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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.
51

Modélisation des forces de contact entre le pneu d’un avion et la piste / Modeling the contact forces between an aircraft tire and the runway

Jones, Logan 26 June 2012 (has links)
Lorsqu’un avion atterrit, la force principale nécessaire pour arrêter l’avion est obtenue par le freinage. Par une réduction de la vitesse de rotation des roues, les freins provoquent une vitesse de glissement entre les pneus et la piste. C’est cette différence de vitesse qui génère la force de freinage capable de stopper l’avion. La modélisation de cette force est essentielle pour l’estimation de la longueur de piste à l’atterrissage. Les modèles classiques utilisés par les avionneurs sont assez simplistes et dérivent expérimentalement des modèles de frictions les plus simples. De sorte que ces modèles sont dans l’incapacité d’estimer l’influence de paramètres clefs influençant la force de freinage. Il s’agit, en particulier de la pression des pneus, de la nature de la gomme, de la température ambiante et de celle de la gomme, de l’état de la piste, de sa texture, etc. L’objectif de la thèse a été de développer un modèle de contact pneu-piste capable d’estimer la force de freinage. C’est le « Brush Model » qui a servi de base à cette modélisation. En phase de freinage la zone de contact est constituée d’une première zone de déformation de la gomme qui crée une force résistante en suivant la loi de Hooke, puis d’une seconde zone de glissement dont la force de résistance suit la loi de Coulomb. Ce modèle a été amélioré grâce aux résultats de la mécanique des structures pour la loi de Hooke et grâce aux résultats de la tribologie pour la loi de Coulomb. Ces deux modélisations faisant appel aux données issues de la science des matériaux. L’ensemble de ces modélisations a été enrichi par une coopération avec plusieurs centres de recherches ayant fourni de nombreux résultats expérimentaux. Le modèle obtenu a ensuite été confronté avec des résultats d’essais en vol obtenus avec « Airbus Operations S.A.S ». La thèse a validé le prétraitement des données d’essais ainsi que le processus d’identification qui a permis de montrer l’accord du modèle avec les résultats expérimentaux obtenus lors des essais en vol. Cette modélisation donne des résultats très encourageants, elle permet une compréhension beaucoup plus approfondie des effets de l’environnement sur les forces de freinage. De sorte que cette thèse a permis d’améliorer très sensiblement la compréhension fondamentale des phénomènes en jeu lors du freinage, au contact entre le pneu et la piste. Chez Airbus, les résultats obtenus vont servir de base pour les travaux à venir sur ce thème. / As an aircraft lands on a runway, the principal force acting to stop the aircraft within the confines of the runway is generated by the brakes. The brakes cause the tire’s rotational speed to slow down with regards to the aircraft’s speed over the ground. This difference in speed causes friction and it is this friction that is the principal force to stop the aircraft. In order to be able to estimate the stopping distance of an aircraft an understanding of this friction is essential. Traditionally, aircraft manufactures have relied on simplistic, empirically derived friction models. However, these empirical models cannot estimate the influence of several key factors that are known (scientifically) to affect friction such as the rubber temperature, the runway texture, the ambient air temperature and the rubber composition to name a few. This PhD work aims to develop a frictional model that can be used to estimate the friction developed between an aircraft tire and the runway. A model commonly known as the Brush Model, is derived for usewith aircraft tires and runways. The underlying physics of this model are developed using the established scientific theories of tribology, material science and strength of materials. Coordination with several research institutes provides experimental results to reinforce the model. The model is then compared with flight test results obtained from a partnership with Airbus OperationsS.A.S. The PhD works demonstrates the entire validation process from flight test data cleaning, the derivation of a curve-fitting algorithm and the matching of derived model with the flight test data. The modeling has shown very encouraging results. It allows for a much deeper understanding of the environmental effects on friction. This PhD work has greatly improved the fundamental understanding of friction and will serve as a base for future works with Airbus.
52

O modelo QRSP para a quantificação do risco na saída de veículos da pista em rodovias / The QRSP model to quantify the risk in the runway exit of vehicles on highways

Andrade, Cândido Moreira 19 September 2011 (has links)
Uma parcela significativa dos acidentes de trânsito nas rodovias ocorre devido à saída de veículos da pista, o que pode resultar em choques com obstáculos fixos, quedas em espaços vazios, tombamento, capotagem, etc. Esse tipo de acidente é, em geral, grave, em razão das altas velocidades desenvolvidas nas rodovias. Cerca de 1/3 dos acidentes rodoviários com vítimas fatais nos Estados Unidos resultam de saída de pista. No Brasil, estima-se que 30% dos acidentes rodoviários estão relacionados com saída da pista, sendo esse valor da ordem de 25% nos casos dos acidentes com vítimas fatais. Neste trabalho é apresentado o Modelo QRSP (formado pelas letras iniciais das palavras: Quantificação - Risco - Saída - Pista) em rodovias. O modelo permite quantificar o nível de proteção existente em cada segmento particular da rodovia (análise microscópica) e, a partir dessa informação, quantificar o nível de proteção considerando trechos longos (análise macroscópica). No modelo desenvolvido, a avaliação é feita considerando separadamente os dois lados da pista (direito e esquerdo), podendo os resultados serem compostos no caso da quantificação de trechos longos. O modelo foi desenvolvido para o caso de rodovias de múltiplas faixas por sentido (denominadas comumente de pista dupla), podendo, no entanto, também ser empregado no caso das rodovias de duas faixas e duplo sentido (rodovias de pista simples). O modelo QRSP permite determinar parâmetros não fornecidos pelos métodos ABNT (2007) - norma brasileira - e AASHTO (2002) - norma americana, proporcionando, dessa forma, uma melhor quantificação do risco na saída de veículos da pista. A análise dos resultados fornecidos pelo modelo QRSP mostra que o mesmo representa a realidade de maneira satisfatória. As informações quantitativas fornecidas pelo modelo são de grande utilidade na elaboração de projetos de melhoria das características das laterais de rodovias existentes, bem como na preparação de projetos de novas rodovias. / A significant portion of road traffic accidents on highways occurs because of the exit of vehicles from the runway, which may result in collisions with fixed obstacles, falls in empty spaces, overturning, roll over, etc. This kind of accident is in general quite severe, due to the high speeds on highways. Approximately one third of road accidents with fatalities in the United States result from the runway exit. In Brazil, it is estimated that 30% of road accidents are also related to the runway exit, bringing this value at 25% in the cases of accidents with fatal victims. The QRRE that stands for Quantification the Risk in the Runway Exit of vehicles on highways is presented in this research. The model allows to quantify the level of protection in each particular segment of the highway (microscopic analysis) and from this information, it permits to quantify the level of protection considering long segments (macroscopic analysis). In the developed model, the assessment is done considering separately the left and right sides of the runway, and the results can be compounded in the case of long segments quantification. The model was developed for the case of multilanes highways in each direction, however, this model can also be used in the case of two lanes highways with two-ways direction. The QRRE model allows to determine parameters that are not provided by the methods ABNT (2007) - Brazilian standard, - and AASHTO (2002) - American standard, which provides a better measurement of risk in the exit of vehicles from the runway. The results obtained by QRRE model show that it clearly represents the reality. The quantitative information provided by the model are useful for the development of projects in order to improve the characteristics of the roadside highways available, and the development of projects for new highways.
53

Análise numérica de vigas de rolamento de aço sem contenção lateral entre apoios / Numerical analysis of crane runway girders of steel without lateral bracing between supports

Leite, Luiz Rafael dos Santos 01 February 2017 (has links)
As vigas de rolamento são estruturas destinadas ao suporte de pontes rolantes, estas amplamente utilizadas para movimentação de cargas em galpões industriais. O presente trabalho apresenta um estudo sobre as vigas de rolamento de aço sem contenção lateral entre apoios, em geral projetadas com vão inferior a 7 metros, portanto destinadas ao suporte de pontes rolantes leves (capacidade nominal até 250 kN). A ausência de contenções laterais intermediárias aliada ao desalinhamento e à imprecisão na locação dos trilhos, bem como à presença de forças horizontais transversais ao eixo da viga (aceleração/frenagem do trole), impõem flexão lateral e torção, esforços que são equilibrados apenas pelas contenções nos apoios. A análise foi realizada utilizando o Método dos Elementos Finitos (MEF), considerando a análise não linear física e geométrica do problema, ou seja, um modelo mais próximo da viga real. Os resultados numéricos, quando comparados aos obtidos por meio da teoria de flexo-torção, mostraram uma inversão na distribuição esperada de tensões na mesa superior do perfil, ou seja, nos pontos onde deveria ocorrer aumento da tensão longitudinal de compressão, ocorreu redução. Esta inversão pode ou não ocorrer, dependendo da espessura da mesa superior, intensidade e posição da força vertical da roda da ponte. Além disso, os resultados determinados via MEF foram comparados com os obtidos via modelo tradicional de barra (momento de torção substituído por um binário de forças horizontais nas mesas). A comparação indicou divergência entre os resultados, podendo o dimensionamento pelo modelo de barra levar tanto a situações a favor da segurança como contra a segurança. / The runway girders are structures intended for support cranes, these broadly used to movement of loads in industrial buildings. This research presents a study about the runway girders without lateral bracing between support points, generally designed with span lower than 7 meters, therefore intended for support of light cranes (rated capacity until 250 kN). The absence of intermediate lateral bracing allied to misalignment and imprecision location of the rail, also the presence of the side thrust on the girder (acceleration/ braking of the trolley), causes lateral flexural and torsion, which are balanced only by the lateral containment on support points. The analysis was made using the Finite Element Method (FEM), which includes a nonlinear physical and geometric analysis of the structural problem, in other words, a model closest to the real girder. The numerical results, when compared to the results of the flexural-torsional theory, showed an inversion in the expected distribution of stress on the top flange of the shape, in other words, at the points where must occur increase of the longitudinal stress, reduction occurred. This inversion may or may not occur, depending on the thickness of the top flange, modulus and position of the load of the crane wheel. Besides, the numerical results were compared with the results of classical bar model for beams (torque is replaced by a couple of horizontal forces applied on the flanges). The comparison showed a divergence between the results, where the design by bar classical model can lead to situations of high safety or against safety.
54

Área de escape para caminhões desgovernados / Escape areas for runaway trucks

Zanoli, Paulo Rogério 14 April 2003 (has links)
O objetivo desta dissertação foi estudar dispositivos para contenção de veículos desgovernados por falta de freios em declives longos e íngremes. Para tanto, fez-se uma revisão abrangente da literatura especializada e coletaram-se dados em testes realizados na área de escape construída no km 42,7 da pista sul da Via Anchieta, onde existe um declive de 12,8 km de extensão. A pesquisa relatada nesta dissertação focaliza três aspectos principais: a eficiência do dispositivo em deter caminhões sem freios, a localização do dispositivos e a determinação da velocidade segura de operação de caminhões nesse declive. Dados empíricos da desaceleração dos caminhões no dispositivo foram coletados com auxílio de GPS, o que permitiu estudar o comportamento dos caminhões dentro da caixa de retenção. Os dados coletados foram usados para a calibração de um modelo capaz de estimar a desaceleração média proporcionada pelo dispositivo em função da velocidade de entrada e do número de eixos do caminhão. Para a análise da localização do dispositivo, propôs-se um modelo que leva em consideração o perfil vertical do declive, a velocidade dos caminhões, a temperatura dos freios e a frequência de acidentes com veículos desgovernados ao longo do declive. A determinação da estratégia ótima de condução no declive consistiu em determinar a máxima velocidade que os caminhões podem percorrer o declive sem que os freios sofram superaquecimento. Os parâmetros usados na análise foram a massa bruta total do veículo e as reduções da sua caixa de câmbio. Foram estabelecidas velocidades e marchas máximas para 16 tipos de caminhão. Os resultados obtidos mostram que este tipo de dispositivo é capaz de deter caminhões desgovernados com segurança e podem subsidiar projetos de novas áreas de escape no Brasil. / The objective of the dissertation was to study devices for arresting runaway trucks on long and steep downgrades. A comprehensive review of the literature was carried out and empirical data were collected by means of real life trials at an arrester bed build at a 12.8 km downgrade on the southward lanes of Via Anchieta, the old highway connecting the cities of São Paulo and Santos, in Brazil. The research reported focused on three major aspects: arresting capability of the escape area, location of the escape area and safe operating speeds for trucks on this downgrade. Truck deceleration data were collected during the trials by means of GPS equipment installed in the vehicles and were used to determine truck behavior within the arrester bed. A mathematical model, which allows the estimation of average deceleration as a function of entry speed and number of axles, was fitted to the observed data. The location study proposed a method to establish the points along the downgrade where arrester beds are needed, based on road profile, truck speed, brake temperature and accident data. Optimal driving strategies for truck drivers to negotiate safely the downgrade were also studied, in order to determine the downgrade maximum speed that would avoid brake overheating. The parameters used in this analysis were gross vehicle mass and gearbox characteristics. Safe maximum downgrade speeds and gears were established for 16 truck models. The results, which showed that arrester beds are capable of safely stopping runaway trucks in long and steep downgrades, may also be used to assist the design of new arrester beds in Brazil.
55

Área de escape para caminhões desgovernados / Escape areas for runaway trucks

Paulo Rogério Zanoli 14 April 2003 (has links)
O objetivo desta dissertação foi estudar dispositivos para contenção de veículos desgovernados por falta de freios em declives longos e íngremes. Para tanto, fez-se uma revisão abrangente da literatura especializada e coletaram-se dados em testes realizados na área de escape construída no km 42,7 da pista sul da Via Anchieta, onde existe um declive de 12,8 km de extensão. A pesquisa relatada nesta dissertação focaliza três aspectos principais: a eficiência do dispositivo em deter caminhões sem freios, a localização do dispositivos e a determinação da velocidade segura de operação de caminhões nesse declive. Dados empíricos da desaceleração dos caminhões no dispositivo foram coletados com auxílio de GPS, o que permitiu estudar o comportamento dos caminhões dentro da caixa de retenção. Os dados coletados foram usados para a calibração de um modelo capaz de estimar a desaceleração média proporcionada pelo dispositivo em função da velocidade de entrada e do número de eixos do caminhão. Para a análise da localização do dispositivo, propôs-se um modelo que leva em consideração o perfil vertical do declive, a velocidade dos caminhões, a temperatura dos freios e a frequência de acidentes com veículos desgovernados ao longo do declive. A determinação da estratégia ótima de condução no declive consistiu em determinar a máxima velocidade que os caminhões podem percorrer o declive sem que os freios sofram superaquecimento. Os parâmetros usados na análise foram a massa bruta total do veículo e as reduções da sua caixa de câmbio. Foram estabelecidas velocidades e marchas máximas para 16 tipos de caminhão. Os resultados obtidos mostram que este tipo de dispositivo é capaz de deter caminhões desgovernados com segurança e podem subsidiar projetos de novas áreas de escape no Brasil. / The objective of the dissertation was to study devices for arresting runaway trucks on long and steep downgrades. A comprehensive review of the literature was carried out and empirical data were collected by means of real life trials at an arrester bed build at a 12.8 km downgrade on the southward lanes of Via Anchieta, the old highway connecting the cities of São Paulo and Santos, in Brazil. The research reported focused on three major aspects: arresting capability of the escape area, location of the escape area and safe operating speeds for trucks on this downgrade. Truck deceleration data were collected during the trials by means of GPS equipment installed in the vehicles and were used to determine truck behavior within the arrester bed. A mathematical model, which allows the estimation of average deceleration as a function of entry speed and number of axles, was fitted to the observed data. The location study proposed a method to establish the points along the downgrade where arrester beds are needed, based on road profile, truck speed, brake temperature and accident data. Optimal driving strategies for truck drivers to negotiate safely the downgrade were also studied, in order to determine the downgrade maximum speed that would avoid brake overheating. The parameters used in this analysis were gross vehicle mass and gearbox characteristics. Safe maximum downgrade speeds and gears were established for 16 truck models. The results, which showed that arrester beds are capable of safely stopping runaway trucks in long and steep downgrades, may also be used to assist the design of new arrester beds in Brazil.
56

Optimisation du réseau de routes en zone terminale / Aircraft route network optimization in terminal maneuvering area

Liang, Man 02 February 2018 (has links)
La congestion dans les Terminal Manoeuvring Area (TMA) des aéroports en hub est le principal problème dans le transport aérien chinois. Face au trafic extrêmement dense dans les TMAs, nous pouvons envisager d'automatiser une grande partie des opérations de routine, comprenant la planification, le séquencement et la séparation. Nous proposons dans cette thèse un nouveau système automatisé de séquencement des avions et de fusion des flux vers des pistes parallèles, qui sont utilisées dans la plupart des aéroports chinois. Notre méthodologie intègre un réseau de route 3D nommé Multi-Level and Multi-Point Merge System (MLMPMS) basé sur le concept de l'Area Navigation (RNAV) et un algorithme d'optimisation heuristique hybride pour trouver une solution correcte, opérationnellement acceptable. Un algorithme de Simulated Annealing (SA) spécifique et un module de génération de trajectoire collaborent pour rechercher la solution quasi optimale. Notre objectif est de générer en temps réel des trajectoires sans conflit, minimisant la consommation de carburant et permettant des méthodes de contrôle faciles et flexibles. Dans ce but, nous explorons en permanence les solutions possibles avec le moins de retard et assuront l'atterrissage le plus rapide. Nous déterminons quatre variables de décision pour contrôler chaque vol : l'heure et la vitesse d'entrée dans la TMA, le temps de vol sur l'arc de séquencement et le choix de la piste utilisée. La simulation de trajectoire dans les différentes phases de vol est basée sur le modèle de performances BADA. Dans le cas de l'aéroport de Beijing Capital International Airport (BCIA), les résultats numériques montrent que notre système d'optimisation de bonnes performances sur le séquencement et la fusion des trajectoires. Tout d'abord, il permet d'assurer des performances de résolution conflit très stables pour gérer les flux de trafic continuellement denses. Par rapport à l'algorithme Hill Climbing (HC), le SA peut toujours trouver une solution sans conflit, non seulement pour l'approche parallèle mixte ou séparée~(pour les arrivées), mais aussi pour les configurations parallèles indépendantes~ (départs et arrivées intégrés). Ensuite, avec un réseau d'itinéraires Multi-Level Point Merge (ML-PM) unique, il peut fournir une bonne solution de contrôle de la trajectoire pour traiter efficacement et économiquement différents types de flux d'arrivée. Il peut réaliser un temps de vol plus court et une descente vers le bas en Continuous Descent Approach (CDA) pour l'avion d'arrivée. Il peut réaliser un re-séquencement plus facile des avions avec un déplacement de position plus relâché. Théoriquement, les Maximum Position Shifting (MPS) peuvent atteindre 6 positions, surpassant la contrainte difficile de 3 positions. Troisièmement, l'algorithme montre son efficacité dans un modèle d'approche parallèle séparé avec une capacité de séquencement plus relâché. Par rapport au décalage de position forcé dur, qui est souvent utilisé dans le système actuel Arrival Manager (AMAN) et la méthode First Come First Served (FCFS) utilisé par les contrôleurs, il peut réduire le délai et le temps de transit moyens dans une situation d'arrivée très dense. Le palier par vol est inférieur à 12\% du temps de transit total dans la TMA. Quatrièmement, en configuration parallèle indépendant, il peut fournir des informations différentes concernant la valeur objectif associée, le temps de vol moyen, les trajectoires de croisement en point chaud entre les arrivées et les départs, l'efficacité avec différents arcs de séquencement conçus dans le réseau de route ML-PM etc.. / Congestion in Terminal Manoeuvring Area (TMA) at hub airports is the main problem in Chinese air transportation system. Facing extremely dense operations in complex TMA, we can consider reducing traffic complexity by solving all potential conflicts in advance with a feasible trajectory control for controllers, or automating a large proportion of routine operations, such as sequencing, merging and spacing. As parallel runways are a common structure of Chinese hub airports, in this thesis, we propose a novel system to integrated sequencing and merging aircraft to parallel runways. Our methodology integrates a Area Navigation (RNAV)-based 3D Multi-Level and Multi-Point Merge System (MLMPMS), a hybrid heuristic optimization algorithm and a simulation module to find good, systematic, operationally-acceptable solutions. First, a Receding Horizon Control (RHC) technique is applied to divide 24-hour traffic optimization problem into several sub- problems. Then, in each sub-problem, a tailored Simulated Annealing (SA) algorithm and a trajectory generation module worn together to find a near-optimal solution. Our primary objective is to rapidly generate conflict-free and economical trajectories with easy, flexible and feasible control methods. Based on an initial solution, we continuously explore possible good solutions with less delay and shorter landing interval on runway. Taking Beijing Capital International Airport (BCIA) as a case to study, numerical results show that our optimization system performs well. First, it has very stable de-conflict performance to handle continuously dense traffic flows. Compared with Hill Climbing (HC), the tailored SA algorithm can always guarantee a conflict-free solution not only for the mixed or segregated parallel approach (arrivals only) pattern, but also for the independent parallel operation (integrated departures and arrivals) pattern. Second, with its unique Multi-Level Point Merge (ML-PM) route network, it can provide a good trajectory control solution to efficiently and economically handle different kinds of arrival flows. It can realize a shorter flying time and a near-Continuous Descent Approach (CDA) descent for arrival aircraft, compared with baseline. It also realizes an easier re-sequencing of aircraft with more relaxed position shifting as well, compared with conventional sequencing method. Theoretically, the Maximum Position Shifting (MPS) can be up to 6 positions, overcoming the hard constraint of 3 position shifts (MPS <= 3). Third, it is efficient for the segregated parallel approach patterns. Compared with hard constrained position shifting, which is often used in current Arrival Manager (AMAN) system and controller's manual-control First Come First Served (FCFS) method, it can reduce the average delay, average additional transit time in super dense arrival situations. The average time flown level per flight is less than 12% of total transit time in TMA. Fourth, in independent parallel patterns, it can provide a range of useful information concerning the associated objective value, the average flying time, crossing trajectories in hot spots between arrivals and departures, the efficiency of using different designed sequencing legs in ML-PM route network.
57

Measuring Airport Efficiency with Fixed Asset Utilization to Minimize Airport Delays

Widener, Scott D. 22 October 2010 (has links)
Deregulation of the airlines in the United States spawned a free-for-all system which led to a variety of agents within the aviation system all seeking to optimize their own piece of the aviation system, and the net result was that the aviation system itself was not optimized in aggregate, frequently resulting in delays. Research on the efficiency of the system has likewise focused on the individual agents, primarily focusing on the municipalities in an economic context, and largely ignoring the consumer. This paper develops the case for a systemic efficiency measurement which incorporates the interests of the airlines and the consumers with those of the airport operating municipalities in three different Data Envelopment Analysis (DEA) models: traditional Charnes-Cooper-Rhodes and Banker-Charnes-Cooper models, and a Directional Output Distance Function model, devised and interpreted using quality management principles. These models were combined to allow the resulting efficiencies of the operating configurations of the given airport to predict the efficiency of the associated airport. Based upon regression models, these efficiency measurements can be used as a diagnostic for improving the efficiency of the entire United States airspace, on a systemic basis, at the individual airport configuration level. An example analysis using this diagnostic is derived in the course of the development and description of the diagnostic and two additional case studies are presented.
58

A Programming Framework To Implement Rule-based Target Detection In Images

Sahin, Yavuz 01 December 2008 (has links) (PDF)
An expert system is useful when conventional programming techniques fall short of capturing human expert knowledge and making decisions using this information. In this study, we describe a framework for capturing expert knowledge under a decision tree form and this framework can be used for making decisions based on captured knowledge. The framework proposed in this study is generic and can be used to create domain specific expert systems for different problems. Features are created or processed by the nodes of decision tree and a final conclusion is reached for each feature. Framework supplies 3 types of nodes to construct a decision tree. First type is the decision node, which guides the search path with its answers. Second type is the operator node, which creates new features using the inputs. Last type of node is the end node, which corresponds to a conclusion about a feature. Once the nodes of the tree are developed, then user can interactively create the decision tree and run the supplied inference engine to collect the result on a specific problem. The framework proposed is experimented with two case studies / &quot / Airport Runway Detection in High Resolution Satellite Images&quot / and &quot / Urban Area Detection in High Resolution Satellite Images&quot / . In these studies linear features are used for structural decisions and Scale Invariant Feature Transform (SIFT) features are used for testing existence of man made structures.
59

O modelo QRSP para a quantificação do risco na saída de veículos da pista em rodovias / The QRSP model to quantify the risk in the runway exit of vehicles on highways

Cândido Moreira Andrade 19 September 2011 (has links)
Uma parcela significativa dos acidentes de trânsito nas rodovias ocorre devido à saída de veículos da pista, o que pode resultar em choques com obstáculos fixos, quedas em espaços vazios, tombamento, capotagem, etc. Esse tipo de acidente é, em geral, grave, em razão das altas velocidades desenvolvidas nas rodovias. Cerca de 1/3 dos acidentes rodoviários com vítimas fatais nos Estados Unidos resultam de saída de pista. No Brasil, estima-se que 30% dos acidentes rodoviários estão relacionados com saída da pista, sendo esse valor da ordem de 25% nos casos dos acidentes com vítimas fatais. Neste trabalho é apresentado o Modelo QRSP (formado pelas letras iniciais das palavras: Quantificação - Risco - Saída - Pista) em rodovias. O modelo permite quantificar o nível de proteção existente em cada segmento particular da rodovia (análise microscópica) e, a partir dessa informação, quantificar o nível de proteção considerando trechos longos (análise macroscópica). No modelo desenvolvido, a avaliação é feita considerando separadamente os dois lados da pista (direito e esquerdo), podendo os resultados serem compostos no caso da quantificação de trechos longos. O modelo foi desenvolvido para o caso de rodovias de múltiplas faixas por sentido (denominadas comumente de pista dupla), podendo, no entanto, também ser empregado no caso das rodovias de duas faixas e duplo sentido (rodovias de pista simples). O modelo QRSP permite determinar parâmetros não fornecidos pelos métodos ABNT (2007) - norma brasileira - e AASHTO (2002) - norma americana, proporcionando, dessa forma, uma melhor quantificação do risco na saída de veículos da pista. A análise dos resultados fornecidos pelo modelo QRSP mostra que o mesmo representa a realidade de maneira satisfatória. As informações quantitativas fornecidas pelo modelo são de grande utilidade na elaboração de projetos de melhoria das características das laterais de rodovias existentes, bem como na preparação de projetos de novas rodovias. / A significant portion of road traffic accidents on highways occurs because of the exit of vehicles from the runway, which may result in collisions with fixed obstacles, falls in empty spaces, overturning, roll over, etc. This kind of accident is in general quite severe, due to the high speeds on highways. Approximately one third of road accidents with fatalities in the United States result from the runway exit. In Brazil, it is estimated that 30% of road accidents are also related to the runway exit, bringing this value at 25% in the cases of accidents with fatal victims. The QRRE that stands for Quantification the Risk in the Runway Exit of vehicles on highways is presented in this research. The model allows to quantify the level of protection in each particular segment of the highway (microscopic analysis) and from this information, it permits to quantify the level of protection considering long segments (macroscopic analysis). In the developed model, the assessment is done considering separately the left and right sides of the runway, and the results can be compounded in the case of long segments quantification. The model was developed for the case of multilanes highways in each direction, however, this model can also be used in the case of two lanes highways with two-ways direction. The QRRE model allows to determine parameters that are not provided by the methods ABNT (2007) - Brazilian standard, - and AASHTO (2002) - American standard, which provides a better measurement of risk in the exit of vehicles from the runway. The results obtained by QRRE model show that it clearly represents the reality. The quantitative information provided by the model are useful for the development of projects in order to improve the characteristics of the roadside highways available, and the development of projects for new highways.
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Aplicação do modelo de previsão de acidentes do Highway Safety Manual no perímetro urbano cortado por rodovia de mão dupla e pista simples

Motta Júnior, Liércio Feital 27 October 2017 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2017-12-20T18:44:42Z No. of bitstreams: 1 lierciofeitalmottajr.pdf: 12311012 bytes, checksum: fed882b800dc53c0a497d3bda1094a0e (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: Favor corrigir no título: Higway Safety Manual on 2017-12-21T10:39:55Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2017-12-21T11:54:23Z No. of bitstreams: 1 lierciofeitalmottajr.pdf: 12311012 bytes, checksum: fed882b800dc53c0a497d3bda1094a0e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-12-22T11:59:40Z (GMT) No. of bitstreams: 1 lierciofeitalmottajr.pdf: 12311012 bytes, checksum: fed882b800dc53c0a497d3bda1094a0e (MD5) / Made available in DSpace on 2017-12-22T11:59:40Z (GMT). No. of bitstreams: 1 lierciofeitalmottajr.pdf: 12311012 bytes, checksum: fed882b800dc53c0a497d3bda1094a0e (MD5) Previous issue date: 2017-10-27 / No presente trabalho, é realizada a aplicação do modelo de previsão de acidentes do Higway Safety Manual – HSM, publicado pela American Association of State Highway and Transportation Officials (AASTHO) no ano de 2010, à rodovia de mão dupla e pista simples, BR–116, que corta perímetros urbanos de cidades no segmento entre Caratinga e Leopoldina, Minas Gerais. Busca-se avaliar a pertinência de sua utilização como ferramenta de sistemas de gestão de segurança rodoviária. Foram coletados dados de acidentes ocorridos nos trechos de estudo referentes ao intervalo entre 2011-2015, dados sobre o volume de tráfego, além de dados geométricos da via e das suas características ambientais. Foram analisadas as aplicações do modelo em sua condição base, calibrada e refinada pelo método empírico de Bayes. Como resultado da aplicação na condição base observou-se uma discrepância entre os valores de acidentes ocorridos e previstos pelo modelo, inviabilizando a utilização direta desta aplicação. A aplicação do modelo calibrado apresentou resultados mais próximos aos reais valores de acidentes, porém ainda não sendo possível a sua utilização como modelo de previsão de acidentes. No entanto, os valores obtidos pela aplicação do modelo do HSM refinado pelo método empírico de Bayes aproximam-se de maneira satisfatória dos valores de acidentes reais ocorridos, permitindo agora a sua utilização como modelo de previsão de acidentes, tendo sua aplicação como ferramenta de sistemas de gestão de segurança rodoviária. Apesar de ainda serem necessários estudos para melhoria da calibração e da condição base, às características especificas presentes no ambiente do perímetro urbano cortado por rodovias, o modelo aplicado neste trabalho pode ser utilizado como modelo de previsão de acidentes para estes trechos. / In the present work, the Higway Safety Manual - HSM, published by the American Association of State Highway and Transportation Officials (AASTHO), is applied to the double-lane and single-lane highway BR-116, which cuts urban in the segment between Caratinga and Leopoldina, Minas Gerais. The aim of this study was to evaluate the pertinence of its use as a tool for road safety management systems. Data were collected on accidents occurring in the study sections referring to the interval between 2011-2015, data on traffic volume, as well as geometric data of the road and their environmental characteristics. The applications of the model were analyzed in their base condition, calibrated and refined by Bayes' empirical method. As a result of the application in the base condition it was observed a discrepancy between the values of accidents occurred and foreseen by the model, making it impossible to use this application directly. The application of the calibrated model presented results closer to the actual values of accidents, but it is not yet possible to use them as an accident prediction model. However, the values obtained by applying the HSM model refined by the empirical method of Bayes approach satisfactorily the values of real accidents occurred, allowing now its use as an accident prediction model, having its use as a tool of systems of road safety management. Although still necessary studies to improve the calibration and the base condition, to the specific characteristics present in the environment of the urban perimeter cut by highways, the model applied in this work can be used as a predictive model of accidents for these stretches.

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