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  • 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.
141

Porovnání cen ovocných dřevin zjištěných zjednodušeným a výnosovým způsobem / Comparison of Fruit Trees Prices Ascertained by the Simplified and Yield Method

Jašová, Alena January 2012 (has links)
The Thesis „Comparison of fruit trees prices ascertained by the simplified and yield method“ deals with the comparison of both pricing methods, where there are defined factors on the basis of ascertained facts which have essential influence on price difference of fruit trees and subsequently the proposal to their modification is made.
142

Porovnání cen venkovních úprav na pozemku ve funkčním celku s rodinným domem stanovených nákladovým a zjednodušeným způsobem ve vybrané lokalitě v Brně / Comparison of Prices for External Works on a Land Parcel in a Functional Unit with a Family House Determined via the Cost Method and in a Simplified Manner at a Chosen Location in Brno

Říha, Milan January 2012 (has links)
The aim of the thesis is to assess the influence of the exterior finish works on the total price of a house. The total price of the house consists of the interior price valuated by the cost method and the price of the exterior finishes which were valuated with the help of two methods: the cost method and the simplified method based on the Property Valuation Act. The valuation also covers several periods of time: a new building and 11-, 25-, 50-, 75- and 100-years-old buildings. The thesis focuses on the lifetime of individual parts of the exterior finishes—especially the time after which it is necessary to replace or reconstruct a part. A significant focus was placed on the percents listed in the Act and their correspondence to the actual state. The thesis also deals with the various methods of valuation and their appropriateness in each case. It also mentions the influence of other factors on the price of an estate (the use of different exterior finishes, or a selection of a building location) but these factors were not examined in detail.
143

Neutron transport in hexagonal reactor cores modeled by trigonal-geometry diffusion and simplified P3 nodal methods

Duerigen, Susan January 2013 (has links)
The superior advantage of a nodal method for reactor cores with hexagonal fuel assemblies discretized as cells consisting of equilateral triangles is its mesh refinement capability. In this thesis, a diffusion and a simplified P3 (or SP3) neutron transport nodal method are developed based on trigonal geometry. Both models are implemented in the reactor dynamics code DYN3D. As yet, no other well-established nodal core analysis code comprises an SP3 transport theory model based on trigonal meshes. The development of two methods based on different neutron transport approximations but using identical underlying spatial trigonal discretization allows a profound comparative analysis of both methods with regard to their mathematical derivations, nodal expansion approaches, solution procedures, and their physical performance. The developed nodal approaches can be regarded as a hybrid NEM/AFEN form. They are based on the transverse-integration procedure, which renders them computationally efficient, and they use a combination of polynomial and exponential functions to represent the neutron flux moments of the SP3 and diffusion equations, which guarantees high accuracy. The SP3 equations are derived in within-group form thus being of diffusion type. On this basis, the conventional diffusion solver structure can be retained also for the solution of the SP3 transport problem. The verification analysis provides proof of the methodological reliability of both trigonal DYN3D models. By means of diverse hexagonal academic benchmark and realistic detailed-geometry full-transport-theory problems, the superiority of the SP3 transport over the diffusion model is demonstrated in cases with pronounced anisotropy effects, which is, e.g., highly relevant to the modeling of fuel assemblies comprising absorber material.
144

Kundanpassad LCA för nätverkskameror / Customized LCA for Network Cameras

Hillerström, Hanna, Troborg, Ulrika January 2010 (has links)
Antalet övervakningskameror i samhället ökar, samtidigt som deras miljöpåverkan är relativt okänd. För en produkt som tidigare bara utvärderats gällande prestanda, börjar kunderna nu efterfråga en kartläggning av miljöpåverkan. Kamerans miljöpåverkan studeras ur ett livscykelperspektiv: energi- och materialtillförsel samt utsläpp och avfall som berör allt ifrån råmaterialutvinning till slutåtervinning. Projektet är genomfört på begäran av, och för, Axis Communications AB (härmed refererade till som Axis) med huvudsyfte att öka Axis kunskap om deras produkters miljöpåverkan och utveckla en metod för genomförande av förenklade livscykelanalyser på Axis produkter. Livscykelanalysen, LCA, genomförs på en nätverkskamera utvecklad av Axis Communications AB; modell AXIS Q6032-E PTZ. Samtidigt togs metoden för förenklade livscykelanalyser fram för att möjliggöra jämförelse med andra kameramodeller i företagets produktportfolio. Även en plattform har skapats för att kunna användas i produktutvecklingens tidigare skede, för att redan där göra ett aktivt miljöval. Den metod som används för bedömning av miljöpåverkan är Eco-indicator 99. Simulering och beräkningar sker i LCA-programmet SimaPro 7.1.Resultatet visar att den största miljöpåverkan kommer ifrån användningsfasen och behovet av elektricitet. För scenariot där kameran används i Europa har tillverkningen näst störst påverkan, därefter materialanvändningen och sist transporterna. Återvinningen påverkar med ett negativt värde, d.v.s. den påverkar miljön på ett positivt sätt. Det alternativa scenariot (där kameran flygs till USA och installeras där) ger en totalt större miljöpåverkan och har transporterna som andra värsta kategorin. Vid beräkningar för Europa släpper kameran ut 663 kg CO2 under sin livstid. Den utvecklade modellen överensstämmer till 0,24% med resultatet ifrån simuleringsprogrammet. Modellen kan enligt den genomförda känslighetsanalysen anses stabil / The number of surveillance cameras installed for various purposes have increased substantially in society over the past decade. The environmental impacts from network cameras are relatively unknown and their rapid increase in number calls for studying the impacts from a life cycle perspective; from raw material extraction to decommissioning. The project is performed on request by Axis Communications AB (hereby referred to as Axis) with the main purposes to increase Axis's knowledge of the environmental impact from their products and establish a method for conducting simplified life cycle assessments (LCA) on Axis products. A case study LCA is conducted on a network camera developed by Axis; model AXIS Q6032-E PTZ. Concurrently a method for conducting simplified LCAs on other Axis cameras is developed as well as a platform to be used in product development processes to enhance life cycle thinking (LCT). The Eco-indicator 99 Method is used for the environmental impact assessment and for simulations and calculations the software program SimaPro 7.1 is used.The results emphasize the life stages and their particular activities having the largest potential environmental impacts; primarily utilization and the production of electricity. For the scenario where the camera is installed in Europe the manufacturing comes as second, then raw material extraction and processing, followed by transportations. Decommissioning impacts with a negative value, i.e. impacts the environment in a positive way. The alternative scenario (where the camera is transported by air to U.S. and installed there) gives a total higher score and has the transportation category as the second highest regarding the total environmental impact. During the whole lifetime the camera emits 663 kg CO2.The results from using the developed model to conduct simplified LCAs only differ by 0.24% from the results of the case study LCA. The LCA is considered stable based on the performed sensitivity analysis.
145

Kinematic Behaviour of Cross Laminated Timber (CLT) Shearwalls with Openings

Mestar, Mohammed 03 September 2020 (has links)
An integrated experimental and numerical research program investigating the elastic and inelastic performance as well as the kinematic behaviour of shearwalls with openings is presented in this study. The influence of the geometrical dimensions of the wall configurations and the mechanical properties and configurations of hold-downs on both elastic and inelastic behaviours including the possible kinematic modes of the shearwalls are investigated. The research also proposes the concept of equivalent-frame-model applicable for shearwalls where openings are cut-out from CLT panels. Are also presented, five racking tests performed on full scale CLT walls in order to validate the numerical models as well as the equivalent frame model. From review of the available literature emerges that for CLT shearwalls with openings, studies are not at the same level of abundance in research compared to walls without openings, due to the simple reason that SSW is generally a widespread technique. Thus, the kinematic behaviour and the coupling effect are inexistent and presented here. The investigations of the wall’s behaviour in the elastic and inelastic ranges demonstrate the important effect of the lintel and wall segment slenderness as well as the hold-down stiffness effect on the mechanical behaviour and the global kinematic behaviour as well. It is found that the kinematic modes can change when the walls are stressed beyond their elasticity limit. The failure mode and the global ductility are highly dependent on the hold-down configurations particularly for walls with door openings. The degree of coupling decrease with increased hold-down stiffness and the wall segment width. With regards to the equivalent frame model, a reasonable fit is found between the proposed EFM and a detailed 2D area element model when the global elastic stiffness and tensile load in the hold-down were compared. The model is successfully validated through five full-scale tests on CLT shearwalls with door or window opening as well as two published studies on walls with door openings. The EFM is capable of predicting the behaviour in the wall with reasonable accuracy, especially for walls whose behaviour was dominated by the hold-down behaviour.
146

Interakce člověka s robotem: pokročilá úkolově orientovaná rozhraní pro neodborné uživatele / Human-Robot Interaction: Advanced Task-centered Interfaces for Non-Expert Users

Materna, Zdeněk Unknown Date (has links)
Poslední roky přinesly rostoucí trend nasazení robotů v nových aplikacích, kde se od nich očekává nejen práce vedle lidí, ale skutečná spolupráce na společných komplexních úlohách. K umožnění blízké, bohaté a přirozené interakce člověka s robotem, bude nutné podstatně rozšířit schopnosti současných robotických systémů. Dále již nebude docházet k interakci jen mezi roboty v bezpečnostních klecích a experty na jejich programování. Stále častěji budou interagovat s~bezpečnými spolupracujícími roboty uživatelé bez odborných znalostí z oblasti robotiky, s různorodým vzděláním a zkušenostmi. Úžasně složitá zařízení, kterými dnešní roboti jsou, se tak stanou ještě složitějšími, což představuje zásadní výzvu pro návrh jejich uživatelských rozhraní. Cílem této práce je zkoumat a vyvinout řešení umožňující blízkou interakci mezi neodbornými uživateli a komplexními roboty. Výzkum byl zaměřen na dvě oblasti robotiky: asistenční servisní a průmyslové spolupracující roboty. Ačkoliv se tyto dvě oblasti vyznačují odlišnými požadavky, pro návrh interakce mezi člověkem a~robotem je možné použít podobné principy. Nedostatky stávajících přístupů jsou řešeny návrhem nové metody pro úlohově zaměřenou interakci. Nejvýznamější aspekty metody jsou využití smíšené reality, autonomních funkcí robota, komunikace vnitřního stavu robota, kontextová citlivost a použití modalit vhodných pro danou úlohu. Pro obě oblasti zaměření výzkumu bylo na základě metody navrženo a implementováno uživatelské rozhraní. Obě rozhraní byla úspěšně ověřena s neodbornými uživateli, kteří díky nim byli schopni úspěšně spolupracovat s robotem na složitých úlohách. Publikovaná ověření rozhraní prokazují, že realizovaná metoda významně zlepšuje blízkou interakci mezi člověkem a robotem, která s dosavadními přístupy nebyla plně dosažitelná. Klíčové aspekty metody představují vodítko pro návrh uživatelských rozhraní v oblasti spolupracujících robotů.
147

Implementeringen av EU:s tjänstedirektiv i svensk rätt : Principerna om god förvaltning i EU:s tjänstedirektiv och processuell autonomi vid implementering av direktivet i svensk rätt

Hajdini, Adelina January 2022 (has links)
The aim of this study is to examine how Sweden has implemented directive 2006/123/EC of the European Parliament and of the council of 12 December 2006 on services in the internal market, in the framework of the member states procedural- and institutional autonomy. The study will focus on the contributions to the Swedish law in the form of expressions of the principle of good administration, as a result of the implementation of the directive. The expressions of the principle of good administration were found in the main law "Act (2009:1079) on services in the internal market" where the majority of the directive's provisions were implemented in Swedish law. The study focuses on two expressions of the principle that simultaneously are news in Swedish law induced by the implementation of The Services Directive: the principle of necessity and liaison points of the authorities. With basis in the study of the implementation of The Services Directive as an EU secondary law act in Swedish law and the new expressions of the principle of good administration in Swedish law to fulfill the directive - the purpose of the study will include an analysis of the EU-law's impact on Swedish Administrative Law with focus on the legislation's format. The analysis will, among other things, refer to the different administrative law traditions in the two legal systems regarding the status of general principles of law, mainly the principle of good administration, in the field of administrative law.
148

Flödeseffektivisering och systematisk effektivisering av fabrikslayout vid lokalbyte för Permanova Lasersystem AB / Flow efficiency and systematic streamlining of the factory layout at the facility move for Permanova Laser Systems AB

Palmblad, Oscar January 2021 (has links)
Marknaden för industriella lasersystem förväntas att växa i framtiden, vilket leder till att producenter utav dessa system måste förbereda sig för att möta marknadens krav. Ett av dessa företag är Permanova Lasersystem AB som arbetar med att ta fram lasersystem, legotillverkning och optik för kunder. Målet med detta projekt är att öka produktionen av standardoptik från stycktillverkning till 50 optik/år och att hjälpa Permanova ta fram en layout till deras nya anläggning som de ska flytta till. Målen för projektet kan delas in i tre huvudmål: • Ta fram ett optimalt produktionsflöde • Ta fram en optimal fabrikslayout • Ta fram optimala arbetsstationer För att uppnå dessa mål har metoder inom LEAN applicerats, såsom värdeflödesanalyser, 7+1 slöseri, kanban, Just in time och flaskhalsanalyser. För att ta fram optimala layouter för företaget har även förenklad systematisk lokalplanläggning applicerats. För att skapa ett optimalt produktionsflöde skapades först en värdeflödesanalys för nuvärdet, vilket visade på hur produktionen sker idag samt vilka förbättringsmöjligheter som finns. Till denna nuvärdesanalys gjordes en tidsstudie på nuvarande standardoptik som låg i grunden för senare balansering i produktionen. En värdeflödesanalys för framtida produktion utvecklades från nuvärdesanalysen och dess förbättringsmöjligheter, vilket gav ett nytt produktionsflöde med en mer optimal affärsmodell för framtiden. Förenklad systematisk lokalplanläggning applicerades i 3 iterationer, en för varje utrymme som projektet arbetade med. Dessa tre iterationer var för huvudlayouten, verkstaden och renrummet. För huvudlayouten fanns det 3 huvudkoncept där verkstadens placering styrde vart de andra av Permanovas affärsområden placerades. Det vinnande av dessa huvudkoncept vidareutvecklades och skapade en layout som uppfyllde alla företagets krav samt de flesta av deras önskemål. Flera verkstadslayouter togs fram för varje huvudlayout, där det vinnande konceptet utvecklades vidare till ett koncept som applicerar värdeflödesanalysen för framtiden väl. Denna layout minimerar transportsträckor mellan arbetsstationerna och ökar produktiviteten. För renrummet utvecklades flera koncept men för endast ett utrymme då alla renrumsytor liknande varandra. Det vinnande konceptet vidareutvecklades och skapade en layout som är lik dagens produktion i renrummet, vilket var något som montören ansåg fördelaktigt. / The market for industrial laser systems is expected to grow in the future, which means that manufacturers of these systems must prepare to meet market demands. One of these companies is Permanova Lasersystem AB, which works with developing laser systems, contract manufacturing and optics for customers. The goal of this project is to increase the production of standard optics from single-piece production to 50 optics/year and to help Permanova develop a layout for their new facility, which they will move to. The goals of the project can be divided into three main goals: • Develop an optimal production flow • Develop an optimal factory layout • Develop optimal workstations To achieve these goals, methods within LEAN have been applied, such as value steam mapping, 7 + 1 wastes, kanban, Just in time and bottleneck analysis. To produce optimal layouts for the company, simplified systematic layout planning has also been applied. In order to create an optimal production flow a value stream map for the present production was created, which showed how the production works today and what opportunities for improvement exist. For this value stream map a time study was made on the current standard optic, which was the basis for later balancing in the production. A value stream map for the future state of production was also developed from the first value stream map and its opportunities for improvement, which provided a new production flow with a more optimal business model for the future. Simplified systematic layout planning was applied in 3 iterations, one for each area the project worked on. These three iterations were for the main layout, the workshop and the clean room. For the main layout there were 3 main concepts where the workshop's location controlled where the other of Permanova's business areas were located. The winning of these main concepts was further developed and created a layout that met all the company's requirements as well as most of their wishes. Several workshop layouts were developed for each main layout, where the winning concept was further developed into a concept that applies the value steam map for the future well. This layout minimizes transport distances between workstations and helps increase productivity. For the clean room, concepts were developed for only one of the possible spaces because all clean room spaces were similar to each other. The winning concept was further developed and created a layout that is like today's production in the clean room, which was something that the operator considered advantageous.
149

Footbridge Dynamics : Human-Structure Interaction

Zäll, Emma January 2018 (has links)
For aesthetic reasons and due to an increased demand for cost-effective and environmentally friendly civil engineering structures, there is a trend in designing light and slender structures. Consequently, many modern footbridges are susceptible to excessive vibrations caused by human-induced loads. To counteract this, today's design guidelines for footbridges generally require verification of the comfort criteria for footbridges with natural frequencies in the range of pedestrian step frequencies. To ensure that a certain acceleration limit is not exceeded, the guidelines provide simplified methodologies for vibration serviceability assessment. However, shortcomings of these methodologies have been identified. First, for certain footbridges, human-structure interaction (HSI) effects might have a significant impact on the dynamic response. One such effect is that the modal properties of the bridge change in the presence of a crowd; most importantly, the damping of the bridge is increased. If this effect is neglected, predicted acceleration levels might be overestimated. Second, as a running person induces a force of greater amplitude than a walking person, a single runner might cause a footbridge to vibrate excessively. Hence, the running load case is highly relevant. These two aspects have in common that they are disregarded in existing design guidelines. For the stated reasons, the demand for improvements of the guidelines is currently high and, prospectively, it might be necessary to require the consideration of both the HSI effect and running loads. Therefore, this licentiate thesis aims at deepening the understanding of these subjects, with the main focus being placed on the HSI effect and, more precisely, on how it can be accounted for in an efficient way. A numerical investigation of the HSI effect and its impact on the vertical acceleration response of a footbridge was performed. The results show that the HSI effect reduces the peak acceleration and that the greatest reduction is obtained for a crowd to bridge frequency ratio close to unity and a high crowd to bridge mass ratio. Furthermore, the performance of two simplified modelling approaches for consideration of the HSI effect was evaluated. Both simplified models can be easily implemented and proved the ability to predict the change in modal properties as well as the structural response of the bridge. Besides that, the computational cost was reduced, compared to more advanced models. Moreover, a case study comprising field tests and simulations was performed to investigate the effect of runners on footbridges. The acceleration limit given in the design guideline was exceeded for one single person running across the bridge while a group of seven people walking across the bridge did not cause exceedance of the limit. Hence, it was concluded that running loads require consideration in the design of a footbridge. / På grund av estetiska skäl och en ökad efterfrågan på kostnadseffektiva och miljövänliga konstruktioner är merparten av de gångbroar som konstrueras idag förhållandevis lätta och slanka. Med anledning av detta ökar risken för att stora svängningar uppstår på grund av dynamisk belastning från människor på bron. För att motverka att detta inträffar kräver dagens normer att komforten verifieras för gångbroar med egenfrekvenser inom området för människans stegfrekvens. Komforten verifieras genom att säkerställa att ett visst accelerationskriterium inte överskrids. För detta ändamål finns handböcker som tillhandahåller förenklade beräkningsmetoder för uppskattning av accelerationsnivåer. Brister i dessa beräkningsmetoder har emellertid identifierats. För det första kan olika typer av människa-bro-interaktion (HSI) ha en betydande inverkan på responsen hos vissa broar. Exempel på en HSI-effekt är att brons modala egenskaper förändras när människor befinner sig på bron; i huvudsak sker en ökning av brons dämpning. Om denna effekt inte tas i beaktande föreligger stor risk att överskatta förväntade accelerationsnivåer. För det andra är kraften från en löpare större än kraften från en gående person vilket gör att en ensam löpare på en gångbro kan ge upphov till accelerationsnivåer som överskrider gränsvärdena för komfort. Löpande personer är därför ett mycket relevant lastfall. Befintliga normer uttrycker inte explicit att någon av dessa aspekter bör tas i beaktande. Behovet av förbättrade riktlinjer för hur normerna bör tillämpas är därför mycket stort och i framtiden kan det bli nödvändigt att kräva att både HSI-effekter och löparlaster tas i beaktande. Därför syftar denna licentiatavhandling till att bidra till en fördjupad förståelse inom dessa två ämnen, med huvudfokus på ovan nämnda HSI-effekt i allmänhet och hur den kan beaktas på ett enkelt, noggrant och tidseffektivt sätt i synnerhet. En numerisk undersökning av HSI-effekten och dess inverkan på den vertikala responsen hos en gångbro genomfördes. Resultaten visar att HSI-effekten reducerar den maximala accelerationen och att störst reduktion erhålls då folksamlingen och bron har ungefär samma egenfrekvens och då folksamlingens massa är stor i förhållande till brons massa. Vidare utvärderades två förenklade metoder för beaktande av HSI-effekten vilka kan implementeras av konstruktörer med grundläggande kunskaper inom strukturdynamik. Det konstaterades att båda metoderna uppskattar HSI-effekten såväl som brons respons förhållandevis väl samtidigt som de reducerar beräkningstiden något jämfört med mer avancerade metoder. Effekten av löpare på gångbroar studerades genom en fallstudie med fältmätningar. Utifrån resultaten från dessa fältmätningar kunde det konstateras att accelerationsgränsen som anges i normerna överskreds när en ensam löpare sprang över bron men inte när en grupp på sju personer gick i takt över samma bro. Därför drogs slutsatsen att löparlaster bör tas i beaktande vid dimensionering av en gångbro. / <p>QC 20180320</p>
150

[es] ESTUDIO DEL MÉTODO HÍBRIDO DE LOS ELEMENTOS DE CONTORNO Y PROPUESTA DE UNA FORMULACIÓN SIMPLIFICADA / [pt] ESTUDO DO MÉTODO HÍBRIDO DOS ELEMENTOS DE CONTORNO E PROPOSTA DE UMA FORMULAÇÃO SIMPLIFICADA / [en] STUDY OF THE HYBRID BOUNDARY ELEMENT METHOD AND THE PROPOSAL OF A SIMPLIFIED FORMULATION

RICARDO ALEXANDRE PASSOS CHAVES 19 February 2001 (has links)
[pt] O Método Híbrido dos Elementos de Contorno foi formulado em 1987. Desde então, este método tem sido aplicado com sucesso a diversos tipos de problemas de elasticidade e potencial, inclusive problemas dependentes do tempo. Porém, alguns aspectos importantes do método permaneceram abertos a investigação. Esta dissertação apresenta três contribuições, com desenvolvimentos feitos para problemas de elasticidade, mas prontamente extensíveis a problemas de potencial. Numa primeira etapa, desenvolve-se uma expressão para os resultados de deslocamentos no domínio, levando-se em conta corretamente a parcela de deslocamentos de corpo rígido. A partir deste primeiro desenvolvimento, é proposta uma formulação simplificada do método, na qual uma matriz de flexibilidade é obtida diretamente, num procedimento que dispensa qualquer tipo de integração. Esta nova formulação, como mostrado nos exemplos numéricos, é extremamente precisa e de simples implementação computacional. No entanto, por não ter uma base variacional, esta formulação conduz a uma matriz de rigidez não-simétrica. Na terceira contribuição, o Método Híbrido dos Elementos de Contorno e o Método Híbrido Simplificado dos Elementos de Contorno são aplicados a problemas gerais de meio infinito, para qualquer tipo de condições de contorno. Para isto é mostrado que as propriedades espectrais de ambos os métodos estão interrelacionadas. Apresenta-se um grande número de resultados numéricos de problemas bidimensionais, para validação dos desenvolvimentos teóricos realizados. / [en] The hybrid boundary element method was introduced in 1987. Since then, the method has been applied successfully to different problems of elasticity and potential, including time-dependent problems. However, some important aspects of the method have remained open to investigation. This dissertation consists in a threefold contribution, with developments outlined for elasticity, but readily extensible to potential problems. The first step is aimed at improving the expression of displacement results in the domain by taking correctly into account the amount of rigid body movements. Based on the assessment of displacements, a simplified formulation of the method is proposed, in which a flexibility-like matrix is directly obtained, in a procedure that requires no integration at all. This novel formulation, as shown in the numerical examples, is extremely accurate and rather inexpensive. Since it lacks a variational basis, however, the method leads to a non-symmetric stiffness matrix. In a third step, both hybrid and simplified boundary element methods are extended to general problems in an infinite domain, for any type of boundary conditions. It is shown that the matrices of both methods are spectrally interrelated. A large number of numerical results of two-dimensional problems validate the theoretical achievements. / [es] El Método Híbrido de los Elementos de Contorno fue formulado en 1987. Desde entonces, este método ha sido aplicado con éxito a diversos tipos de problemas de elasticidad y potencial, incluso en problemas dependientes del tiempo. No obstante, algunos aspectos importantes del método han permanecido abiertos a la investigación. Esta disertación presenta tres contribuciones, desarrolladas para problemas de elasticidad, pero perfectamente extendibles a problemas de potencial. En una primeira etapa, se desarrolla una expresión para los resultados de deslocamientos en el dominio, teniendo en cuenta la parcela correcta de deslocamientos del cuerpo rígido. A partir de este primer desarrollo, se propone una formulación simplificada del método, en el cual, se obtiene una matriz de flexibilidad diretamente, a través de un procedimiento que dispensa cualquier tipo de integración. Esta nueva formulación, como muestran los ejemplos numéricos, es extremamente precisa y de simple implementación computacional. Sin embargo, por no tener una base variacional, esta formulación conduce a una matriz de rígidez no simétrica. En la tercera contribución, se aplican el Método Híbrido de los Elementos de Contorno y el Método Híbrido Simplificado de los Elementos de Contorno a problemas gerales de medio infinito, para cualquier tipo de condiciones de contorno. Para ello, se demuestra que las propriedads espectrales de ambos métodos están interrelacionadas. Con el objetivo de evaluar los desarrollos teóricos aquí abordados se presentan un gran número de resultados numéricos de problemas bidimensionales.

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