded p-FEM-tool from Parametric Technology Corporation (PTC) have been used. The second part describes the range of validity and the examined notch geometries: The one-radius fillet as state-of-the-art, the two-radii filet, the Baud-curve, the method of tensile triangles from Claus Mattheck, the standard elliptical fillet and the conical round as generalized elliptical fillet. A notch layout library is shortly presented that allows to design such fillets, that means exactly determine the notch geometry and the related stress concentration factor Kt
APA, Harvard, Vancouver, ISO, and other styles
6

Musinski, William D. "Novel methods for microstructure-sensitive probabilistic fatigue notch factor." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34704.

Full text
Abstract:
An extensive review of probabilistic techniques in fatigue analysis indicates that there is a need for new microstructure-sensitive methods in describing the effects of notches on the fatigue life reduction in cyclically loaded components. Of special interest are notched components made from polycrystalline nickel-base superalloys, which are used for high temperature applications in aircraft gas turbine engine disks. Microstructure-sensitive computational crystal plasticity is combined with novel probabilistic techniques to determine the probability of failure of notched components based on the distribution of slip within the notch root region and small crack initiation processes. The key microstructure features of two Ni-base superalloys, a fine and coarse grain IN100, are reviewed and the method in which these alloys are computationally modeled is presented. Next, the geometric model of the notched specimens and method of finite element polycrystalline reconstruction is demonstrated. Shear-based fatigue indicator parameters are used to characterize the shear-based, mode I formation and propagation of fatigue cracks. Finally, two different probabilistic approaches are described in this work including a grain-scale approach, which describes the probability of forming a crack on the order of grain size, and a transition crack length approach, which describes the probability of forming and propagating a crack to the transition crack length. These approaches are used to construct cumulative distribution functions for the probability of failure as a function of various notch root sizes and strain load amplitudes.
APA, Harvard, Vancouver, ISO, and other styles
7

Weitzel, Thomas R. "Fatigue : investigation of a human factor for aviation curricula." Doctoral diss., University of Central Florida, 1997. http://digital.library.ucf.edu/cdm/ref/collection/RTD/id/20654.

Full text
Abstract:
University of Central Florida College of Education Thesis
This descriptive study investigated the perceived problem of human fatigue as an operational consideration within the U.S. air carrier industry and the status of fatigue as content within U.S. aviation education/training curricula. An instrument was developed and expert-validated for self-completion by the following three groups (each with its sample size): (a) aviation higher education, represented by a mailing to 50 individuals; (b) air carrier training/management, represented by a mailing to 50 individuals; and (c) a professional training group of 58 general aviation flight instructors, with administration by the researcher during scheduled company meetings. The resultant SPSS data set consisted of 116 cases. Eight demographic variables were reported and analyzed with the analysis of variance; and the definition of fatigue, a multiple choice item, was tested for the chi-square goodness-of-fit distribution. The remaining 21 variables were subjected to a factor analysis, utilizing principal-azis fatoring for extraction; orthogonal rotation, which forced the derived factors to be uncorrelated; and varimax, a variance maximizing procedure. The resultant 8 factors removed the duplication from the 21 correlated variables and, when scored, became variables within the SPSS data set. The normalized factor scores were subjected to analysis of variance and post hoc comparison for any significance of difference between the three groups; minor group differences were found for three of the eight factors. The data supported the literature review with respect to human fatigue being perceived as an operational consideration on the flightdecks of U.S. air carriers. The data and the literature also indicated that fatigue is present as content within U.S. aviation curricula. However, the answers to beth research questions involved a matter of degree. Additionally, the data indicated that not all students within U.S. aviation have exposure to fatigue content within their curricula. Teaching the concepts and management of fatigue to some of these student may be as important as (more important than) fatigue as curricular content for flight crews. Future research in the development of a curriculum paradigm for human fatigue in U.S. aviation might utilize the eight factors derived as constructs by the factor analysis utilized in this study.
Ed.D.;
Educational Services;
Education;
133 p.
ix, 133 leaves, bound : ill. ; 28 cm.
APA, Harvard, Vancouver, ISO, and other styles
8

Robinson, Teresa Michelle. "Predictive Factors of Compassion Fatigue Among Firefighters." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2332.

Full text
Abstract:
Few existing studies have examined compassion fatigue among emergency responders even though firefighters and emergency medical service (EMS) professionals have repetitive direct exposure to traumatic events. This study focused on identifying predictor variables for the development of compassion fatigue in firefighters. Karasek's demand-control model, a commonly used work stress model, was the study's theoretical framework as it focuses on specific construct interactions that predict employee well-being. Accordingly, this correlational study examined the predictive nature of EMS license level, years of service, and personality type on the development of compassion fatigue in career firefighters. Data collection occurred with surveys incorporating the Professional Quality of Life Scale and the Big Five Inventory. Mid-Michigan fire departments participated with 129 career firefighters returning completed surveys with results analyzed using logistic regression. Findings revealed a significant predictive relationship between personality traits and the development of compassion fatigue. These findings can inform preventative measures that protect the psychological well-being of these emergency responders by informing and educating the professionals and organizations as to who is at greatest risk and ultimately providing opportunity for risk mediation.
APA, Harvard, Vancouver, ISO, and other styles
9

Pannemaecker, Alix de. "Etude du phénomène d'arrêt de propagation des fissures au travers d'un couplage multi-échelles fretting, fretting fatigue et essai fatigue C(T)." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0010/document.

Full text
Abstract:
De nombreuses structures aéronautiques telles que les contacts aube/disque, rivet/tôle, assemblages frettés ou boulonnés subissent des endommagements de fretting fatigue dus à des sollicitations vibratoires. Ces sollicitations, qui combinent des chargements de contact de fretting (micro déplacements alternés) et de fatigue, peuvent induire des phénomènes de fissuration. L’objectif de cette thèse est d’identifier les mécanismes de propagation et d’arrêt de fissuration pour différentes configurations, impliquant des chargements de fretting et de fatigue. Différents aspects seront étudiés : - Les essais de fretting simple, fretting fatigue et fatigue seront corrélés de manière à mesurer certaines propriétés mécaniques de matériaux. Dans cette démarche, une méthode inverse permettant l’identification du seuil d’arrêt de propagation des fissures longues et courtes en fatigue à partir d’essais de fretting simple et fretting fatigue est introduite. - L’effet du rapport de charge est pris en compte afin de quantifier la fermeture de fissure pour les essais de fretting et fretting fatigue. Un nouveau modèle de fermeture sera proposé. - L’effet d’échelle est étudié grâce au développement d’une nouvelle machine de fretting fatigue permettant le suivi in situ des propagations de fissures sur des éprouvettes millimétriques. Le comportement des fissures courtes en fretting pendant un essai de fretting fatigue a été observé pour la première fois. L’idée principale de ce travail est de considérer que lors d’un essai en fretting simple, une condition d’arrêt de propagation est systématiquement atteinte. Les facteurs d’intensités de contraintes seuils en fatigue peuvent ainsi être extraits par une méthode inverse à partir des essais de fretting. La méthodologie adoptée consiste à mesurer la longueur de fissure maximale obtenue lors d’un essai de fretting correspondant à une condition d’arrêt de propagation. En jouant sur les chargements de fretting, les domaine des fissures courtes et longues sont étudiés. Pour chaque condition d’arrêt, le facteur d’intensité de contraintes seuil correspondant est calculé. Enfin, en traçant l’évolution de ce dernier en fonction de la longueur de fissure, une description complète des seuils d’arrêt de fissuration en fatigue peut être obtenue. Cette méthodologie est appliquée sur plusieurs configurations de fretting simple et est étendue aux essais de fretting fatigue. Ainsi une large gamme de rapports de charge peut être étudiée. Des essais conventionnels de fatigue propagation sur éprouvettes C(T) ont été réalisés de manière à valider complètement la démarche d’identification inverse des conditions d’arrêt de fissuration. Le manuscrit est divisé en six chapitres adoptant une évolution linéaire. Le chapitre 1 traite d’une revue bibliographique concernant la propagation des fissures courtes et longues en fatigue dans les matériaux métalliques, introduisant les phénomènes de fermeture. L’analyse est étendue à la propagation des fissures en fretting et fretting fatigue. Le chapitre 2 présente l’ensemble des techniques et méthodes expérimentales utilisées au cours de ce travail. Une analyse numérique et la méthode inverse d’identification des conditions d’arrêt de propagation sont introduites dans le chapitre 3. Les chapitres suivants traitent les différents résultats obtenus. Le chapitre 4 présente les essais de fretting simples menés sur différents matériaux métalliques. Une corrélation entre les conditions d’arrêt de fretting simple avec celles de fissures longues en fatigue est obtenue pour rapports de charge négatifs. Cette analyse est étendue aux rapports de charge positifs au chapitre 5 en couplant les essais de fretting simple, fretting précontraints et essais de fatigue C(T). Enfin, les effets d’échelle et la cinétique de propagation des fissures de fretting fatigue sont étudiés au chapitre 6
Aircraft structures such as blade/disk, rivet/sheet and fretted or bolted assembly contacts are subjected to fatigue fretting damage caused by vibratory loads. These loads combining fretting (alternating micro displacements) and fatigue contact loading can induce cracks. The objective of this thesis is to identify the propagation and crack arrest mechanisms for different configurations involving fretting and fatigue loads. Various aspects will be studied : - Simple fretting, fatigue fretting and fatigue tests will be correlated in a way to measure some material mechanical properties. A reverse approach allowing to identify the long and short fatigue crack propagation thresholds from simple fretting and fretting fatigue will be introduced. - A new closure model taking into account the effect of loading ratio on crack closure in fretting and fretting fatigue tests will be proposed. - The scaling effect will be studied thanks to the development of a new fretting fatigue machine allowing for in-situ monitoring of the propagation of small scale cracks. The behavior of fretting short cracks has been observed for the first time in a fretting fatigue test. The main idea behind the current work is the consideration that for a simple fretting test, the crack will always lead to a crack propagation arrest condition. Threshold stress intensity factors can thus be extracted from fretting tests using a reverse method. The methodology used consists in measuring the longest fretting crack corresponding to a crack propagation arrest condition. Short and long crack regimes are studied by varying fretting loads and geometries. The corresponding threshold stress intensity factor is calculated for each arrest condition. A complete description of fatigue crack arrest thresholds can be obtained from a plot depicting the evolution of the stress intensity factor range as a function of crack length. This methodology has been applied on multiple simple fretting configurations and was extended to fretting fatigue tests allowing to study a large range of loading ratios. Conventional fatigue crack propagation tests were carried out on C(T) specimens in order to validate the reverse method used for crack arrest conditions. The present thesis is divided into six main chapters. Chapter 1 provides a complete literature review on short and long crack propagation in metallic materials introducing crack closure. It provides a treatment for both fretting and fretting fatigue including a comparative analysis. Chapter 2 provides an overview of the different techniques and methodologies used as part of this research project. The reverse method used for the identification of crack propagation arrest conditions as well as a numerical analysis are presented in Chapter 3. The following Chapters provide a treatment of the various results obtained. Chapter 4 focuses on simple fretting tests carried out on different metallic materials. A correlation between simple fretting and long fatigue crack arrest conditions was obtained for negative loading ratios. This analysis is extended to positive loading ratios in Chapter 5 combining simple fretting, prestressed fretting and C(T) fatigue tests. Finally, scaling effects and fretting fatigue crack propagation kinetics are studied in Chapter 6
APA, Harvard, Vancouver, ISO, and other styles
10

Lozano, Minguez Estivaliz. "Fatigue and fracture mechanics of offshore wind turbine support structures." Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9756.

Full text
Abstract:
Wind power, especially offshore, is considered to be one of the most promising sources of ‘clean’ energy towards meeting the EU targets for 2020 and 2050. However, its popularity has always fluctuated with the price of fossil fuels since nowadays wind electricity production cannot compete with nuclear or coal electricity production. Support structures are thought to be one of the main drivers for reducing costs in order to make the wind industry more economically efficient. Foundations and towers should be fit for purpose, extending their effective service life but avoiding costs of oversizing. An exhaustive review of the background and state of the art of the Fatigue-Life assessment approaches has been carried out, combining analysis of the gathered experimental data and the development of Finite Element models based on contemporary 3D solid models with diverse Regression Analyses, in order to identify their weakness and evaluate their accuracy. This research shows that the guides and practices currently employed in the design and during the operation of the offshore wind turbine support structures are obsolete and not useful for optimisation, which generally leads to conservationism and an unnecessary increase in costs. The basis for a comprehensive update of the Girth Weld and Tubular Joint S-N curves and the Stress Concentration Factors of Tubular Joints has been set out. Furthermore, a reliable methodology for deriving the Stress Intensity Factor at the deepest point of a semi-elliptical surface saddle crack in a tubular welded T-joint has been proposed.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Fatique factor"

1

Kirshenbaum, Mira. The emotional energy factor: The secrets high-energy people use to beat emotional fatigue. New York: Bantam Dell, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Fundamentals of aircraft material factors. Los Angeles, Calif: Safety Dept., Institute of Safety and Systems Management, University of Southern California, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Pagani, Catherine Mary. Fatigue is in the eye of the beholder: Using human factors data to relieve visual fatigue in the museum visitor. [Toronto: University of Toronto], 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Alfred, Buch. Improvement of fatigue life prediction accuracy for various realistic loading spectra by use of correction factors. Haifa, Israel: Technion-Israel Institute of Technology, Dept. of Aeronautical Engineering, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Naik, Rajiv A. Determination of stress intensity factors for interface cracks under mixed-mode loading. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Kirsten, Kite, ed. Flight stress: Stress, fatigue, and performance in aviation. Aldershot, Hants, England: Avebury Aviation, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Stokes, Alan. Flight stress: Stress, fatigue and performance in aviation. Aldershot: Ashgate, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Shipping, Lloyd's Registerof. Complex tubular joints: Assessment of stress concentration factors for fatigue analysis. London: HMSO, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Nykänen, Timo. Mk-factor equations and crack growth simulations for fatigue of fillet-welded t-joints. Lappeenranta: Lappeenranta University of Technology, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

National Research Council (U.S.). Committee on the Effects of Commuting on Pilot Fatigue. Issues in commuting and pilot fatigue: Interim report. Washington, D.C: National Academies Press, 2011.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Fatique factor"

1

Gooch, Jan W. "Fatigue Notch Factor." In Encyclopedic Dictionary of Polymers, 296. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_4794.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Seedhouse, Erik, Anthony Brickhouse, Kimberly Szathmary, and E. David Williams. "Fatigue." In Human Factors in Air Transport, 23–47. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13848-6_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wessely, Simon. "Viruses and Fatigue." In Psychiatry and Biological Factors, 231–56. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4684-5811-4_22.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Gdoutos, E. E. "Dynamic Stress Intensity Factor." In Problems of Fracture Mechanics and Fatigue, 359–63. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_78.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Radaj, Dieter. "Extended Stress Intensity Factor Concepts." In Advanced Methods of Fatigue Assessment, 101–265. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-30740-9_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Preumont, André. "Peak Factor and Random Fatigue." In Twelve Lectures on Structural Dynamics, 201–15. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-6383-8_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Rodopoulos, C. A. "Safety Factor and Residual Strength." In Problems of Fracture Mechanics and Fatigue, 501–3. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_109.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Ebermann, Hans-Joachim, and Maria-Pascaline Murtha. "Fatigue and Alertness Management." In Human Factors on the Flight Deck, 187–209. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31733-0_8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Rodopoulos, C. A. "Safety Factor and Fatigue Life Estimates." In Problems of Fracture Mechanics and Fatigue, 491–94. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_106.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Rodopoulos, C. A. "Safety Factor of a Disk Sander." In Problems of Fracture Mechanics and Fatigue, 519–26. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2774-7_112.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Fatique factor"

1

Mathews, Gemi Maria, and Althaf M. "Review on Factors Governing Stress Concentration Factor at Tubular Joints." In International Web Conference in Civil Engineering for a Sustainable Planet. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.112.31.

Full text
Abstract:
Tubular structures have become so much in use because of their structural performance and attractive appearance. But at the intersections of these tubular structures (i.e., tubular joints), there is stress concentration which adds the fatigue damage in structures which is exposed to cyclic loads. The stress concentration factor plays a crucial role in the computation of fatigue life of tubular structures exposed to cyclic loads. This paper aims to review the factors governing stress concentration factor at tubular joints.
APA, Harvard, Vancouver, ISO, and other styles
2

Stahl, B., and H. Banon. "Fatigue Safety Factors for Deepwater Risers." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28405.

Full text
Abstract:
Fatigue life is governed by a number of variables that are highly uncertain. The safety factor on fatigue life is used in a deterministic way to account for the estimated fatigue damage uncertainty. High uncertainties lead to high fatigue safety factors, and vice versa. Evaluation of the uncertainties in the variables governing fatigue design provides a grip on what the safety factor should be. This paper addresses riser fatigue using a fatigue reliability model that is relatively simple but still captures the important elements of the fatigue problem. The bias and uncertainty of stress range are extremely important parameters in design against fatigue. This is due not only to the fact that these parameters are highly uncertain, but also to the fact that they are greatly amplified in the fatigue damage equation by the ‘slope’ m of the S-N curve. The Palmgren-Miner fatigue damage index and the intercept value of the S-N curve are additional important variables in fatigue design. A model for combining wave-induced and vortex-induced vibration (VIV) is introduced together with the best available data and reference to industry work in this technology area. A recently completed joint industry project on riser reliability provides good calibration points for the critical fatigue reliability variables. Reliability and sensitivity studies are performed to demonstrate the effect of the uncertainty parameters. An approach to selecting deterministic fatigue design factors that yield specified reliability targets is developed and illustrated. The study provides a rational approach to selecting safety factors for design of deepwater risers, taking into account both wave and VIV-induced fatigue damage.
APA, Harvard, Vancouver, ISO, and other styles
3

de Haan - de Wilde, F. H. E., F. J. Blom, and M. H. C. Hannink. "Quantitative Comparison of Environmental Fatigue Methods." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45027.

Full text
Abstract:
For many nuclear power plants worldwide the operation period will be extended from 40 to 60 years in the coming years. As the operation period increases the importance of knowledge of ageing mechanisms like fatigue increases. Knowledge of the influence of the environment is crucial, since environmental fatigue is a relatively new development which is a modification to the existing assessment method and has to be projected to 60 years as well. This paper is a follow up of the ASME PVP2013-97695 paper: overview of international implementation of environmental fatigue. A quantitative comparison of the resulting cumulative usage factors including environmental fatigue is made for the most commonly used and well defined methods. The comparison of the environmental fatigue codes is made on a spray nozzle of the pressurizer. This is a known fatigue relevant location with high stresses due to thermal loading. The high thermal loading is due to the spraying of relative cold water into the warm pressurizer. The comparison is made for 11 methods, sets of fatigue curves and environmental fatigue correction factors (Fen factor), and 4 types of material. The 4 materials are: low alloy, carbon, nickel alloy and austenitic stainless steel. The fatigue curves of ASME 2007, ASME 2010, KTA 1996, KTA 2013, NUREG/CR-6909 and Code Case N-792 are compared. The Fen factors are compared for the following methods: NUREG/CR-6583, NUREG/CR-5704, NUREG/CR-6909, Code Case N-792, JNES SS-0503, JNES SS-1005 and NUREG/CR-6909 rev1. Code Case N-761 is included for the final comparison of the cumulative usage factors including environmental fatigue. The differences in percentages are considerable between the different methods. For this specific case, the difference in cumulative usage factor including environmental fatigue for austenitic steels is 70 %. For nickel alloy materials the difference is 115%. For low alloy materials the difference is the highest: 267%. For carbon steels the difference in cumulative usage factor is 146%. The most conservative cumulative usage factors including environmental fatigue are ASME 2007 or KTA 1996 fatigue curves combined with the NUREG/CR-5704 (austenitic steel and nickel alloy) or NUREG/CR-6583 (low alloy and carbon steel). The next highest results are found by the Japanese methods (JNES-SS-0503 and JNES-SS-1005). The common factor for these methods, is the fatigue curve for austenitic steels as used before 2010. The lowest cumulative usage factors are obtained by implementing NUREG/CR-6909. Using the latest revision of NUREG/CR-6909 the cumulative usage factors increase slightly (about 7%). The paper shows the considerable differences of usage factors when different codes are applied to the same problem.
APA, Harvard, Vancouver, ISO, and other styles
4

Kucharski, Paweł, Grzegorz Lesiuk, Tomasz Czapliński, Roman Fratczak, and Łukasz Maciejewski. "Numerical estimation of stress intenisty factors and crack propagation in lug connector with existing flaw." In FATIGUE FAILURE AND FRACTURE MECHANICS XXVI: Proceedings of the XXVI Polish National Conference on Fatigue Failure and Fracture Mechanics. Author(s), 2016. http://dx.doi.org/10.1063/1.4965949.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Humelnicu, Costel. "FATIGUE POLYMERIC MATERIALS - AIR POLLUTION FACTOR." In 19th SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings. STEF92 Technology, 2019. http://dx.doi.org/10.5593/sgem2019v/4.2/s06.030.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Woods, Kirby, and Kenneth Thomas. "Instrument Nozzles Fatigue Strength Reduction Factor." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97472.

Full text
Abstract:
Recent industry experience has raised concerns with the NRC regarding the fracture toughness of small partial penetration instrument nozzles. Historically, small-bore instruments have not been evaluated when Pressure-Temperature curves were developed. Typical instrument nozzles have an outside diameter of 3¼ inches or less and a wall thickness of 11/16 inches or less. They were considered to be exempt per ASME XI Appendix G-2223(c), “Fracture toughness analysis to demonstrate protection against non-ductile failure is not required for portions of nozzles and appurtenances having a thickness of 2.5 in. (63 mm) or less, provided the lowest service temperature is not lower than RTNDT plus 60°F (33°C).” Now it appears that the effect of the nozzle discontinuity on the stresses in the beltline region of the shell must be assessed. This paper will show that historical interpretation of the code is correct and a fatigue analysis of the vessel shell adjacent to these instrument nozzles is unnecessary. The industry experience with instrument nozzle leakages is typically related to the quality of manufacturing as suggested by J.H. Gross. Fabrication and inspection range quality relative to FSRF is ke = 10 for poor and ke < 5 for good quality. This approach appears to correlate well with this consideration and industry experience. This paper will also demonstrate the use of fabrication travelers and/or inspection information that can be used to determine an appropriate FSRF to assess the relative health of these and other components.
APA, Harvard, Vancouver, ISO, and other styles
7

Vargas, Pedro M., Ben Crowder, Weiwei Yu, Sam Mishael, and Keith Armstrong. "Full Scale Sour Fatigue Testing With Dense Phase Gases." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83898.

Full text
Abstract:
The petrochemical industry is very interested in the sour service fatigue performance of girth welded steel pipes. As a result several papers are published every year addressing this issue, and several Joint Industry Projects (JIP) are currently underway addressing different aspects of sour service performance of steel pipelines. To date research work has focused on quantifying the fatigue performance via small scale specimens due to the difficult and danger in dealing with H2S. Currently a JIP is underway that promises to provide full scale fatigue performance of pipeline welds under sour service. This paper documents the knockdown-factor-on-life (KD) determination for full scale sour service testing. In an industry first, a very difficult full scale sour service test was performed: 1) High Pressure, 2) High content of H2S, 3) Dense phase gases with ultra low water content (less than 400 ppm), and 4) Loading rate of 0.01 Hz. The loading was applied in full longitudinal tension. The full scale sour tests are compared with full scale in-air tests to obtain the knockdown factor. Resource constraint limited the number of full scale tests to 3. The main objective of the tests for the practical application was to ensure that the usage of crack growth based knock-down factors, i.e. the use of Fatigue-Crack-Growth-Acceleration-Factor (FCGAR) from small scale fracture mechanics specimens, was reasonable and conservative. Some additional comparisons are done with crack-growth based knockdown factors that may help explain the effect of the ultra-low water concentration. Knockdown factors from small scale crack growth specimens, Fatigue-Crack-Growth-Acceleration-Factor = 60 (FCGAR), are significantly higher than the full scale results, KD = 7. The ultra-low-water dense phase gases do not pit the surface, thus leaving the initiation life relatively intact. The knockdown factor for the full scale test is then mostly the result of the accelerated crack growth that occurs once a macro-crack nucleates.
APA, Harvard, Vancouver, ISO, and other styles
8

Emslie, Julian, Chris Watson, and Keith Wright. "ASME III Fatigue Assessment Plasticity Correction Factors for Austenitic Stainless Steels." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28633.

Full text
Abstract:
ASME III NB-3200 provides a method for carrying out fatigue calculations using a simplified elastic-plastic analysis procedure. This allows a correction to elastic analysis to be performed in place of a full elastic-plastic analysis. Two mutually exclusive factors are described: the Poisson’s ratio correction accounts for surface stress exceeding the yield strength of the material and the Ke factor accounts for gross section plasticity. The recently released ASME Code Case N-779 provides a more complex but less onerous calculation of the Ke factor. Correction factors from the JSME and RCC-M codes have also been considered in this paper. The conservatism of different plasticity correction factors has been examined by calculating a ratio between the equivalent strain range from elastic-plastic Finite Element (FE) models and the strain range from elastic FE models and comparing this to calculated plasticity correction factors. Results show the potential for both the current ASME and Code Case Ke corrections to under-predict the strains when compared to those from an elastic-plastic FE assessment. A preliminary investigation has been carried out into an alternative correction factor based on linearised stress and local thermal stress ranges. This addresses the discontinuity between the two correction methods for surface and sectional plasticity which has been identified as a feature of the ASME correction methodology.
APA, Harvard, Vancouver, ISO, and other styles
9

Hoh, Hsin Jen, John H. L. Pang, and Kin Shun Tsang. "Fatigue Modelling of Semi-Elliptical Surface Cracks in Welded Pipe Geometries." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54683.

Full text
Abstract:
Offshore pipelines and risers transfer oil and gas across long distances, from seabed to production facility to the surface. The long pipelines are formed by welding together pipe segments. The welded joints formed are a source of stress concentration and defects from which fatigue cracks can grow. Hence, it is imperative that the effect of the weld geometry on the stress concentration be understood so that appropriate measures can be taken to assess the potential remaining service life of the welded structure. The effects can be understood by the linear elastic fracture mechanics approach, where the stress intensity factors quantify the stress concentration. While the classical equations of Newman and Raju have been long available for semi-elliptical surface cracks in plates, no similarly elegant stress intensity factor solutions are available for pipes. There have been solutions in tabular form which can be cumbersome in practice. Moreover, solutions of welded pipe geometries have not been developed. The objectives of the current work are to develop closed-form solutions for stress intensity factors for external semi-elliptical surface cracks in plates. The welded pipe geometry will also be studied to develop solutions for the weld toe magnification factors of welded pipe geometries. The stress intensity factors can be used to determine the propagation rate of cracks in pipe or welded pipe geometries. The stress intensity factors are obtained by the J-integral output of the three-dimensional finite element method. First, a plate with a circular crack is modelled. The initial step transforms the model to a plate with a semi-elliptical crack with the appropriate crack aspect ratio and width. A second transformation follows to transform the geometry to pipe form. The main parameters studied are the relative crack depth to thickness, crack aspect ratio, radius and thickness. The developed stress intensity factor solutions can be reduced to the classical equations. The new solutions show good agreement compared to previous work. A similar approach is developed to study the welded pipe geometry to develop weld toe magnification factor solutions. The weld toe magnification factor solutions for certain geometries are presented as a function of the relative crack depth. The stress intensity factor solutions are then applied to predict the crack growth rates of cracks in pipe geometries. The prediction was conducted by a program written to assess the fatigue life of single and multiple cracks in pipes and welded pipes. The fatigue life assessment of welded pipes using the weld toe magnification factor solutions shows how significantly the weld geometry affects fatigue life.
APA, Harvard, Vancouver, ISO, and other styles
10

Miura, Naoki, Masaki Nagai, and Masaki Shiratori. "Study on Evaluation Accuracy Required for Stress Intensity Factor Solution." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97563.

Full text
Abstract:
Stress intensity factor solutions are often used as a dominant fracture mechanics parameter for fatigue crack growth analysis. In ASME Boiler and Pressure Vessel Code Section XI as well as JSME Rules on Fitness-for-Service for Nuclear Power Plants, fatigue crack growth is predicted on the basis of the stress intensity factor range. Stress intensity factor solutions are frequently provided by the correction factors, which are tabulated as the functions of structure and/or crack sizes. In this study, the effect of the variation of the correction factors on the crack growth analysis results was investigated for pipes with surface cracks. The evaluation accuracy required for the correction factors of the stress intensity factor solutions was then examined and recommended from the comparison with the necessary accuracy of the parameters used for the fatigue crack growth analysis.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Fatique factor"

1

Skochko, G. W., and T. P. Herrmann. Factors which affect fatigue strength of fasteners. Office of Scientific and Technical Information (OSTI), November 1992. http://dx.doi.org/10.2172/10173808.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Lankford, James. Study of the Effects of Metallurgical Factors on the Growth of Fatigue Microcracks. Fort Belvoir, VA: Defense Technical Information Center, November 1987. http://dx.doi.org/10.21236/ada188475.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kimmel, Donald B. Factors in Risk Prediction and Healing of Stress Fractures and Fatigue Damage in the Female Skeleton. Fort Belvoir, VA: Defense Technical Information Center, November 1998. http://dx.doi.org/10.21236/ada364081.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

LI, Zijing, Yufeng YU, Huan DENG, Yimin ZHANG, Si CHEN, Jinlian YU YU, and Jing LI. Incidence and influencing factors of chronic fatigue syndrome in nurses: A protocol for meta-analysis and systematic review. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, January 2021. http://dx.doi.org/10.37766/inplasy2021.1.0011.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Fitzgerald, Robert, Kenneth J. Stalder, Neal Matthews, Collette Schultz-Kaster, and Anna K. Johnson. Effect of Environmental Factors on the Frequency of Fatigued Pigs and Mortality Rates at a Commercial Abattoir. Ames (Iowa): Iowa State University, January 2008. http://dx.doi.org/10.31274/ans_air-180814-849.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Mohanty, Subhasish M., Bryan J. Jagielo, William I. Iverson, Chi Bum Bhan, William S. Soppet, Saurin M. Majumdar, and Ken N. Natesan. Online stress corrosion crack and fatigue usages factor monitoring and prognostics in light water reactor components: Probabilistic modeling, system identification and data fusion based big data analytics approach. Office of Scientific and Technical Information (OSTI), December 2014. http://dx.doi.org/10.2172/1168230.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Bao, Jieyi, Xiaoqiang Hu, Cheng Peng, Yi Jiang, Shuo Li, and Tommy Nantung. Truck Traffic and Load Spectra of Indiana Roadways for the Mechanistic-Empirical Pavement Design Guide. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317227.

Full text
Abstract:
The Mechanistic-Empirical Pavement Design Guide (MEPDG) has been employed for pavement design by the Indiana Department of Transportation (INDOT) since 2009 and has generated efficient pavement designs with a lower cost. It has been demonstrated that the success of MEPDG implementation depends largely on a high level of accuracy associated with the information supplied as design inputs. Vehicular traffic loading is one of the key factors that may cause not only pavement structural failures, such as fatigue cracking and rutting, but also functional surface distresses, including friction and smoothness. In particular, truck load spectra play a critical role in all aspects of the pavement structure design. Inaccurate traffic information will yield an incorrect estimate of pavement thickness, which can either make the pavement fail prematurely in the case of under-designed thickness or increase construction cost in the case of over-designed thickness. The primary objective of this study was to update the traffic design input module, and thus to improve the current INDOT pavement design procedures. Efforts were made to reclassify truck traffic categories to accurately account for the specific axle load spectra on two-lane roads with low truck traffic and interstate routes with very high truck traffic. The traffic input module was updated with the most recent data to better reflect the axle load spectra for pavement design. Vehicle platoons were analyzed to better understand the truck traffic characteristics. The unclassified vehicles by traffic recording devices were examined and analyzed to identify possible causes of the inaccurate data collection. Bus traffic in the Indiana urban areas was investigated to provide additional information for highway engineers with respect to city streets as well as highway sections passing through urban areas. New equivalent single axle load (ESAL) values were determined based on the updated traffic data. In addition, a truck traffic data repository and visualization model and a TABLEAU interactive visualization dashboard model were developed for easy access, view, storage, and analysis of MEPDG related traffic data.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Fatique factor' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography