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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.
11

Projeto, construção e teste de um boneco de ensaio de dispositivos de retenção infantil / Project, construction and testing of a dummy for testing child restraint systems

Jorge, Alexandre Fonseca 14 August 2018 (has links)
Orientadores: Antonio Celso Fonseca de Arruda, Paulo Roberto Gardel Kurka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-14T02:53:31Z (GMT). No. of bitstreams: 1 Jorge_AlexandreFonseca_M.pdf: 2455128 bytes, checksum: 714a30d7c2214aa6edc9a048f74aa56d (MD5) Previous issue date: 2006 / Resumo: Um dispositivo de retenção infantil, a ser certificado pela norma NBR14400, tem como um dos principais requisitos atingir determinados níveis de performance em ensaios de impacto. Durante seu desenvolvimento, o dispositivo deve ser submetido a esse teste várias vezes, até ser aprovado, o que envolve altos custos. Este estudo propõe um teste de impacto simplificado, não para substituir o teste de certificação, mas na condição de teste de desenvolvimento preliminar e eliminatório. O principal equipamento envolvido, neste estudo, é o boneco de testes, que possui simplificações tanto na parte biomecânica quanto na parte de instrumentação. Como vantagem, quando comparado ao boneco instrumentado completo, seu custo é significativamente menor. Neste trabalho são apresentadas as condições de contorno envolvidas no projeto, na construção e no uso desse boneco. Adicionalmente, são reportados os resultados comparativos dos ensaios de impacto entre o boneco construído e o instrumentado completo Hybrid III. Tais resultados validam a proposta do projeto / Abstract: A child restraint system, to be certified to NBR 14400 standard, has as one of its main requirements, to reach specific performance levels under impact tests. During its development, the device has to undergo several times such tests, which are expensive, until approval. This study proposes a simplified impact test, not to replace the certification test, but as a preliminary and eliminatory test. The main equipment involved in this study is the test dummy, which has simplifications both on biomechanical and instrumentation aspects. As an advantage, when compared to a complete instrumented dummy, it has a considerably lower cost. In this work, the guiding conditions involved in the project, construction and use of that dummy are presented. Also, the results of comparative impact testes between the projected dummy and the complete instrumented dummy Hybrid III are reported. Such results validate the proposal of the project / Mestrado / Mestre em Engenharia Mecânica
12

Évaluation et modélisation des dispositifs de retenue pour motards / Design and Assessment of Motorcyclists Restraint Systems

Kodjo, Vidjannagni 02 September 2016 (has links)
En France, en 2015 les motocyclistes représentent 43% des blessés graves victimes d'accidents de la circulation routière. Au même moment, même si les accidents de chocs de motocyclistes contre les dispositifs de retenue routiers ne représentent en moyenne que 10% des accidents de la circulation routière, les motocyclistes présentent un risque de décès 30 à 80 fois supérieur au risque de décès des usagers de véhicules impliqués dans le même type d'accidents.Pour renforcer la sécurité des motocyclistes, les dispositifs de retenue pour automobiles (dispositifs traditionnels) sont équipés à leur partie inférieure d'écran de protection motards. Les écrans motards ont pour but d'amortir de manière progressive les chocs des motocyclistes en les empêchant dans le même temps de passer à travers la partie inférieure des dispositifs de retenue pour automobiles, de percuter un poteau et d'être sévèrement blessés. Les écrans motards doivent subir des essais de chocs normatifs et répondre à certaines exigences afin de pouvoir être installés sur le bord des routes européennes et de garantir surtout la sécurité des motards. Cependant, il n'existe que des procédures normatives pour tester ces dispositifs, la procédure LIER dans le contexte Français et la procédure normative EN 1317-8 dans le contexte Européen. Afin d'évaluer ces deux procédures normatives et de proposer de nouvelles dispositions pouvant servir de procédure normative plus avancée sur le protocole d'essais d'évaluation de performances d'écrans motards, des simulations numériques ont été réalisées. Un modèle numérique complet de dispositif de retenue routier équipé d'écran motard en acier a été développé et corrélé sur un essai de choc réel sur un dispositif de même type. Une fois corrélé,le modèle a été utilisé afin d'évaluer l'influence des conditions d'essais et des caractéristiques mécaniques matériaux de l'écran sur les performances de l'écran motard. Enfin, une nouvelle démarche d'évaluation de performances d'écran de protection motard a été mise en place / In France, in 2015,motorcyclists represent 43% of seriously injured accident victims in road traffic. At the same time, even though motorcyclists impact crashes against the road restraint systems represent on average 10% of accidents in road traffic, motorcyclists present a risk of death from30 to 80 times upper than the risk of death for users of vehicles involved in the same type of accidents. To enhance the safety of motorcyclists, Vehicle Restraints Systems (VRS) arefitted to the lower part of restraint systems for motorcyclists. Motorcyclist’s Restraint Systems (MRS) are designed to absorb shocks gradually and to preventmotorcyclists to pass through the lower part of VRS, to hit a post and be severely injured. Before being installed on the roadsides, MRS have to be crash-tested according to standards in order to evaluate their safety and ensure motorcyclists safety. However, there are only normative procedures to testMRS, the LIER procedurein the French context and the procedure EN1317-8 in the European context. To assess both normative procedures and propose new provisions which can be used as normative procedure more advanced on the protocol of MRS performances evaluation tests, numerical simulations were performed. A numerical model of MRS was developed and correlated on one real impact test on other device of same type. Once correlated, the model was used to conduct a parametric study on the test conditions and thematerialsmechanical properties of the MRS. Finally, a new demarche of MRS performances evaluation was developed
13

Analyse de sensibilité et robustesse dans le génie industriel : méthodologies et applications aux essais de chocs / Sensitivity and robustness in industrial engineering : methodologies and applications to crash tests

Qian, Gengjian 05 April 2017 (has links)
Plus d'un million de personnes meurent dans des accidents sur les routes du monde et beaucoup de millions sont gravement blessés chaque année. Selon les études, ‘Run-Off-Road accidents (ROR)’, c'est-à-dire que le véhicule a au moins une collision avec des équipements routiers, représentent environ 10% des accidents routières, mais 45% de tous les accidents mortels sont des ROR. Les dispositifs de retenue des véhicules (DDR) sont les infrastructures installées sur la route pour fournir un niveau de confinement du véhicule ‘hors de contrôle’. La barrière de sécurité routière est un DDR continu installé à côté ou sur la réserve centrale d'une route pour empêcher les véhicules errants de s'écraser sur les obstacles routiers et de les conserver en toute sécurité. Les résultats statistique montrent que l'existence des barrières peut réduire les morts jusqu'à un facteur de 4 par rapport aux collisions contre d'autres obstacles routiers. Les performances de sauvetage d'un DDR dépendent de la conception de l'appareil. Des normes telles que EN1317 ont normalisé les conditions des essais de chocs sous lesquelles une conception de DDR doit être testée et ont défini les critères pour l'évaluation des performances d'une conception. En fait, un DDR ne puisse pas vraiment être optimisé: il existe des critères multiples pour l'évaluation de la performance d'un DDR et tous les critères ne peuvent pas être optimisés en même temps; les conditions de travail d’un DDR, c'est-à-dire les conditions d'impact d’un DDR avec un véhicule errant, sont nombreuses; les facteurs incertains du DDR peuvent dégrader les performances d'une conception. La thèse vise à définir une approche qui peut servir : l'analyse de sensibilité (AS) et la conception robuste du DDR ; enrichissement des normes existantes dans la conception du DDR. Le cas d'une barrière de sécurité routière est spécifié dans l'étude : une barrière a été testée expérimentalement, le programme Ls-Dyna est utilisé pour la simulation de choc de l'appareil ; en tenant compte des propriétés du modèle de choc, les efficacités de différentes méthodes de l’AS ont été étudiées ; les influences des facteurs critiques dont les incertitudes contribuent le plus à l'instabilité de la barrière ont été quantifiées avec les approches d’AS sélectionnées ; compte tenu des incertitudes des facteurs critiques, l’optimisation robuste de multi-objectif de la barrière est réalisée ; des simulations d'impact de la barrière optimisée ont été effectuées sous des conditions d'impact différentes pour évaluer ses performances dans les véritables accidents. Les approches présentées dans l'article peuvent être utiles pour la conception d'autres DDR ou plus largement d'autres systèmes d'ingénierie complexes. On peut espérer que l'analyse de robustesse et l'analyse de la généralisation (c'est-à-dire l'évaluation de la performance du DDR sous différentes conditions d'impact) du DDR pourraient enrichir les normes de la conception des DDR / More than 1 million people die in crashes on the world’s roads and many millions are seriously injured each year. According to the studies: Run-Off-Road accidents (ROR), i.e. the vehicle run-off the road into the roadside and has at least one collision with either roadside equipment or the roadside itself, “represent about 10% of the total road accidents, while 45% of all fatal accidents are ROR”. Vehicle Restraint Systems (VRS) are the infrastructures installed on the road to provide a level of containment for an errant vehicle. Safety barrier is “continuous VRS installed alongside, or on the central reserve, of a road to prevent errant vehicles from crashing on roadside obstacles, and to retain them safely”. Statistic results show that “the existence of protective barriers on road can reduce fatalities up to a factor of 4 when compared to collisions against other road obstacles.” The life-saving performances of a VRS depend on the design of the device. Standards such as EN1317 normalized the impact conditions under which a design of VRS must be tested by crash tests, and defined the criteria for performance evaluation of a design. While a VRS cannot really be optimized: Multi-criteria exist for performance evaluation of a VRS and all the criteria cannot be optimized in the same time; the impact conditions of the VRS with the errant vehicle are numerous; uncertain factors of the VRS may degrade the performances of a design. The thesis aims to define an approach that can serve: sensitivity analysis (SA) and robust design of the VRS; Enrichment for the existing standards in the design of VRS. The case of a safety barrier is specified in the study: a safety barrier has been test experimentally, the program Ls-Dyna was used for crash simulation of the device; considering properties of the crash model, efficiencies of different SA methods were studied and influences of the critical factors whose uncertainties contribute the most to the instability of the barrier were quantified with the selected SA approaches; considering the uncertainties of the critical factors, Multi-Objective robust optimization of the tested barrier were realized; under different impact conditions, crash simulations of the optimized barrier were carried out to evaluate its performances in the real crash accidents. The approaches presented in the article can be useful for the design of other VRS or more broadly, other complex engineering systems. Hopefully, the robustness analysis and generalization analysis (i.e. performance evaluation of the VRS under different impact conditions) of the safety barrier could enrich the standards for the design of VRS
14

Projeto e construção de simulador de ensaios dinâmicos para dispositivos de retenção infantis / Project and construction of dynamic simulator for testing the child's restraint systems

Souza, Victor Cesar de, 1989- 26 August 2018 (has links)
Orientador: Antonio Celso Fonseca de Arruda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T12:30:34Z (GMT). No. of bitstreams: 1 Souza_VictorCesarde_M.pdf: 2933493 bytes, checksum: ad3ab87009ea90dcb39a5fd7757c4c9a (MD5) Previous issue date: 2015 / Resumo: Projeto, construção e avaliação de desempenho de simulador de testes de impacto de dispositivos de retenção infantis. A solução construtiva objetivou simular uma colisão automobilística e utiliza manequins representativos de crianças para fins de efeito demonstrativo e de convencimento sobre a necessidade de se reter crianças em veículos automotores. Trata-se de um trenó, guiado, que se desloca sobre trilhos sendo tracionado por cabo de aço e, capaz de, sem dano permanente, colidir contra uma barreira de impacto deformável. O equipamento foi concebido para fácil instalação em locais públicos e utiliza motor de indução para tracionar o cabo de aço e sistemas de automatização de aferição da velocidade, de aceleração e parada do motor. A instrumentação eletrônica utilizada na montagem do simulador permite avaliação do desempenho do equipamento para velocidades de até 20 Km/h / Abstract: Design, construction and evaluation of impact tests simulator performance of child restraint systems. The constructive solution aimed to simulate an automobile collision and uses dummies representing children for the purposes of demonstration effect and conviction about the need to retain children in motor vehicles. This is a sled, guided, moving on rails being pulled by steel cable and capable of, without permanent damage, crash into a deformable barrier impact. The equipment is designed for easy installation in public places and induction motor uses to pull the cable and speed measurement automation systems, acceleration and engine stop. The electronic instrumentation used in the simulator assembly allows assessment of equipment performance for speeds up to 20 km / h / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
15

Investigation of Pediatric Seat Belt Fit on Belt-Positioning Booster Seats (BPBs) and the Implications for Belt Interaction and Dynamic Outcomes during Motor Vehicle Crashes

Baker, Gretchen Hess 12 September 2022 (has links)
No description available.
16

Effect of Lap Belt Position on Kinematics & Injuries by using 6YO PIPER child HBM : in Frontal Crash Simulations / Höftbältets påverkan på kinematiken och skador genom att använda 6åriga PIPER barnhumanmodellen vid frontalkrock

El-Mobader, Sarah Hassan January 2018 (has links)
Traffic accidents are the second leading cause of child fatality among children younger than 15 years of age. In the course of 10 years, the implementation of child restraint systems has decreased child fatality in traffic accidents with 50%, for children younger than 15 years. To gain an understanding of the kinematics and injury mechanisms of children in cars, finite element based human body models, representing higher biofidelity compared to crash test dummies, are developed. An FP7 European project, PIPER, developed a child HBM with an associated framework for scaling, morphing and positioning. The PIPER child HBM is scalable between the ages of 1.5-6YO, with scalable anthropometrics. This makes the PIPER child HBM, a powerful tool for analyzing children in vehicles.  There are insufficient analyses conducted with the PIPER child HBM, due to its recent release. The purpose is thus to study the robustness of the HBM and its sensitivity to variation of lap belts by conducting a parametric study. Injury analysis and its sensitivity to lap belt variations were in addition studied in terms of kinematics by the study of submarining, the pelvic interaction with the lap belt, and the study of injuries related to the skull, brain, kidneys and liver. A full frontal crash simulation of a 6YO PIPER child HBM, with anthropometrics, covering the 50th percentile, have been investigated. The 6YO PIPER child HBM was seated with no booster, Volvo booster cushion and Volvo highback booster, with variations of the lap belt. The hip interactions and the submarining response of the 6YO PIPER child HBM were studied, by the study of the lap belt interactions with the pelvis and abdominal organs. The abdominal organs were related to the liver and kidneys, and compared to published threshold values.  This study showed that the overall robustness of the model was questionable. With respect to kinematics, the model indicated higher robustness, however, when conducted the crash simulations with the 6YO PIPER child HBM, it was concluded that the robustness was low due to repeated premature terminations. The 6YO PIPER child HBM revealed repeated errors such as, mesh distortions, negative volume and shooting nodes. When studying the sensitivity of the 6YO PIPER child HBM, when varying the lap belt angles, as well as changing the type of boosters in addition to vehicle anchorage positions, it could be seen that the 6YO PIPER child HBM was able to capture variations with respect to lap belt positioning. Hence, the model seems to be capable of providing relevant information regarding sensitivity for lap belt variations from the kinematic perspective, in terms of being able to capture kinematic o↵set, submarining and pelvis interaction with the lap belt. However, with respect to predicted abdominal injuries and head injuries, the sensitivity was not as distinct. Some limitations were observed in which the 6YO PIPER child HBM indicated unrealistic predicted injuries related to the head, which was associated with excessive movement of the 6YO PIPER child HBM. / Trafikolyckor är den näst vanligaste orsaken till barndödlighet i världen bland barn yngre än 15 år. Inom loppet av 10 år har användning av bilbarnstolar i fordon minskat barndödligheten med 50% hos barn under 15 år. För att få en ökad förståelse om barn i bilar framtogs finita element humanmodeller som har en detaljerad anatomi samt responser liknande till människan. Ett FP7 finansierat europeiskt projekt, PIPER, skapade en barnhumanmodell med en tillhörande programvara som används för skalning, förvandling, och positionering av barnhumanmodellen. Humanmodellen är skalbar för åldrarna 1.5 år upp till 6 år, med olika antropometriska värden. Detta gör att PIPER barnhumanmodellen är ett kraftfullt verktyg att använda sig av för att studera barn i bilar. Då PIPER barnhumanmodell lanserades nyligen, finns det i dagsläget bristfällig information om humanmodellen och programmet. Syftet var därmed att undersöka hur robust modellen var samt hur dess känslighet var mot variationer av höftbältet genom en parameterstudie. Skadors känslighet studerades dessutom mot variationer av höftbältet genom att studera kinematiken i form av underglidning och höftens interaktion med höftbältet. Dessutom studerades känsligheten på skador relaterade till skallen, levern och njurarna. I denna studie har en frontalkrock med en 6 årig PIPER barnhumanmodell med antropometriska värden, som innefattar 50:e percentilen, undersökts. Den 6åriga PIPER barnhumanmodellen var placerad utan bilbarnstol, på en Volvo bälteskudde och på en Volvo bältesstol, där höftbältet sedan varierades. Höftens interaktion och PIPER barnhumanmodellens respons för variationer i höftbälte studerades. Interaktionerna med höften och bukorganen var relaterade till skador på levern och njurarna genom att jämföra med publicerad data. Denna studie påvisade att den generella robustheten av modellen kunde ifrågasättas. Modellen hade ändock högre robusthet med hänsyn på kinematiken, men på grund av de upprepande felen vid simuleringarna, kunde man konstatera att robustheten på den 6åriga PIPER barnhumanmodellen var låg. När höftbältet varierades, både när bilbarnstol varierades såväl som vinkel på höftbälte, kunde man konstatera att den 6åriga PIPER barnhumanmodellen kunde fånga skillnaderna med hänsyn på höftbältets vinkel. Modellen var dessutom kapabel till att fånga känsligheten från det kinematiska perspektivet i form av kinematisk förskjutning, underglidningen samt höftens interaktion med höftbältet. Modellen påvisade däremot ingen distinkt känslighet med hänsyn på skador relaterade till bukorganen samt huvudet. Några begränsningar observerades där den 6åriga PIPER barnhumanmodellen indikerade orealistiska skador på huvudet, som var relaterade till modellens överrörlighet. / FFI, Assessment of Passenger Safety in Future Cars
17

Influence of retraint systems during an automobile crash : prediction of injuries for frontal impact sled tests based on biomechanical data mining / Infkuence des systèmes de retenue lors d'un accident automobile : Prédiction des blessures de l'occupant lors d'essais catapultés frontaux basées sur le data mining

Cridelich, Carine caroline 17 December 2015 (has links)
La sécurité automobile est l’une des principales considérations lors de l’achat d’un véhicule. Avant d’ être commercialisée, une voiture doit répondre aux normes de sécurité du pays, ce qui conduit au développement de systèmes de retenue tels que les airbags et ceintures de sécurité. De plus, des ratings comme EURO NCAP et US NCAP permettent d’évaluer de manière indépendante la sécurité de la voiture. Des essais catapultes sont entre autres effectués pour confirmer le niveau de protection du véhicule et les résultats sont généralement basés sur des valeurs de référence des dommages corporels dérivés de paramètres physiques mesurés dans les mannequins.Cette thèse doctorale présente une approche pour le traitement des données d’entrée (c’est-à-dire des paramètres des systèmes de retenue définis par des experts) suivie d’une classification des essais catapultes frontaux selon ces mêmes paramètres. L’étude est uniquement basée sur les données du passager, les données collectées pour le conducteur n’ étant pas assez complètes pour produire des résultats satisfaisants. L’objectif principal est de créer un modèle qui définit l’influence des paramètres d’entrées sur la sévérité des dommages et qui aide les ingénieurs à avoir un ordre de grandeur des résultats des essais catapultes selon la législation ou le rating choisi. Les valeurs biomécaniques du mannequin (outputs du modèle) ont été regroupées en clusters dans le but de définir des niveaux de dommages corporels. Le modèle ainsi que les différents algorithmes ont été implémentés dans un programme pour une meilleur utilisation quotidienne. / Safety is one of the most important considerations when buying a new car. The car has to achievecrash tests defined by the legislation before being selling in a country, what drives to the developmentof safety systems such as airbags and seat belts. Additionally, ratings like EURO NCAP and US NCAPenable to provide an independent evaluation of the car safety. Frontal sled tests are thus carried outto confirm the protection level of the vehicle and the results are mainly based on injury assessmentreference values derived from physical parameters measured in dummies.This doctoral thesis presents an approach for the treatment of the input data (i.e. parameters ofthe restraint systems defined by experts) followed by a classification of frontal sled tests accordingto those parameters. The study is only based on data from the passenger side, the collected datafor the driver were not enough completed to produce satisfying results. The main objective is tocreate a model that evaluates the input parameters’ influence on the injury severity and helps theengineers having a prediction of the sled tests results according to the chosen legislation or rating.The dummy biomechanical values (outputs of the model) have been regrouped into clusters in orderto define injuries groups. The model and various algorithms have been implemented in a GraphicalUser Interface for a better practical daily use.
18

Occupant restraint modeling: Seat belt design

Patlu, Srikanth January 2001 (has links)
No description available.

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