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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.
1

Evaluation of hot gas welding techniques for the joining and repair of polymeric bumper materials

Turner, Brian Edward January 1990 (has links)
No description available.
2

Reading bumper stickers critcally: a teaching and research project with Grade 12 students at Randfontein secondary school

Sibanda, Rockie 13 March 2009 (has links)
ABSTRACT This study mainly sets to explore how English second language students grade 12 learners at Randfontein Secondary School develop critical literacy awareness (CLA) by reading ‘bumper’ stickers found in mini-bus taxis commonly known as taxis. Data used in this project was mainly collected through interviews with research participants namely; students, taxi drivers, bumper sticker manufacturers and taxi commuters. The teacher/researcher required students to collect literary texts from their environment for use in their critical literacy class. This research project mainly employs Fairclough’s Critical Discourse Analysis model as an analytical model, which holds that CDA should include the socio-cultural contexts in which texts are produced and read. Data was analysed by all the students in class, especially the six students who were selected for the focus group. The researcher (myself) analysed the students’ reading of texts so as to establish the extent to which they were developing critical literacy awareness. The research found that my students resisted bumper stickers as a discourse that differed from their own ideological positions. Data in this study reveals that the students approached the bumper stickers from a position of estrangement because they were reading from an urban social context that differs from the taxi drivers’ rural social context. This study showed that getting students to be researcher themselves can be a very fruitful and developmental learning experience.
3

Status symbols in triathlete culture

Unknown Date (has links)
Triathlon status symbols allow community members to gain prestige. The accrual of paraphernalia, such as race apparel and bumper stickers, provide individuals with a means to display their accomplishments for non-participants, too. Ethnographic fieldwork, questionnaires and interviews provided insight into a variety of experiences. The individual nature of the sport is reflected by a participant's decision to display status markers. Car signs (e.g., bumper stickers and license plate frames) are displayed by a quarter of race participants. They come in a variety of forms allowing the car's driver to communicate with triathletes and non-triathletes while driving on the road. The most prestigious triathlon is the Ironman. The M Dot Ironman logo appears as a decal on vehicles and as a mark of permanence on the body. Tattoos act as a formal communication system in a similar manner to car signs. Triathletes display status symbols to garner respect from their peers and separate themselves from the larger society. / by Adam Slotnick. / Thesis (M.A.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
4

Effects of rear bumper beam deletion on the perception of steering performance of commercial vehicles

Banks, Alan James January 2015 (has links)
In order to remain competitive in the marketplace, all motor vehicle manufacturers face difficult decisions with regard to balancing cost vs. feature. That is to say that the manufacturer must balance the cost of the product to the customer to remain competitive whilst offering appropriate technology and standard features required by that customer. All motor manufacturers are therefore under pressure to keep costs of nonfeature items to a minimum. One of the cost reductions items prevalent on most vehicles is the deletion of the structural member that attaches the rear bumper, known as the bumper beam (RBB), which is researched in this Thesis. This generates average vehicle savings of $20 and, as this is invisible to the customer, should enable the manufacturers to realise a significant saving or allow this revenue to be spent on additional feature without loss of vehicle function. However, in nearly all cases, deletion of the rear bumper beam has the effect of degrading the steering responses of the vehicle by 1 to 1½ rating points (out of 10), which is contrary to the premise of cost reductions; which is to ensure that vehicle function is unaffected. Initial analysis of vehicles with deleted rear bumper beams cannot show an objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the effects of the bumper beam. It was necessary to employ unconventional modelling and testing methods such as rigid body, flexible body model techniques as well as experimental studies included driving robots and expert driver appraisals. The research demonstrated that vehicle modelling methods currently used, cannot establish or predict the complete vehicle ride and handling status. A total vehicle model approach should be used without separating the body CAE model and vehicle dynamics ADAMS model into separate entities. Furthermore, it was concluded that the determination to the effects of body hysteresis rather than pure stiffness is of crucial importance and that the steering attribute could be maintained with the deletion of the RBB analytically.
5

Sex avancerade sekunder : Berättandet i bumper-ads på sociala medier

Eriksson, Emil, Johansson, Adam January 2023 (has links)
Reklamfilmer blir alltmer anpassade för sociala medier och formatet för nätbaserad reklam har således krympt till endast sex sekunder. Denna studie vill undersöka hur det går att applicera en avancerad berättelsestruktur under dessa sex sekunder och vilka känslor som reklamen försöker väcka hos betraktaren. Denna studie analyserar fyra reklamfilmer från olika produktgrupper för att göra analyserna mer djupgående. Filmerna är inte från samma kategori för att få större variation och täcka en större del av fältet. Studien kommer utgå från Joseph Campbells modell på 17 steg och undersöka vilka steg som syns och vilka som bortfaller/sammankopplas. Utöver att ta reda på vilka steg som finns har studien även fokus på vilka känslor som reklamfilmerna försöker framhäva. Studierna visar att det går att applicera en avancerad berättarstruktur på en bumper-ad på endast sex sekunder, med stor variation av känslostimulans.
6

Effects of Rear Bumper Beam Deletion on the Perception of Steering Performance of Commercial Vehicles

Banks, Alan J. January 2015 (has links)
In order to remain competitive in the marketplace, all motor vehicle manufacturers face difficult decisions with regard to balancing cost vs. feature. That is to say that the manufacturer must balance the cost of the product to the customer to remain competitive whilst offering appropriate technology and standard features required by that customer. All motor manufacturers are therefore under pressure to keep costs of nonfeature items to a minimum. One of the cost reductions items prevalent on most vehicles is the deletion of the structural member that attaches the rear bumper, known as the bumper beam (RBB), which is researched in this Thesis. This generates average vehicle savings of $20 and, as this is invisible to the customer, should enable the manufacturers to realise a significant saving or allow this revenue to be spent on additional feature without loss of vehicle function. However, in nearly all cases, deletion of the rear bumper beam has the effect of degrading the steering responses of the vehicle by 1 to 1½ rating points (out of 10), which is contrary to the premise of cost reductions; which is to ensure that vehicle function is unaffected. Initial analysis of vehicles with deleted rear bumper beams cannot show an objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the effects of the bumper beam. It was necessary to employ unconventional modelling and testing methods such as rigid body, flexible body model techniques as well as experimental studies included driving robots and expert driver appraisals. The research demonstrated that vehicle modelling methods currently used, cannot establish or predict the complete vehicle ride and handling status. A total vehicle model approach should be used without separating the body CAE model and vehicle dynamics ADAMS model into separate entities. Furthermore, it was concluded that the determination to the effects of body hysteresis rather than pure stiffness is of crucial importance and that the steering attribute could be maintained with the deletion of the RBB analytically.
7

Modelos de falha em análise numérica de estrutura veicular submetida a impacto de baixa velocidade. / Numerical simulations and experiments of vehicle structures under low speed crash loadings to evaluate fracture models.

Bugelli, Eduardo Barjud 26 March 2010 (has links)
O presente trabalho visa o estudo e avaliação de diversos modelos de falha através de ensaios experimentais e análises numéricas. A caracterização do material foi feita por meio de ensaios de tração de espécimes com e sem entalhe e de cisalhamento, para prover dados em uma ampla faixa de triaxialidade. A calibração dos parâmetros necessários para cada modelo de falha ocorreu através da obtenção das componentes de tensões e de deformações na região de ruptura, obtidas por meio de análises numéricas destes ensaios. O critério da máxima deformação plástica equivalente, modelo de dano de Johnson-Cook e critério da máxima tensão cisalhante foram aplicados em um caso de impacto em pára-choque. Diversos ensaios de impacto foram realizados até a que se atingisse a ruptura satisfatória do componente. Os ensaios foram modelados em elementos finitos, através do programa comercial LS-Dyna®, sendo que os modelos de falha calibrados foram aplicados para o ensaio onde se ocorreu ruptura. Houve boa concordância entre os resultados obtidos numericamente e experimentalmente, respeitadas as observações realizadas acerca da especificidade deste caso de impacto em baixa velocidade. / The aim of the present work is an assessment of several fracture models through experiments and numerical simulations. Tensile tests with notched and unnotched specimens were carried out to provide the material characterization in a wide range of stress triaxiality. The calibration of the parameters required by the fracture models was enabled by the parallel numerical simulation of the tensile tests, providing information on the stress and strain components at the failure locus. The constant equivalent strain criterion, the Johnson-Cook failure model and the maximum shear stress failure criterion were applied in a bumper beam impact case study. Several low speed impact tests were carried out in order to result in the components rupture. Numerical simulation of the experiments was performed using commercial finite element code LS-Dyna®. Good correlation of experiments and numerical simulations was achieved when considering this particular low speed case study.
8

Modelos de falha em análise numérica de estrutura veicular submetida a impacto de baixa velocidade. / Numerical simulations and experiments of vehicle structures under low speed crash loadings to evaluate fracture models.

Eduardo Barjud Bugelli 26 March 2010 (has links)
O presente trabalho visa o estudo e avaliação de diversos modelos de falha através de ensaios experimentais e análises numéricas. A caracterização do material foi feita por meio de ensaios de tração de espécimes com e sem entalhe e de cisalhamento, para prover dados em uma ampla faixa de triaxialidade. A calibração dos parâmetros necessários para cada modelo de falha ocorreu através da obtenção das componentes de tensões e de deformações na região de ruptura, obtidas por meio de análises numéricas destes ensaios. O critério da máxima deformação plástica equivalente, modelo de dano de Johnson-Cook e critério da máxima tensão cisalhante foram aplicados em um caso de impacto em pára-choque. Diversos ensaios de impacto foram realizados até a que se atingisse a ruptura satisfatória do componente. Os ensaios foram modelados em elementos finitos, através do programa comercial LS-Dyna®, sendo que os modelos de falha calibrados foram aplicados para o ensaio onde se ocorreu ruptura. Houve boa concordância entre os resultados obtidos numericamente e experimentalmente, respeitadas as observações realizadas acerca da especificidade deste caso de impacto em baixa velocidade. / The aim of the present work is an assessment of several fracture models through experiments and numerical simulations. Tensile tests with notched and unnotched specimens were carried out to provide the material characterization in a wide range of stress triaxiality. The calibration of the parameters required by the fracture models was enabled by the parallel numerical simulation of the tensile tests, providing information on the stress and strain components at the failure locus. The constant equivalent strain criterion, the Johnson-Cook failure model and the maximum shear stress failure criterion were applied in a bumper beam impact case study. Several low speed impact tests were carried out in order to result in the components rupture. Numerical simulation of the experiments was performed using commercial finite element code LS-Dyna®. Good correlation of experiments and numerical simulations was achieved when considering this particular low speed case study.
9

Studie vlivu parametrů modelu na simulaci pojišťovacího nárazu vozidla / Study of Model Parameters Influence on Vehicle Insurance Impact

Šandera, Petr January 2009 (has links)
The diploma thesis deals with basic test procedures conducted by companies Euro NCAP and RCAR. It focuses mainly on insurance impact and describes the creation of a model, simulation and crash on barrier. Moreover, it explores the influence of change of yield strength, thickness and hardening of material of energy-absorber on simulation of insurance impact, especially the amount of absorbed energy by energy-absorber.
10

Hnací ústrojí nekonvenčního vidlicového vznětového šestiválce s pryžovým tlumičem / Powertrain of unconvential V-6 diesel engine with rubber damper

Bečka, Petr January 2011 (has links)
The aim of this work is to design the crankshaft fork unconventional six-cylinder with offset pivots, the torque balance, modal analysis, vibration analysis of torsional and torsional vibration damper design, stress analysis using FEM.

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