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Sångelevers motivation : - Hur kan övningslusten upprätthållas? / Vocalist Students' Motivation : – How can the desire to practise be maintained?Lindqvist, Per Fredrik January 2018 (has links)
Syftet med denna studie är att förstå hur sångelever och sångpedagoger vid svenska gymnasieskolans estetiska program förhåller sig till motivation som drivkraft i övning och undervisning och hur sedan denna kunskap nyttjas i arbetet i sångkurserna. Totalt har sex elever och en sångpedagog deltagit i undersökningen som genomförts i form av kvalitativa intervjuer. Resultatet av studien visar att kunskapsnivån om hur övningslusten kan upprätthållas är god men borde kunna höjas genom medvetandegörande av hur motivation fungerar både hos undervisande pedagoger och hos studenter då det finns mycket olika forskning i ämnet som refererats till i detta arbete. De känner till, men bör till viss del kunna höja den mer djupgående förståelsen för och kunskapen om begreppet motivation och de olika teorier som finns med didaktiska implementeringsmöjligheter i ämnet. Undersökningen har lett till djupare insikt om och förståelse för det komplexa samspel lärare elev emellan för att nyttja och vårda motivationen i undervisningen. Analys av resultatet visar att varje elev kräver en ny analys av läraren för att finna det optimala arbetssättet för att uppnå den optimala motivationen hos eleven då olika elever kräver olika arbetssätt. / The purpose of this study is to understand how vocalist students and vocalist teachers at the Swedish Upper Secondary School’s Aesthetic Program relate to motivation as a driving force in teaching and in practice and how this knowledge is used in the courses’ daily voice and song teaching. Six students and one song teacher have participated in the study which was done with qualitative interviews. The result of the study shows that the level of knowledge about how the desire to practice can be maintained is good. However this knowledge should be able to be improved on by increasing awareness of how motivation works with both teachers as well as students. There is a lot of research being done on the subject which is referred to in this study. Both teachers and students have the knowledge but should, to a certain degree, be able to raise the level of a deeper understanding of, and knowledge of the concept, and different theories of motivation as well as the usage of it, and further possibilities of didactic implementation. The study has led to a better insight and understanding of the complex interaction between teacher and student in using and caring for motivation in the teaching/learning situation. The analyses of the results have shown that each student demands a new analyses from the teacher to find the optimal way of teaching to reach the optimal motivation in the student as different students need different ways of learning.
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Att ha kul, meningsfullhet och inställning främjar grit hos barnWeiss, Petra, Ilmavirta, Päivi January 2018 (has links)
Livsstilsvanor och personliga egenskaper som till exempel grit grundas under barndomen och påverkar hälsan i vuxenlivet. I en värld där ohälsan bland barn ökar är det viktigt att undersöka individers beteenden för att sedan kunna använda dessa kunskaper i ett hälsopromotivt arbete. Syftet med studien var att beskriva och utveckla kunskap av barns medvetenhet och erfarenheter av grit i ett hälsofrämjande perspektiv. Datainsamlingen gjordes via Grit-S enkäten och fokusgrupper där totalt 19 barn i åldrarna 9-11 deltog. Det insamlade materialet analyserades med latent kvalitativ innehållsanalys. Analysen resulterade i ett huvudtema; Att ha kul, meningsfullhet och inställning främjar grit. Analysen resulterade även i fyra underteman; “Att ha kul leder till långvarigt intresse”, “meningsfullhet och målsättning styr ansträngning”, “det finns alltid en väg förbi motgångar om man försöker” och “grit är inte hugget i sten förutsatt att du kan se framåt”. Resultatet visar på att ha kul är den viktigaste förutsättningen för att barn skall utveckla ett långvarigt intresse. När intresset finns sätter barnen upp mer tydliga och långsiktiga mål. De måste kunna föreställa sig framtiden och förstå vart deras handlingar och insatser kan leda för att de skall se en mening till att utföra dem. I skolan ser barnen inte vart deras insatser leder. De flesta barn anser att hantering av motgångar kan ske på flera sätt samt att förmågan att hantera dem kan utvecklas med åldern. Slutsatsen tyder på att skolan och fritidsaktiviteter är bra arenor för att utveckla egenskapen grit genom hälsofrämjande interventioner. / Lifestyle habits and personal characteristics such as grit are founded during childhood and affect health in adulthood. In a world where children's health is decreasing it is important to investigate the behavior of individuals to be able to use this knowledge in work with health promotion. The aim was to describe and develop an understanding of children's awareness and experiences of grit in a health promotion perspective. Data was collected using the Grit-S survey and focus groups where a total of 19 children between ages 9-11 participated. The collected data was analyzed with latent qualitative content analysis. One main theme was identified; Having fun, meaningfulness and attitude promote grit. The following four subthemes also emerged: “Having fun leads to long-term interest”, “meaningfulness and goal setting regulate effort”, “there is always a way beyond setbacks if you try” and “grit is not set in stone as long as you can look forward”. The result shows that having fun is the most important factor for children to develop a long-term interest. When there is interest, the children set clearer and more long-term goals. They must be able to imagine the future and understand what their actions and efforts can lead to so they can see a purpose to fulfill them. At school, the children do not see clearly where their efforts lead. Most children believe that dealing with setbacks can be handled in several different ways, and that the ability to handle them can develop with age. The conclusion suggests that school and leisure activities are good venues to develop grit through health promotion interventions.
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VAD SOM ÄN KRÄVS! : En studie om drivkrafter hos blivande operatörer.Andersson, Daniel, Södergren, Pierre January 2021 (has links)
För att hantera den förändrade situationen i närområdet måste Försvarsmakten öka sin operativa förmåga och med det, även sin rekrytering. För specialförbanden har utebliven värnplikt inneburit en reducerad rekryteringsbas samtidigt som Försvarsmakten, för att öka sin operativa förmåga, bl.a. skapat förband med specifika kompetenser, förmågor och uppgifter vilket i sin tur lett till en konkurrenssituation avseende bemanning. För specialförbanden har detta tillsammans med ett lågt utfall från uttagningstesterna inneburit en utmaning att tillgodose det operativa behovet av systemets viktigaste resurs, personalen. Denna kvalitativa studie som baseras på semistrukturerade intervjuer och en workshop syftar till att, utifrån operativ personal vid specialförbanden, fördjupa förståelsen för hur utfallet av uttagningstesterna skall kunna förbättras. Studiens identifierade drivkrafter, som ligger till grund för individer att söka till samt fullfölja de fysiskt och psykiskt krävande uttagningstesterna, analyseras därför gentemot motivationsteorier, organisatoriska perspektiv och psykologiska begrepp. Studien tyder på att även om drivkrafterna för att söka till respektive fullfölja testerna skiljer sig åt, så bidrar dessa tillsammans med stödjande funktioner till individens förmåga att härda ut, vilken är avgörande för att fullfölja uttagningstesterna. Utifrån resultatet kan specialförbandens attraktion utformas och riktas på ett tydligare sätt. Vidare kan befintliga urvalskriterier vidareutvecklas för att ur det totala antalet sökande, kunna kalla de individer med bäst förutsättningar att lyckas fullfölja och klara uttagningsprocessen. / The Swedish Armed Forces needs to increase the recruitment rate and operational capability in order to handle the developing situation in the region. For the Special Forces, the lack of conscripts has meant a reduced recruitment at the same time as the rest of the Armed Forces, in order to increase operational capability, has created units with specific skills, abilities and tasks, which in turn have led to a competitive situation regarding the staff. This together with a high attrition rate from selection process has led to a challenge meeting the operational demand regarding the Special Forces most valuable asset, the personnel. This qualitative research, based on semi-structured interviews and a workshop with operational personnel at the Special Forces aims to increase the understanding of how the outcome of the selection process can be improved. The driving factors identified in this research, which form the basis for individuals to apply to the Special Forces and complete the physically and psychologically demanding selection tests, are hence analysed in relation to motivational theories, organizational perspectives and psychological terms. The study indicates that the drive for applying to and completing the selection differ, however, both of them combined with supportive functions contribute to the individual's ability to persevere and are crucial elements for completing the selection process. Based on the results attraction of the Special Forces can be designed and directed more accurately. Furthermore, existing selection criteria can be refined in order to, out of the total number of applicants, be able to select the individuals with the best chance to successfully complete the selection process.
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Varför väljer fastighetsmäklare att byta bransch? : - En studie om vilka faktorer som påverkar svenska fastighetsmäklares avsikt att byta branschSjögren, Anna, Öhman, Emma January 2021 (has links)
Titel: Varför väljer fastighetsmäklare att byta bransch?Nivå: Examensarbete på Grundnivå (kandidatexamen) i ämnet företagsekonomi Författare: Anna Sjögren och Emma ÖhmanHandledare: Dr. Jonas Kågström och biträdande Martin AhleniusDatum: 2021 - juni Syfte: Syftet med denna studie är att undersöka hur motivationsfaktorerna yttre motivation, inre motivation, Grit – passion och uthållighet för långsiktiga mål, och relationsbyggande påverkar svenska fastighetsmäklares jobbtillfredsställelse och avsikt att byta bransch. Metod: Denna studies metod är av kvantitativ karaktär med ett deduktivt synsätt, där datan har insamlats med hjälp av en webbaserad enkät. Enkäten har skickats ut till urvalet, bestående av 4497 stycken svenska fastighetsmäklare, av hela populationen på 7110 stycken fastighetsmäklare. Totalt resulterade enkäten i 932 svar, där 910 av dessa kunde användas. För att analysera datan har statistikprogrammen Jamovi och Smart PLS använts. För att kunna redovisa och tolka resultatet har deskriptiva analyser gjorts, bivariata korrelationsanalyser, faktoranalyser samt strukturella ekvationsmodelleringar. Resultat & slutsats: Undersökningen visar på aggregerad nivå att Grit i hög grad påverkar den inre motivationen och att inre motivation är den faktor som har störst betydelse för en fastighetsmäklares upplevda jobbtillfredsställelse. Jobbtillfredsställelse i sin tur är den faktor som påverkar deras avsikt att byta bransch mest. Men, undersökningen visar även att jobbtillfredsställelse påverkar den yttre motivationen och att yttre motivation påverkar avsikten att byta bransch. Dessutom påverkas jobbtillfredsställelsen av faktorn relationsbyggande. Dessa motivationsfaktorers betydelse varierar dock beroende på olika demografiska variabler. Utifrån resultatet och hypotesprövningen, togs en egen modell fram, som benämns ”REAMF-modellen”. Examensarbetets bidrag: Denna studie bidrar med kunskap om vilka motivationsfaktorer som påverkar svenska fastighetsmäklares avsikt att byta bransch. Denna studies resultat är också användbart i praktiken för ledare inom branschen. Genom att som ledare veta vilka motivationsfaktorer som motiverar de enskilda anställda fastighetsmäklarna, kan passande motivationsstrategier framtas för just dessa, för att öka deras upplevda jobbtillfredsställelse, för att därmed minska deras avsikt att byta bransch. Förslag till fortsatt forskning: Denna studies motivationsfaktorer förklarar ca 40% av varför svenska fastighetsmäklare har för avsikt att byta bransch. Det hade varit intressant att undersöka fler motivationsfaktorer som kan påverka detta val. En replikering av denna studie, i något annat land, efterfrågas också till vidare forskning. Slutligen vore det intressant att se om REAMF-modellen är applicerbar på andra yrken. / Title: Why do real estate agents choose to leave the industry?Level: Student thesis, final assignment for Bachelor Degree in Business Administration Authors: Anna Sjögren and Emma ÖhmanSupervisors: Dr. Jonas Kågström and assistant Martin AhleniusDate: 2021 - June Aim: The purpose of this study is to examine how the motivational factors extrinsic motivation, intrinsic motivation, Grit – passion and perseverance for long-term goals, and relationship building affect Swedish real estate agents' job satisfaction and turnover intention. Method: This study is based on a quantitative research method with a deductive approach, where the data has been collected using a web-based survey. The survey was sent to the sample, consisting of 4497 Swedish real estate agents, of the entire population of 7110 real estate agents. The survey resulted in 932 respondents, of which 910 could be used. To analyze the data, the statistical programs Jamovi and Smart PLS have been used. To interpret the study’s results, descriptive analyzes have been performed, bivariate correlation analyzes, factor analyzes and structural equation modeling. Result & Conclusions: The result of this study shows at an aggregate level that Grit highly influences the intrinsic motivation and that intrinsic motivation is the factor that mostly affects the perceived job satisfaction. Job satisfaction in turn is the factor that affects turnover intention the most. But, the result also shows that job satisfaction affects extrinsic motivation, and that extrinsic motivation affects turnover intention. In addition, job satisfaction is affected by the factor relationship building. However, the significance of these motivational factors varies depending on different demographic variables. Based on the results and the hypothesis test, a separate model was developed, which is called the “REAMF model”. Contribution of the thesis: This study contributes to knowledge about which motivational factors that affect Swedish real estate agents' turnover intention. The results of this study are also useful in practice for the employers. By knowing which motivational factors that motivate the individual real estate agents, appropriate motivational strategies can be developed to increase their perceived job satisfaction, and accordingly decrease their turnover intention. Suggestions for future research: This study's motivational factors explain about 40% of Swedish real estate agents turnover intention. Further research is suggested to examine other motivational factors that may affect turnover intention. A replication of this study, in another country, is also requested for further research. Finally, it would be interesting to see if the REAMF-model is applicable in other industries.
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The Relationship of Motivated Strategies for Learning, Mental Toughness, and Grit to Developmental Math Student Success in an Adaptive Learning Technology EnvironmentVanderheiden Guney, Stacey Lynn 08 1900 (has links)
The importance of the study is grounded in the need to increase the success rates at community colleges, which is critical for meeting national goals for college attainment and promoting upward social mobility. The majority of community college students arrive unprepared for college-level math and are placed into developmental math. A drive to increase math performance has focused on course redesigns incorporating adaptive learning technologies. While adept at adapting subject matter to students' individual needs, there remains the need to understand the role of student metacognition in the learning process. The purpose of this study is to investigate the association between specific learner attributes and academic success in developmental math for students who are acquiring their skills through an adaptive learning technology environment. The Motivated Strategies of Learning Questionnaire, GRIT, and Mental Toughness Questionnaires were used to uncover relationships and differences between measured traits, student success, and demographic items such as age, gender, race, amount of time spent in paid work, and previous credits. Survey results were analyzed using a correlation research design and demonstrated significant relationships between time and gender, topics mastered and race, time and Motivated Strategies for Learning, time and self-regulation, and grade and emotional control. The study makes recommendations about how to best develop and leverage adaptive learning technologies in the future.
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Impact of Grit on Performance After Mastery- or Performance-Oriented FeedbackAuerbach, Alex 05 1900 (has links)
Grit and achievement motivation have been predictors of behavior in academia and military settings (Duckworth, Matthews, Peterson, & Kelly, 2007), but to date, research on their effects on sport performance has been limited. Given grit's predictive role in other performance domains, grit may be influential in athletes' long-term goal attainment, interacting with their achievement motives and leading to better performances. Athletes' trait levels of grit may influence how they understand and respond to messages received within motivational climates from key personnel such as from coaches and teammates. We examined potential moderating effects of grit on the relationship between motivational feedback and high school soccer players (N = 71, Mage = 15.81) performance on a soccer task, their desire to persist in the task, and their choices of task difficulty. We used hierarchical multiple regression to test the main effects of feedback and grit and to determine if grit moderated the effects of feedback on performance. Grit was a significant moderator of the feedback-shooting performance relationship, accounting for 3.9% of variance. Simple slopes analysis revealed a significant effect for low (B = 13.32, SEb = 4.44, p = .004, t = 2.99), but not high, (B = 2.11, SEb = 4.31, p = .63, t = .49), grit on task success. Grit was not a significant moderator of task difficulty selection or task persistence. These results suggest that for those high in grit, feedback about natural ability or hard work is not particularly influential on performance. However, for low grit athletes, type of feedback matters.
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Dopady politiky rozvoje venkova na regionální produkci, příjmy a zaměstnanost v kraji Vysočina / Rural development policy impacts on regional output, income and employment in Vysocina RegionBednaříková, Zuzana January 2007 (has links)
This dissertation follows the increasing extent of the European Union's intervention into rural areas. The main objective of the dissertation is to analyse and evaluate the impacts of measures supporting job creation, within the Rural Development Programme of the Czech Republic for 2007--2013, on regional production, income and employment in the Vysočina region. Specifically, it concerns the measures under Axis 3 Pillar 2 of the EU Common Agricultural Policy supporting diversification into non-agricultural activities, micro-businesses and tourism development. The sub-objective is to analyse the coefficients and multipliers, which would identify the sectors with the greatest potential for further development in terms of production, income and employment in the Vysočina region. Within the main objective three alternatives impacts that arise when there is a change of the final demand for production of a given industry are analysed and these can be measured by changes in production, income or employment. Two formulated hypotheses are analysed in detail In the individual chapters the dissertation is focused on the theoretical aspects of rural development dealing with the aspects of rural development policy implementation, describing the models and empirical analysis of the impact of measures supporting rural economic development. It also describes the characteristics of the Vysočina region, offering a methodology and construction of a regional input-output table and the input-output model for the Vysočina region, and finally, it includes a methodology and application of the impact analysis for the region. In order to achieve the main objective Leontief's structural input-output analysis is used (Leontief, 1966). The regional short-term macroeconomic input-output model built on the example of the Vysočina region serves as a tool for the analysis. A part of the analysis is the identification of factors that influence the size of the impact found. To perform the impact analysis the author constructed a regional input-output table for the Vysočina region. The regionalization of the national commodity symmetric input-output table (CZSO, 2010f) is performed using the GRIT method (Jensen et al., 1979). The selected method is suitable for assessing the short-term impact of political measures, where the found effects can be attributed exclusively to the political measures observed. All the restrictions typical of input-output analysis have been taken into account. The scientific contribution of the dissertation is the creation of a regional macroeconomic input-output model for the Vysočina region based on Leontief's input - output analysis, and its use to determine the impact of the realised funds on the monitored measures of production, income and employment in the Vysočina region. The other scientific contribution is the construction of a regional input-output table for the Vysočina region. This serves as a data source for the input-output analysis since regional input-output tables are not available in the Czech Republic.
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The Relation of Perceived Motivational Climate, Mindset, and Achievement Goal Orientation to Grit in Male High School Soccer PlayersAlbert, Erin D. 12 1900 (has links)
Grit is defined as "perseverance and passion for long-term goals." Although studied in relation to various outcomes, such as retention and academic performance, few studies have examined variables that may contribute to grit's development. Further, few studies have examined this construct in relation to sport performance or within athletic environments, despite its clear connection to sport-related constructs like mental toughness and resilience. Thus, based in achievement motivation theory, this study examined the relations of the perceived motivational climate as defined by athletes' perceptions of the coaches' behaviors (task vs. ego), athletes' perceptions of their achievement goal orientation (task vs. ego), athletes' perceptions of their implicit theory (i.e., fundamental beliefs regarding whether or not ability can change; growth vs. fixed), and athletes' perception of their level of grit. Male varsity soccer players (N = 81; Mage = 15.80 ± .81) from a large metropolitan area in the south central U.S. completed questionnaires measuring these achievement motivation constructs. The full regression model was significant, accounting for 18% of the grit variance, F(6, 74) = 2.77, p = .017. Within the full model, having a growth mindset (β = .25, p = .035) and endorsing a task goal orientation (β = .36, p = .004) predicted higher levels of grit for the athletes. Neither the coach-created motivational climate, nor the athletes' ego orientation or fixed mindset, were significantly predicted their grit scores. Consistent with Dweck and Duckworth, components of achievement motivation theory, particularly related to a task or growth perspective, may play an important role in athletes' developing a perspective that allows them to work effectively and diligently toward long-term goals.
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THE SHORT GRIT SCALE: A DIMENSIONALITY ANALYSISLi, Caihong 01 January 2015 (has links)
This study aimed to examine the internal structure, score reliability, scoring, and interpretation of the Short Grit Scale (Grit-S; Duckworth & Quinn, 2009) using a sample of engineering students (N = 610) from one large southeastern university located in the United States. Confirmatory factor analysis was used to compare four competing theoretical models: (a) a unidimensional model, (b) a two-factor model, (c) a second-order model, and (d) a bi-factor model. Given that researchers have used Grit-S as a single factor, a unidimensional model was examined. Two-factor and second-order models were considered based upon the work done by Duckworth, Peterson, Matthew, and Kelly (2007), and Duckworth and Quinn (2009). Finally, Reise, Morizot, and Hays (2007) have suggested a bi-factor model be considered when dealing with multidimensional scales given its ability to aid researches about the dimensionality and scoring of instruments consisting of heterogeneous item content. Findings from this study show that Grit-S was best represented by a bi-factor solution. Results indicate that the general grit factor possesses satisfactory score reliability and information, however, the results are not entirely clear or supportive of subscale scoring for either consistency of effort subscale or interest. The implications of these findings and future research are discussed.
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Approche thermomécanique de l’interface meule/pièce/lubrifiant lors de la rectification de dentures d'engrenage en acier nitruré : impacts sur l’intégrité du matériau rectifié / Thermomechanical approach of the interface wheel/workpiece/lubricant during a nitride steel gear grinding : impacts on the grinded material integrityLavisse, Bruno 19 October 2017 (has links)
La rectification est un procédé de fabrication permettant d’obtenir des états de surface avec une rugosité très faible. Elle est généralement utilisée sur des matériaux très durs pour lesquels les autres procédés d’usinage ne sont pas adaptés, cependant, ce procédé fait intervenir des mécanismes d’enlèvement matière complexes et difficiles à mettre en oeuvre. Lors du processus de rectification, l'énergie de rectification est principalement convertie en chaleur entre la pièce, la meule, le liquide d'arrosage et les copeaux. Les températures et les flux de chaleur à l'interface meule/pièce dépendent de la géométrie du contact, du matériau rectifié, de la meule (taille de grains, géométrie, densité, porosité, usure), de son dressage, des paramètres de rectification (profondeurs de passe, vitesse d'avance, vitesse de meule, conditions de dressage), des conditions d'arrosage et de lubrification. Les températures élevées peuvent engendrer des transformations métallurgiques superficielles, des gradients de contraintes résiduelles, ainsi que des variations dimensionnelles notables. D’une façon générale l’intégrité de surface peut être grandement modifiée par cette interaction. Les conditions de rectification doivent garantir les critères de qualité et d'intégrité du matériau tout en répondant aux besoins d’augmentation de la productivité en milieu industriel. L'objectif cette thèse a été l'étude mécanico-thermique de l'interface meule/pièce/lubrifiant, dans le but de réduire le risque d'endommagement lors de la rectification d’une denture d’engrenage en acier nitruré et de qualifier les transformations éventuelles impactant l’intégrité de la pièce qui lui est associé. Pour cela nous avons développé plusieurs axes de recherche. Nous avons proposé et vérifié expérimentalement à partir d’une méthode inverse et de mesures de température par thermocouple rectifiable, un modèle de flux thermique permettant, en utilisant une mesure d’effort de prédire le profil de température à l’interface meule/pièce/lubrifiant. Nous avons effectué un comparatif détaillé de meules dans le but de déterminer celle qui permettra pour un état de surface donné de limiter le risque d’endommagement thermique du matériau rectifié. Pour effectuer cette étude, nous nous sommes intéressés à la profondeur de passe maximale admissible de chaque meule avant brûlure. Ce comparatif a été mené à la fois en laboratoire et en milieu industriel. Nous avons ensuite étudié l’influence des endommagements thermiques provoqués par la rectification en étudiant et en qualifiant la microstructure de l’acier nitruré. L’utilisation de moyens de mesure classiques (dureté, MEB EBSD, DRX) ou inédits et peu utilisés sur les brûlures de rectification (bruit Barkhausen, spectroscopie Raman) nous a permis de définir les modifications du matériau endommagé en termes de contraintes résiduelles, de dureté, de tailles de grain et de création d’oxydes. Enfin, nous avons mené une étude détaillée sur l’influence de la lubrification lors de la rectification de notre acier nitruré. Nous avons pour cela modifié indépendamment les débits et vitesses d’arrosage en sortie de buse et observé les changements que cela engendrait sur le profil température dans la zone de rectification et sur le coefficient de répartition de la pièce / The grinding process is very useful to obtain a very precise surface finish. It is generally used on very hard materials which cannot be machined by other conventional machining processes. However grinding involves very complex material removal mechanisms and most of the time is difficult to set up. During the grinding process, the main grinding energy is converted into heat between chip, lubricant, wheel and workpiece. Temperature and heat flux in the grinding zone depend on the contact geometry, on the material, on the wheel (grit size, geometry, porosity, wear), on the dressing, on the grinding parameters (depth of cut, workpiece speed, wheel speed) and on lubrication conditions. High temperatures result in thermal damage such as metallurgical changes, stress gradients, and changes in workpiece dimensions. In general terms, because of this process, surface integrity may be seriously damaged. Grinding parameters have to guarantee the workpiece quality and have to respond to the productivity improvement in machining and cutting industry. The target of this thesis was the mechanical and thermal study of the grinding zone between workpiece, wheel and lubricant in order to reduce the burn risk during the grinding of a nitrided steel gear. The purpose was also to define possible transformations associated to this damage. To achieve it, we developed several research topics. We proposed an experimentally verified heat flux model, usable to predict accurately the nitrided steel temperature in the lubricated grinding zone. This model is based on an inverse method and temperature measurements with a workpiece/foil thermocouple. We made a grinding wheel comparative study in order to determine the wheel capable, for a given workpiece roughness, of limiting the risk of burn. To perform this study, we focused, for each wheel, on the maximum allowable depth of cut before burning. This comparative study was led both in laboratory and industrial conditions. We also studied the influence of thermal damages in grinding by studying and qualifying the nitrided steel microstructure. The use of classical measurement techniques such as: hardness, SEM, EBSD and DRX or original and underused techniques such as Barkhausen noise or Raman spectroscopy permitted to define changes in the burned grinded materials. Between the two states of materials (burned and no burned), we observed differences in hardness, grain size and ferrous oxides creation. At last, we made a detailed study on the lubrication efficiency during grinding of the nitrided steel. For this purpose we changed independently fluid flow and jet speed in outlet nozzle. Then we observed the modifications this could cause on the temperature distribution in the grinding zone and on the workpiece heat partition ratio
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