No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24815号 / 工博第5158号 / 新制||工||1985(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 渦岡 良介, 准教授 岩井 裕正, 准教授 上田 恭平, 教授 森 信人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

No description available.

Airbags are a passive safety technology, required to function with zero failure rate. Advances in Computer Aided Engineering have allowed vehicle manufacturers to predict material and system behavior in the event of a crash. The sudden and rapid nature of a vehicle frontal crash, together with strict requirements put on safety make this a sensitive task. This thesis focuses on the front passenger airbag deployment and the instrument panel’s response. Various airbag modelling techniques are studied and presented in this document. This work is part of a larger-scale attempt to model a generic-sled that is physically representative of a real vehicle. Various component tests are to be performed in the sled environment, as opposed to a real vehicle, to save costs. Various modules are added to the sled once their behavior is verified by testing and in simulations. Software are advanced enough to identify location and magnitude of stress concentrations that develop during crash. LS-DYNA is used for explicit finite element simulations of the instrument panel (IP) in question with different airbag models. Verification has been achieved by design of experiment (DOE); with tests conducted to capture both the movements of the airbag housing and IP movements in response. These movements are broken down in various phases, facilitating implementation in the sled environment. Simplifications are made both to the computer models as well as the physical testing environment. The effects of these simplifications are quantified and discussed. Theoretical background is provided where fit while assumptions are justified wherever made. DYNAmore recommendations regarding costeffective calculations as well as result verification are followed. The obtained results show that the FE models replicate the real event with acceptable precision. The findings in this work can, by minor tweaks, be implemented on other IP models in the Volvo Cars range, leading to cost-saving solutions. This thesis provides the necessary information for sled implementations as well as future improvement suggestions. / Krockkudde är en s.k. passiv säkerhetsteknik som krävs att fungera felfritt. Framsteg inom Computer Aided Engineering har tillåtit biltillverkare att förutsäga material och systembeteende i samband med krock. Den plötsliga karaktären av krock, tillsammans med höga säkerhetskrav, gör detta till en känslig uppgift. Denna avhandling fokuserar på passagerarsidans krockkudde och instrumentbrädans (IP) respons under uppblåsning. Olika metoder för modellering av krockkuddar har studerats och presenteras i detta dokument. Arbetet är en del av en större skala försök att modellera en generisk-släde som är fysiskt representativ av en riktig bil; där olika komponent-tester skall utföras för att minska kostnader. När olika modulers beteende verifieras läggs de till släden. Denna verifiering sker genom finita element (FE) simuleringar så väl som fysiska tester. FE mjukvara är idag tillräckligt avancerad för att identifiera samt visualisera spänningskoncentrationer som uppstår i en konstruktion vid krock. LS-DYNA används i detta arbete för explicita FE simuleringar av en Volvo XC90 IP, lastad med olika krockkudde-modeller. Modell verifiering har uppnåtts genom försöksplanering (DOE); med tester utförda för att fånga rörelser av IP så väl som krockkudde-behållaren. Dessa rörelser är sedan uppdelade i olika faser för enklare genomförande i släde miljön. Förenklingar och antaganden görs både till FE modeller och fysiska testmiljön. Effekter av dessa har kvantifierats och relevant teoretisk bakgrund har inkluderats. Dokumentet innehåller även diskussion kring val av mätutrustning samt förbättringsförslag för fortsatt arbete. DYNAmore rekommendationer gällande kostnadseffektiva beräkningar och verifiering av simulerings-resultat har följts. Under arbetet visade sig att FE modellerna kan återskapa händelsen med hög noggrannhet; dessa trotts svårigheter i modellering av plast material. Möjligtvis kan man, genom mindre modifieringar, relatera slutsatserna i detta arbete till olika IP modeller i företagets produktkatalog vilket förmodligen leder till ytterligare kostnadsbesparingar. Denna avhandling ger den information som behövs för genomföranden i den generiska miljön.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The protests and strikes in Västervik 1917 have been considered to be the start of the hunger movement in Sweden. The events have been called the Swedish revolution. The Swedes who participated were inspired by the February revolution in Russia, and there were similarities, but the reformist side won and the outcome was the equal vote for most men and women. This essay analyzes the way four newspapers report from the events in relation to the political orientation of the newspapers, the involvement of women in the strikes and protests, and how the events in Västervik can be used for educational purposes. The two right wing newspapers wrote negatively about the worker´s movement and, the two left wing newspapers published articles that acknowledged the struggle of the workers and the abuse against the workers by the factory owners. Three of the newspapers (Smålands Allehanda, Smålands Folkblad and Västerviks Veckoblad) initially have relatively neutral articles and the comments about the opposing political side are relatively subtle. The revolutionary syndicalist newspaper Syndikalisten has a more aggressive tone because it functions as the official paper of SAC, the Swedish workers central organization. The inquiry shows that women were not that much involved in the strikes and protests in Västervik. They were active in the certain sectors, such as foodstuff, where they, in certain cases, could make a big difference. The events in Västervik 1917 can be used in school when the students work with the history of their local communities in a social learning environment.

When dealing with the separation of materials, the metal shearing process such as punching, is widely used in theindustry due to its time efficient manner. There is however, a need to better understand the process in order toimprove quality of the final product. Working with numerical simulations of themetal shearing process, there aretwo major difficulties. One being the extremely large deformation, the other being material failure. The combinationof these two makes numerical modeling challenging and is the reason for this study.The problem was divided in to two main parts, one where material modeling was studied, the other part focusedon numerical modeling and experiments of the punching process. A material model considering both plasticityandmaterial failure was created for a boron steel material. Plasticity behavior of thematerial was modeled with anelasto-plastic model and a calibratedModifiedMohr-Coulomb (MMC) failure criterion to model the material failure.The resultingMMC-model agreed well with the experiments.Punching experiments with varying clearances were performed on the boron steel. Punch forces and displacementswere continuously sampled throughout the process, and after the punching experiments were finished the punchededge profiles were studied. The multiphysics simulation software LS-DYNA was then utilized, and three dimensionalsimulations of the punching process using the Smoothed Particle Galerkin (SPG)method were performed.Results from the SPG-simulation corresponded very well with the results from punching experiments, and it can beconcluded that the model was able to capture the material behavior of the sheet in a highly detailed level. When thepunched edge profiles from the simulations were compared to the experiments, there was an almost exact match forall the cases studied. The force-displacement behavior of the punch from simulations was in great consistency withexperimental results as well.Itwas also concluded that the combination of a stress state dependent failure criterion together with the SPG-methodshows significant possibilities to cope with three dimensional problems where large deformations in combinationwith difficultmaterial failure occurs. This study focuses on the punching process, but the generality of this novelmodeling technique can be applied to many industrial cases and is a step towards a better and more reliablemodeling of failure in combination with extremely large deformation.

La presente ricerca intende indagare alcune tendenze interazionali di discenti giapponesi e svedesi in relazione alla cultura dei parlanti e al processo comunicativo che ha luogo nell’insegnamento dell’italiano all’estero. Gli stili comunicativi e gli stili di apprendimento costituiscono lo sfondo della dinamica di rapporto fra docente e studente. Tali elementi si manifestano in interazioni interculturali attraverso una co-occorrenza di regolarità caratteristiche della comunità linguistica a cui i discenti appartengono. Osservando lo stile comunicativo degli studenti si nota che alcune strategie interazionali riflettono valori culturali a cui è legato il senso della politeness, così come percepito dalla loro comunità linguistica. Il trasferimento di strategie comunicative da una lingua all’altra può dare origine a dissonanze nelle interazioni tra docenti e studenti, inficiando il processo comunicativo che permette di attuare pragmaticamente l’azione didattica, compromettendone talvolta il buon esito. Le modalità interazionali degli studenti riflettono lo stile comunicativo della comunità linguistica di cui fanno parte, mentre la tradizione della didattica delle lingue straniere permette di comprendere gli stili di apprendimento dei discenti. Si comprende così la centralità che hanno la cultura dei parlanti e il processo comunicativo, ai fini dell’insegnamento e dell’apprendimento delle lingue all’estero. / The aim of the present research is to investigate some interactional features of Japanese and Swedish students as regards the culture of the speakers and the process of communication involved in the teaching of Italian as a foreign language. Communication styles and learning styles form the background of the dynamics in the relationship between the lecturer and the student. Such elements can be perceived in intercultural communications, especially by a co-occurrence of regularities that are distinctive of the language community the students belong to. By observing the communication styles of the students one can see that some interactional strategies reflect cultural values that are strictly connected to the sense of politeness, as perceived by a language community. Transferring communicative strategies from one language to another can produce dissonances in the interactions between the lecturer and the students; this in turn can affect the process of communication in its pragmatic application of the teaching, at times making it less successful. The communication styles of the students reflect those of the language community they belong to, whereas the foreign language teaching tradition allows one to comprehend their styles of learning. Thus one can rediscover the central role of culture and communication in the process of teaching a foreign language abroad.

No description available.