• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 13
  • 13
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The investigation of wire rope defect using contactless dynamic method / Plieninių lynų defektų tyrimas taikant bekontaktį dinaminį metodą

Šutinys, Ernestas 29 January 2014 (has links)
The dissertation investigates the diagnostics of wire rope by using forced characteristics. The main object of research is defects of prestressed ropes using a dynamic systems characteristic. The primary purpose of this dissertation is to research the characteristics of a prestressed rope with outside of broken wire and to create research methodology of broken wires and determine its location. The paper approaches a few major tasks such as by experiment detecting the dynamic characteristics of the wire rope and detection broken wire on the surface of the wire rope using dynamic characteristics. Task 1 is formulated as the literature review found that the wire rope defects detected by using of the dynamic characteristics received little attention. Task 2 relates to the first problem solution, as measured by vibrating amplitude of broken wire, it is important to assess the reliability of measuring instruments. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the paper, research methodology, scientific novelty, the practical significance of results examined in the paper and defended statements. The introduction ends in presenting the author’s publications on the subject of the defended dissertation, offering the material of made presentations in conferences and defining the structure of the dissertation. Chapter 1 analysis used literature. It contains a wire rope defects and diagnostic... [to full text] / Disertacijoje nagrinėjama plieninių lynų defektų nustatymas taikant jėgines charakteristikas. Pagrindinis tyrimo objektas yra įtemptų plieninių lynų defektų nustatymas naudojant lyno, kaip dinaminės sistemos, savybes. Pagrindinis disertacijos tikslas – ištirti įtempto plieninio lyno su išoriniame sluoksnyje nutrūkusiomis vielomis savybes ir sukurti nutrūkusių vielų bei jų vietos nustatymo tyrimų metodiką. Darbe sprendžiami keli pagrindiniai uždaviniai: eksperimentiškai nustatytos plieninio lyno dinaminės charakteristikos ir naudojant jas aptinkamos įtempto plieninio lyno paviršiuje nutrūkusios vielos buvimo vieta. Pirmasis uždavinys suformuluotas, nes atlikus literatūros apžvalgą nustatyta, kad plieninių lynų defektams aptikti naudojant dinamines charakteristikas skirta mažai dėmesio. Antrasis siejasi su pirmojo uždavinio sprendimu, nes kai matuojamos virpančios nutrūkusios vielos amplitudės, labai svarbu įvertinti matavimo priemonių patikimumą. Disertaciją sudaro įvadas, trys skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė reikšmė, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra. Pirmasis skyrius... [toliau žr. visą tekstą]
2

Modelamento do contínuo de simulações micromecânicas com base em novas teorias de comportamento plástico do material

ESTEVES, ARMANDO M 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:50:11Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:45Z (GMT). No. of bitstreams: 1 10556.pdf: 3868334 bytes, checksum: db3b8774b1e81550d9d9483f00d514f7 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
3

Оценка эффективности и финансовое обоснование политики повышения конкурентоспособности промышленной компании : магистерская диссертация / Efficiency assessment and financial justification of the policy of increasing the competitiveness of an industrial company

Храмцов, С. А., Khramtsov, S. A. January 2019 (has links)
Выпускная квалификационная работа (магистерская диссертация) посвящена исследованию оценке эффективности и финансовому обоснованию политики повышения конкурентоспособности промышленной компании. Предметом исследования выступают финансово-экономические отношения по поводу обеспечения конкурентоспособности производственной организации. Основная цель магистерской диссертации состоит в развитии теоретических и методических установок по оценке конкурентоспособности производственной компании, проведения анализа хозяйственной деятельности компании, предложить дополнение к существующим методам оценки конкурентоспособности. В заключении обозначены рекомендации по повышению конкурентоспособности для объекта исследования. / Final qualifying work (master's thesis) is devoted to the study of efficiency evaluation and financial justification of the policy of increasing the competitiveness of an industrial company. The subject of the study are the financial and economic relations on the competitiveness of the production organization. The main purpose of the master's thesis is to develop theoretical and methodological guidelines for assessing the competitiveness of the production company, the analysis of economic activity of the company, to offer an addition to the existing methods of assessing competitiveness. In conclusion, the recommendations to improve the competitiveness of the object of study.
4

A Subcorrente Norte do Brasil ao largo da Costa do Nordeste / The North Brazil undercurrent off the coast of northeast

Marin, Fernando de Oliveira 29 May 2009 (has links)
A Subcorrente Norte do Brasil (SNB) é a corrente de contorno oeste que fecha o Giro Equatorial do Oceano Atlantico em sua porc¸ ao austral. É uma corrente vigorosa, com núcleo atingindo 1ms1 em profundidades de 150ma 250 m. Trabalhos pretéritos reportam que esta corrente transporta mais de 20 Sv (1 Sv = 106 m3 s1). Ao receber o aporte de volume de ramos da Corrente Sul Equatorial (CSE), em torno de 4 S 5 S, a SNB adquire núucleo em superfície e passa a ser denominada Corrente Norte do Brasil (CNB). Entretanto, nao há relato do padrao contínuo da SNB entre 11 S e as proximidades da linha do equador, por observacões de velocidade, na literatura. O objetivo desta dissertação é justamente o mapeamento sinótico e descrição da SNB e das estruturas de mesoescala associadas na faixa latitudinal supracitada. Para tanto, combinamos dados de ADCP de casco e de hidrografia. Os dados sao oriundos das comissoes OCEANO NORDESTE I (ONEI, verao 2002) e OCEANO NORDESTE II (ONEII, primavera 2004), realizadas a bordo do NOc Antares da Marinha do Brasil. Através de cálculo de velocidades geostróficas relativas a 1.150 m, análise dos dados de velocidades perfiladas pelo ADCP de casco e cálculo de velocidades geostróficas absolutas referenciadas pelos dados de ADCP a 160 m, obtivemos uma descrição da SNB que confirma e estende esforços anteriores de pesquisa. A SNB aparece como uma corrente robusta e presente ao longo de todas as radiais analisadas. Entre 11 S e as proximidades do Cabo Calcanhar (RN), o comportamento da corrente revela pouco meandramento, seguindo o talude continental nordestino. A exceção é um ramo ciclonico em torno de 4 S que cede volume para originar a Subcorrente Sul Equatorial (SSE) em nível subpicnoclínico. A SNB, provalvemente tentando conservar vorticidade potencial, frente à abrupta mudança de orientação da margem continental em 5 S, também desenvolve vii um meandro anticiclonico frontal centrado na longitude da cidade de Macau (RN) e com cerca de 150 km de raio. Como há evidencia do anticiclone nas duas comissões, especulamos tratar-se de uma estrutura semipermanente. Por tratar-se de um relato original, decidimos denominá-lo Vórtice de Macau (VM). Outro resultado relevante foi a documentação do processo de transformação da SNB em CNB, com avaliação do núcleo se tornando mais raso em direção ao equador. No cenário da ONEII, observamos a retroflexao picnoclínica da CNB, ocorrida no hemisfério boreal e a origem da Subcorrente Equatorial (SE) na área de estudo. Também como resultado inédito, os dados de velocidade observada mostraram que também há cessao de volume pela SNB para SE em torno de 1 S. / The North Brazil Undercurrent (NBUC) is the western boundary current that closes the Equatorial Gyre of the Atlantic Ocean in its austral portion. The NBC is a vigorous current with a core that reaches 1 m s1 at depth of 150 m to 250 m. Previous works reported that this current transports more than 20 Sv (1 Sv = 106 m3 s1). As branches of the South Equatorial Current (SEC) reaches the western boundary at around 4 S 5 S, the NBUC core surfaces and the new current is referred as the North Brazil Current (NBC). However, there is no report in the literature about a continuous pattern of the NBUC in the latitude range between 11 S and the vicinities of the equator from observed velocities. The main goal of this thesis is just to obtain a synoptic map of NBUC and the associated mesoscale features in the latitude range mentioned above. In order to do so, we combined vessel-mount ADCP and hydrographic data from two cruises conducted by the R/V Antares of the Brazilian Navy: the OCEANO NORDESTE I (ONEI, summer 2002) and the OCEANO NORDESTE II (ONEII, spring 2004). We calculated geostrophic velocities relative to 1.150 m, analyzed ADCP observed velocity data as well computed absolute geostrophic velocities, referenced by the ADCP data at 160 m. Hence, we were able to obtain a NBC description that corroborated and extended the findings of previous research in the area. The NBUC was depicted as a robust nearly non-meandering current between 11 S and Cape Calcanhar (RN) present in all transects of both cruises. At 4 S, the NBUC develops a cyclonic branch and originates the South Equatorial Undercurrent (SEUC). Possibly as an attempt to conserve potential vorticity as the NBUC faces the abrupt change in the continental margin orientation at 5 S, the current develops a 150 km radius anticyclonic frontal meander. As there are evidence of the anticyclone ix in both cruises, we speculate that it can be a semipermanent feature. As it is a original description, we named it the Macau Eddy. Another result that deserves to be mentioned is that the process of the transformation of the NBUC in NBC was well documented for the first time through a continuous surfacing process of the current core. Finally, in the ONEII scenario, we observed the pycnoclinic retroflection of the NBC that occurs in northern hemisphere and returns to the equator to originate the Equatorial Undercurrent (EUC). We also depicted that the NBUC feeds the forming EUC from the southern hemisphere from a cyclonic branch around 1 S.
5

A Subcorrente Norte do Brasil ao largo da Costa do Nordeste / The North Brazil undercurrent off the coast of northeast

Fernando de Oliveira Marin 29 May 2009 (has links)
A Subcorrente Norte do Brasil (SNB) é a corrente de contorno oeste que fecha o Giro Equatorial do Oceano Atlantico em sua porc¸ ao austral. É uma corrente vigorosa, com núcleo atingindo 1ms1 em profundidades de 150ma 250 m. Trabalhos pretéritos reportam que esta corrente transporta mais de 20 Sv (1 Sv = 106 m3 s1). Ao receber o aporte de volume de ramos da Corrente Sul Equatorial (CSE), em torno de 4 S 5 S, a SNB adquire núucleo em superfície e passa a ser denominada Corrente Norte do Brasil (CNB). Entretanto, nao há relato do padrao contínuo da SNB entre 11 S e as proximidades da linha do equador, por observacões de velocidade, na literatura. O objetivo desta dissertação é justamente o mapeamento sinótico e descrição da SNB e das estruturas de mesoescala associadas na faixa latitudinal supracitada. Para tanto, combinamos dados de ADCP de casco e de hidrografia. Os dados sao oriundos das comissoes OCEANO NORDESTE I (ONEI, verao 2002) e OCEANO NORDESTE II (ONEII, primavera 2004), realizadas a bordo do NOc Antares da Marinha do Brasil. Através de cálculo de velocidades geostróficas relativas a 1.150 m, análise dos dados de velocidades perfiladas pelo ADCP de casco e cálculo de velocidades geostróficas absolutas referenciadas pelos dados de ADCP a 160 m, obtivemos uma descrição da SNB que confirma e estende esforços anteriores de pesquisa. A SNB aparece como uma corrente robusta e presente ao longo de todas as radiais analisadas. Entre 11 S e as proximidades do Cabo Calcanhar (RN), o comportamento da corrente revela pouco meandramento, seguindo o talude continental nordestino. A exceção é um ramo ciclonico em torno de 4 S que cede volume para originar a Subcorrente Sul Equatorial (SSE) em nível subpicnoclínico. A SNB, provalvemente tentando conservar vorticidade potencial, frente à abrupta mudança de orientação da margem continental em 5 S, também desenvolve vii um meandro anticiclonico frontal centrado na longitude da cidade de Macau (RN) e com cerca de 150 km de raio. Como há evidencia do anticiclone nas duas comissões, especulamos tratar-se de uma estrutura semipermanente. Por tratar-se de um relato original, decidimos denominá-lo Vórtice de Macau (VM). Outro resultado relevante foi a documentação do processo de transformação da SNB em CNB, com avaliação do núcleo se tornando mais raso em direção ao equador. No cenário da ONEII, observamos a retroflexao picnoclínica da CNB, ocorrida no hemisfério boreal e a origem da Subcorrente Equatorial (SE) na área de estudo. Também como resultado inédito, os dados de velocidade observada mostraram que também há cessao de volume pela SNB para SE em torno de 1 S. / The North Brazil Undercurrent (NBUC) is the western boundary current that closes the Equatorial Gyre of the Atlantic Ocean in its austral portion. The NBC is a vigorous current with a core that reaches 1 m s1 at depth of 150 m to 250 m. Previous works reported that this current transports more than 20 Sv (1 Sv = 106 m3 s1). As branches of the South Equatorial Current (SEC) reaches the western boundary at around 4 S 5 S, the NBUC core surfaces and the new current is referred as the North Brazil Current (NBC). However, there is no report in the literature about a continuous pattern of the NBUC in the latitude range between 11 S and the vicinities of the equator from observed velocities. The main goal of this thesis is just to obtain a synoptic map of NBUC and the associated mesoscale features in the latitude range mentioned above. In order to do so, we combined vessel-mount ADCP and hydrographic data from two cruises conducted by the R/V Antares of the Brazilian Navy: the OCEANO NORDESTE I (ONEI, summer 2002) and the OCEANO NORDESTE II (ONEII, spring 2004). We calculated geostrophic velocities relative to 1.150 m, analyzed ADCP observed velocity data as well computed absolute geostrophic velocities, referenced by the ADCP data at 160 m. Hence, we were able to obtain a NBC description that corroborated and extended the findings of previous research in the area. The NBUC was depicted as a robust nearly non-meandering current between 11 S and Cape Calcanhar (RN) present in all transects of both cruises. At 4 S, the NBUC develops a cyclonic branch and originates the South Equatorial Undercurrent (SEUC). Possibly as an attempt to conserve potential vorticity as the NBUC faces the abrupt change in the continental margin orientation at 5 S, the current develops a 150 km radius anticyclonic frontal meander. As there are evidence of the anticyclone ix in both cruises, we speculate that it can be a semipermanent feature. As it is a original description, we named it the Macau Eddy. Another result that deserves to be mentioned is that the process of the transformation of the NBUC in NBC was well documented for the first time through a continuous surfacing process of the current core. Finally, in the ONEII scenario, we observed the pycnoclinic retroflection of the NBC that occurs in northern hemisphere and returns to the equator to originate the Equatorial Undercurrent (EUC). We also depicted that the NBUC feeds the forming EUC from the southern hemisphere from a cyclonic branch around 1 S.
6

Hodnocení investičního projektu fotovoltaické elektrárny / Evaluation of the investment project of photovoltaic power plant

Marková, Lucie January 2010 (has links)
This thesis is divided into three chapters. The first chapter defines the objective of the work. The second section summarizes the theoretical and methodological part. Theoretical and methodological part deals with analysis of the area, preparation and implementation of the project, methods of evaluating investment and defines a project risk. The third part is the part of the application. It is about putting theoretical knowledge into practise. The third chapter contains an analysis of the area, description of the company, economic valuation and asessment of investment risk.
7

Оценка конкурентоспособности промышленного предприятия (на примере АО”ПО “УОМЗ им. Э.С. Яламова”) : магистерская диссертация / Assessment of competitiveness of an industrial enterprise (on the example of JSC”PO “UOMZ . after E. S. Yalamov”)

Марковских, Е. С., Markovskikh, E. S. January 2017 (has links)
Thesis is presented on 95 pages of typewritten text, consists of introduction, three chapters, conclusion, bibliography and applications, includes 6 tables, 26 figures. The bibliographic list contains 73 names, including 5 foreign. In the introduction justified the relevance of the research topic, formulate the purpose and tasks, object and subject of research, outlines the key provisions of novelty and practical significance of the work. The first Chapter analyzes the concept of competition and competitiveness. Identified levels of competitiveness, and also studied the existing methodological foundations for estimating competitiveness of business entities. The second Chapter is devoted to the analysis of the General situation and dynamics of development of separate segments of the market based on the review of basic characteristics. Also, in accordance with the dynamic method, assess the competitive status of machine-building enterprise JSC "PO "UOMZ". On the basis of what is revealed and articulated the shortcomings of the existing methods of estimation of competitiveness of business entities. Description and practical approbation of the proposed methodology for assessing the competitiveness of managing subjects for formation of a complex of measures on improvement of activities of the studied enterprises are presented in the third Chapter. In particular, the main directions of further increase of competitiveness of JSC "PO "UOMZ" is the development of measures to improve the strategic positioning of the enterprise and increased market share by segment "optical and surveying equipment". / Диссертация изложена на 97 страницах машинописного текста, состоит из введения, трех глав, заключения, списка использованной литературы и приложения, включает 6 таблиц, 26 рисунков. Библиографический список включает 73 наименования, в том числе 5 иностранных. Во введении обоснована актуальность темы исследования, сформулированы цель и задачи, объект и предмет исследования, обозначены основные положения новизны и практическая значимость работы. В первой главе проанализированы понятия конкуренции и конкурентоспособности. Выявлены уровни конкурентоспособности, а так же исследованы существующие методические основы оценки конкурентоспособности хозяйствующих субъектов. Вторая глава посвящена анализу общего положения, а так же динамики развития отдельных сегментов рынка на основе обзора базовых характеристик. Так же, в соответствии с динамическим методом, осуществлена оценка конкурентного статуса машиностроительного предприятия АО «ПО «УОМЗ». На основании чего выявлены и сформулированы недостатки существующей методики оценки конкурентоспособности хозяйствующих субъектов. Описание и практическая апробация предложенной методики оценки конкурентоспособности хозяйствующих субъектов в целях формирования комплекса мероприятий по улучшению деятельности исследуемого предприятия представлена в третьей главе. В частности, основными направлениями дальнейшего повышения конкурентоспособности АО «ПО «УОМЗ» является разработка мероприятий по улучшению стратегического позиционирования предприятия и увеличению доли рынка по сегменту «оптическое и геодезическое оборудование».
8

Оценка и пути повышения конкурентоспособности промышленного предприятия : магистерская диссертация / Assessment and ways of improving competitiveness of industrial enterprises

Горожанина, Е. П., Gorozhanina, E. P. January 2018 (has links)
Thesis is presented on 108 pages of typewritten text. Consists of introduction, three chapters, conclusion, bibliographic list, two applications, includes 10 tables and 8 figures. The bibliographic list contains 66 names including 4 foreign. In the introduction justified the relevance of the research topic, formulate the purpose and tasks, object and subject of research, outlines the key provisions of novelty and practical significance of the work. The first Chapter analyzes the concept of competition and competitiveness. The main factors and sources of competitiveness of the enterprise are revealed, the existing methods used to assess the competitiveness of economic entities are investigated. The second Chapter describes the main characteristics of the metallurgical industry at the present stage. Also it includes the review of the activities of enterprises in the context of restrictive measures by foreign States , their functioning within the framework of international organizations such as the WTO and the EAEU, as well as the main directions of development of enterprises are marked. The methodological approach to assessing the competitiveness of the enterprise and ways to improve it is presented in the third Chapter. The presented method was tested on the example of PJSC "TMK", the level of competitiveness of the enterprise was determined, on the basis of which a set of measures to improve the activity of the enterprise was proposed. / Диссертация изложена на 108 листах машинописного текста. Состоит из введения, трех глав, заключения, списка использованной литературы, двух приложений, включает 10 таблиц, 8 рисунков. Библиографический список включает 66 наименований, в том числе 4 иностранных. Во введении обоснована актуальность темы исследования, сформулированы цель и задачи, объект и предмет исследования, обозначены основные положения новизны и практической значимости работы. В первой главе проанализирована сущность понятий конкуренции и конкурентоспособности. Выявлены основные факторы и источники конкурентоспособности предприятия, а так же исследованы существующие методы, применяемые для оценки конкурентоспособности хозяйствующих субъектов. Во второй главе рассмотрены основные характеристики металлургической отрасли на современном этапе. Произведен обзор деятельности предприятий в условиях ограничительных мер со стороны иностранных государств, их функционирование в рамках таких международных организаций, как ВТО и ЕАЭС, а также обозначены основные направления развития предприятий. Методический подход к оценке конкурентоспособности предприятия и путей его повышения представлен в третьей главе. Проведена апробация представленного метода на примере ПАО «ТМК», то есть определен уровень конкурентоспособности предприятия, на основании которого предложен комплекс мероприятий по улучшению деятельности исследуемого предприятия.
9

Optimum Design Of Retaining Structures Under Static And Seismic Loading : A Reliability Based Approach

Basha, B Munwar 12 1900 (has links)
Design of retaining structures depends upon the load which is transferred from backfill soil as well as external loads and also the resisting capacity of the structure. The traditional safety factor approach of the design of retaining structures does not address the variability of soils and loads. The properties of backfill soil are inherently variable and influence the design decisions considerably. A rational procedure for the design of retaining structures needs to explicitly consider variability, as they may cause significant changes in the performance and stability assessment. Reliability based design enables identification and separation of different variabilities in loading and resistance and recommends reliability indices to ensure the margin of safety based on probability theory. Detailed studies in this area are limited and the work presented in the dissertation on the Optimum design of retaining structures under static and seismic conditions: A reliability based approach is an attempt in this direction. This thesis contains ten chapters including Chapter 1 which provides a general introduction regarding the contents of the thesis and Chapter 2 presents a detailed review of literature regarding static and seismic design of retaining structures and highlights the importance of consideration of variability in the optimum design and leads to scope of the investigation. Targeted stability is formulated as optimization problem in the framework of target reliability based design optimization (TRBDO) and presented in Chapter 3. In Chapter 4, TRBDO approach for cantilever sheet pile walls and anchored cantilever sheet pile walls penetrating sandy and clayey soils is developed. Design penetration depth and section modulus for the various anchor pulls are obtained considering the failure criteria (rotational, sliding, and flexural failure modes) as well as variability in the back fill soil properties, soil-steel pile interface friction angle, depth of the water table, total depth of embedment, yield strength of steel, section modulus of sheet pile and anchor pull. The stability of reinforced concrete gravity, cantilever and L-shaped retaining walls in static conditions is examined in the context of reliability based design optimization and results are presented in Chapter 5 considering failure modes viz. overturning, sliding, eccentricity, bearing, shear and moment failures in the base slab and stem of wall. Optimum wall proportions are proposed for different coefficients of variation of friction angle of the backfill soil and cohesion of the foundation soil corresponding to different values of component as well as lower bounds of system reliability indices. Chapter 6 presents an approach to obtain seismic passive resistance behind gravity walls using composite curved rupture surface considering limit equilibrium method of analysis with the pseudo-dynamic approach. The study is extended to obtain the rotational and sliding displacements of gravity retaining walls under passive condition when subjected to sinusoidal nature of earthquake loading. Chapter 7 focuses on the reliability based design of gravity retaining wall when subjected to passive condition during earthquakes. Reliability analysis is performed for two modes of failure namely rotation of the wall about its heel and sliding of the wall on its base are considering variabilities associated with characteristics of earthquake ground motions, geometric proportions of wall, backfill soil and foundation soil properties. The studies reported in Chapter 8 and Chapter 9 present a method to evaluate reliability for external as well as internal stability of reinforced soil structures (RSS) using reliability based design optimization in the framework of pseudo static and pseudo dynamic methods respectively. The optimum length of reinforcement needed to maintain the stability against four modes of failure (sliding, overturning, eccentricity and bearing) by taking into account the variabilities associated with the properties of reinforced backfill, retained backfill, foundation soil, tensile strength and length of the geosynthetic reinforcement by targeting various component and system reliability indices is computed. Finally, Chapter 10 contains the important conclusions, along with scope for further work in the area. It is hoped that the methodology and conclusions presented in this study will be beneficial to the geotechnical engineering community in particular and society as a whole.
10

Contribution à l'analyse structurelle des systèmes singuliers pour la conception mécatronique / Structural analysis of descriptor systems for modeling and design of mechatronic systems

Lagnier, Julien 02 June 2017 (has links)
Cette thèse s'inscrit dans le cadre de la conception des systèmes mécatroniques. Les travaux se positionnent dans les premières phases du cycle de conception, là où les principaux efforts méthodologiques sont à mener pour améliorer la qualité et la fonctionnalité des produits, et reposent sur le prototypage virtuel (modélisation et simulation). Une approche méthodologique envisageable est de reformuler le problème de conception sous une forme inverse, pour directement utiliser les spécifications du cahier des charges, usuellement exprimées sur les sorties, pour calculer les inconnues du problème. Dans ce contexte, le laboratoire Ampère développe une méthodologie de conception et dimensionnement, basée sur l'inversion de modèle, utilisant le formalisme bond graph, pour proposer une démarche reposant sur des critères dynamiques et énergétiques, et dont la principale originalité est sa phase d'analyse structurelle, permettant une hiérarchisation d’analyse suivant différents niveaux de la structure physique du modèle (topologie, phénoménologie, paramétrage). L'objectif est de contribuer au développement de cette méthodologie, en l’étendant aux modèles appartenant à la classe des systèmes singuliers, porté par la velléité de décliner la démarche à la conception fonctionnelle du châssis automobile et de ses sous-systèmes, comportant un certain nombre d'abstractions de modélisation et d'idéalisations. Cette déclinaison est proposée, d’une part, au niveau de la structure du modèle et, d’autre part, à un niveau considérant sa phénoménologie et ses lois de comportement. Elle requiert la mise en place préalable d'un référentiel algébrique, essentiellement issu de travaux sur la commande des systèmes, pour constituer une base de validation des extensions graphiques (digraphe et bond graph) proposées. En plus de la généralisation qu'ils constituent à la classe des modèles singuliers, les présents travaux proposent une uniformisation des précédentes approches de la méthodologie, originellement appliquées respectivement aux modèles directs et aux modèles inverses, de sorte qu'il n'est à présent plus nécessaire de les différencier. / The context of this PhD thesis is the modeling and design of mechatronic systems. The study is positioned in the early design stage of the conception cycle (V-Cycle), where the main efforts have to be produced in terms of methodology, to enhance the quality and the functionality of the products, and based on virtual prototyping (modeling and simulation). One of the possible methodology is to reformulate the design problem as an inverse problem, in order to directly use the design specification of the product, usually given in terms of the system outputs, and then solve the design problem. In this context, the Ampere laboratory of INSA Lyon has developed a conception and design methodology, based on inverse approach and using the bond graph formalism, to propose a step-by-step method based on dynamic and energetic criteria, with a structural analysis phase that allows hierarchical analysis steps, depending on the structural physical layout of the model (topological, phenomenological, parameter set). The aim of the present works is to contribute to the development of this methodology, by enhancing it to the class of descriptor systems. This choice is led by the aim to apply the methodology in the context of chassis design and vehicle dynamics, where, among other, multi-body models represented as a differential-algebraic equation (DAE) system could occur. The contributions are proposed at the level of the topology of the model, as well as at the level of the phenomenological / behavioral aspects. A preliminary step is to enhance the existing algebraic framework to support graphical extension (in term of digraph and bond graph). The overall methodological extensions allow, firstly, a generalization of the approach to the class of descriptor systems, and, secondly, to reach a standardization of the procedures, previously dedicated to direct or inverse models, so as no mandatory differences between those models have to be done anymore.

Page generated in 0.0206 seconds