No description available.

The AISI (1996) Specification for the Design of Cold-Formed Steel Structural Members provisions for web-crippling are believed to be conservative for multi-web deck sections. They are based on unfastened specimens and are limited to the use of decks with certain geometric parameters. The unified web crippling equation of the North American (2002) Specification for the Design of Cold-Formed Steel Structural Members (adopted from Canadian S136-94 Specification) is also limited to certain geometric parameters. Although it has new web crippling coefficients for different load cases and different end conditions, in the End One Flange (EOF) loading case, coefficients for the unfastened configuration were used as a conservative solution for the fastened case because there was no directly applicable test data available in the literature. This thesis presents the results of an experimental study on web-crippling strength of multiple-web cold-formed steel deck sections subjected to End One Flange (EOF) loading. Seventy-eight tests were conducted at Virginia Tech. Test specimens lying inside and outside of certain geometric parameters of the specifications were tested with both unrestrained and restrained end conditions. Test specimens lying inside the specification parameters have revealed conservative results in the prediction of web crippling capacity using both AISI (1996) and North American (2002) equations. Using the unified web-crippling equation of North American Specification, a nonlinear regression analysis was performed to update the unfastened case coefficients and derive new fastened case coefficients. Also, the calibration of these coefficients is done for both Canadian S136 (1994) and AISI (1996) specifications. / Master of Science

No description available.

The objection of this dissertation is to examine effects of stowed cargo on safety driving of a vehicle. Based on general experience of weighing trucks and monitoring of cargo fixture, my attempt was to summarize related legislative conditions of the operation of trucks in terms of payload, weighing and stowing of cargo. In the first part I worked on consistent methodology of stowing and fastening of cargo on trucks. I've included various methods of loading cargo and different ways of fastening and their calculations. The main body of the second part is a practical methodology of inspectional weighing of trucks on the road. In this section I took into account the current method and procedure of inspectional weighing and measuring of trucks. During my trial weighing of different types of trucks I proved that the key factor for safe seating and lashing of load on a vehicle is determining center of gravity of the vehicle. I solve this problem in detail in the last part of my work.

Urbanisation has historically led to issues with property damage and sickness, due to pests such as rats. Traditionally, rats have been exterminated using poison and manually loaded traps. As of late however, more effective and humane means of control have been developed, such as automatic and connected traps. As rats use the sewer system as we use the highway, connecting properties together, it is natural to place traps there. Nomor, a service company that performs pest control among other services, is interested in developing their own automatic mechanical sewer mounted trap for their own specific needs. In this thesis, the fastening mechanism and enclosure for such a trap are developed, with a concept developed in a previous collaboration used as a base. In this concept, a fastening mechanism is used to fasten the trap to the open pipes located in the sewer manholes. Rats passing underneath the trap are executed by the striking of a carbon dioxide driven cylinder. The enclosure surrounds the fastening mechanism and provides an interface between it and the executional unit, which is developed separately. The final prototype, which was made mostly using 3D-printing of PLA parts and some light metalwork, was tested and evaluated using a testing rig made from layered MDF pieces. The rig was constructed with an optimal scenario in mind, with dimensions like those in pipes which Nomor are likely to want to mount the trap in. The main use of the rig was to evaluate the dimensions and fastening abilities of the trap. Tests and analysis of the construction gave that the fastening mechanism and enclosure had potential to meet the requirements from Nomor in a reliable manner, if a more sophisticated method of mounting and a better mechanism for keeping the trap fastened was developed.

No description available.

Die Auswahl einer zweckmäßigen Verbindungstechnik hat großen Einfluss auf die Kosten für die Herstellung und Wartung von Gütern. Das mechanische Verbinden von Bauteilen mit Schließringbolzen gehört zum umformtechnischen Fügen. Damit werden kostengünstig unlösbare und mechanisch hoch beanspruchbare, punktförmige Verbindungen erzeugt. Die vorliegende Arbeit hatte das Ziel, in umfassender Form den Nachweis zu erbringen, dass mit Schließringbolzensystemen ohne Sollbruchstelle wartungsfreie Verbindungen hergestellt werden können. Diese Wartungsfreiheit bezieht sich auf den Erhalt der mechanischen Eigenschaften der Verbindung und des Korrosionsschutzes bis zur beabsichtigten Grenznutzungsdauer. Aus einer Analyse des Standes der Technik wurde der Forschungsbedarf hinsichtlich der Wartungsfreiheit von Schließringbolzenverbindungen aus mechanischer und korrosiver Sicht abgeleitet. In einem mehrstufigen Prüfprogramm, unterteilt nach Anwendungen im Nutzfahrzeugbau und Stahlbau, wurde nach maschinenbaulichen und stahlbaulichen Konzepten die mechanische Leistungsfähigkeit der Verbindungen untersucht. Die Forschungsergebnisse aus diesem Programm und der Test neu entwickelter Beschichtungssysteme für die Bolzen und die Schließringe bestätigten die Eingangsthese über die Wartungsfreiheit. Metallografische Analysen und FEM Rechnungen ergänzen die Arbeit. Sie ist in sechs Abschnitte unterteilt und enthält 135 Abbildungen, 25 Tabellen, 3 Anlagen. Es wurden 118 Literaturquellen berücksichtigt. Mit der Arbeit steht dem Ingenieur ein umfangreiches Auskunftsmaterial zum Vergleich von Schließringbolzenverbindungen mit anderen Fügeverfahren, besonders jedoch zur Verschraubung zur Verfügung. Die durchgeführten Untersuchungen und Aussagen sollten in zukünftiger Forschung zu einem ganzheitlichen Konzept für die rechnerische Auslegung und Dimensionierung von Schließringbolzenverbindungen nach dem Vorbild der VDI 2230 und der EN 1993 weitergeführt werden.

Made available in DSpace on 2016-07-27T13:52:18Z (GMT). No. of bitstreams: 1 Vania Hanum.pdf: 1923336 bytes, checksum: 5f3f7a65ff5bdea570ac7803f105ae8e (MD5) Previous issue date: 2010-05-30 / This study approaches the implantation aspects of the Fastening Learning Program in the city of Rio Verde (GO), especially in relation to proposed pedagogical goals and the reached results. This Program began in 1997, by an initiative of the Brazilian Education Ministry, aiming to implant organizational, curricular and pedagogical measures to correct distortions in the scholar float of 5th and 6th year students from Elementary School. The Program done in Rio Verde came from a project planned by the Center of Studies and Researches in Education, Culture and Communitary Action (Cenpec), which consisted on serving these students in Fastening classes in a two-year period. The goal of the research was to verify the effectiveness of the goals done of this project, which one, although it seemed political and pedagogical suitable, showed signs that it was not reaching its goals, in face of the difficulties in organizing the teaching contents and methodology, the students were distant in relation to proposal, the not appropriate evaluation practices, and others. The interest in analyzing the proposal was to check if students from Fastening classes and established again to the regular teaching showed compatible performance in relation to other students, if they were attending classes or, because of other reasons, have quit school. To do this research were used as procedures: analysis of official documents and interviews with students, school leaders and teachers. The data analyses shows a considerable distance between the proclaimed goals and the done ones, showing to the responsible for the direction of this Program the need of rethinking their goals and pedagogical and didactic procedures. / Este estudo aborda aspectos da implantação do Programa de Aceleração da Aprendizagem na cidade de Rio Verde (GO), especialmente em relação aos objetivos pedagógicos propostos e aos resultados alcançados. Esse Programa foi iniciado em 1997, por iniciativa do Ministério da Educação do Brasil, com a finalidade de implantar medidas organizacionais, curriculares e pedagógicas para correção das distorções do fluxo escolar de alunos de 5ª a 6ª séries do Ensino Fundamental. O Programa realizado em Rio Verde decorreu de projeto elaborado pelo Centro de Estudos e Pesquisas em Educação, Cultura e Ação Comunitária (Cenpec), que consistia em atender esses alunos em classes de Aceleração num período de dois anos. A finalidade da pesquisa foi verificar a efetividade da realização dos objetivos desse projeto o qual, por mais que parecesse ser política e pedagogicamente adequado, apresentava sinais de que não estava atingindo seus objetivos, tais como as dificuldades na organização dos conteúdos e metodologia de ensino, o distanciamento dos alunos em relação à proposta, a inadequação das práticas de avaliação, entre outros. O interesse em analisar a proposta foi verificar se os alunos egressos das classes de Aceleração e reintegrados ao ensino regular apresentavam desempenho compatível ao dos demais alunos, se continuavam freqüentando as aulas ou se, por um ou outro motivo, haviam abandonado a escola. Para a realização da pesquisa foram utilizados como procedimentos: análise de documentos oficiais e entrevistas com alunos, dirigentes escolares e professores. A análise dos dados mostrou um considerável distanciamento entre os objetivos proclamados e os realizados, levando a indicar aos responsáveis pela gestão desse Programa a necessidade de repensar seus objetivos e seus procedimentos pedagógico-didáticos.

This report discusses different steps of the product development of a new tool belt, for the company Husqvarna Group, to be used by professional forestry workers. From identifying the customers’ needs through field studies and inter-views with different users, to a substantial solution to the problem. The introduction states the purpose of the report, the research questions that this report is discussing, and also the delimitations that have been made. The report is focused on finding a new and better solution than the current one to attaching holsters on the tool belt, but also how detachable braces can be attached to the belt. Husqvarna and their current tool belt, is covered along with the main com-petitors’ tool belts. Then follows a chapter with theoretical background there the QFD method and Pugh’s decision matrix are described which are later used in the report. There is also a description of how the work in the forest is being done and how the tool belt is used. In the method chapter a time plan is established for the project’s different phases. After that the QFD method is used along with a house of quality to identify the customers’ needs and to rank the customers’ requirements and create engineering specifications to make the requirements measureable. The house of quality in-cludes an analysis of the competitors compared to the current tool belt from Husqvarna. A number of different concepts are included to solve the two prob-lems, fastener for holsters and braces are produced and are evaluated against the set requirements with the help of Pugh’s decision matrix. A “proof of concept” prototype is then produced from the final concept. A summary of the opportunities for improvements on the current tool belt is dis-played in the result chapter. There is a presentation of the final concept and the corresponding prototype. The concept for attaching the holsters includes a plastic band with holes that is attached in its lower edge so it can be folded down. Behind the plastic band, and through the holes, flies from the holsters are threaded. The plastic band and the holster flies is then covered and secured by a fabric band that is sewn onto the belt in the upper end and attached to the belt with snap fasteners in the lower end. Finally there is a chapter with conclusions, where the methods and the results are discussed and there are suggestions on how the work should be further continued. / Denna rapport behandlar olika steg inom produktframtagning av ett nytt verktygs-bälte för professionella skogsarbetare åt företaget Husqvarna Group. Från att identifiera kundens behov genom fältstudier samt intervjuer med olika användare, till en konkret lösning på problemet. Introduktionskapitlet klargör syftet med rapporten, de frågeställningar rapporten diskuterar och vilka avgränsningar som gjorts. Rapporten fokuserar på att hitta en ny och bättre lösning än den nuvarande för att fästa hölster på verktygsbältet och även hur avtagbara hängslen ska fästas i bältet. Företaget Husqvarna och deras nu-varande verktygsbälte och huvudkonkurrenternas bälten beskrivs. Sedan följer ett kapitel med teoretisk bakgrund där QFD-metoden och Pughs beslutsmetod besk-rivs som senare används i rapporten. En beskrivning av hur arbetet i skogen går till och hur verktygsbältet används finns också med. I kapitlet metod upprättas en tidsplan för projektets olika faser. Därefter används QFD-metoden och ett kvalitetshus för att identifiera kundens behov och för att få en rangordning av kundkraven samt skapa ingenjörsmässiga mätvärden på kraven. Kvalitetshuset innehåller även en konkurrensanalys där det nuvarande bältet jäm-förs med konkurrenternas. Ett antal olika koncept för att lösa de två problemen, fäste för hölster och hängslen, tas fram och utvärderas mot uppställda krav med hjälp av Pughs beslutsmatris. En “proof of concept” prototyp tas sedan fram av det valda konceptet. En sammanställning av förbättringsmöjligheterna på det nuvarande verktygsbältet läggs fram i kapitlet resultat. Där presenteras det slutliga konceptet och prototypen av det. Konceptet för att fästa hölstren är ett hålat plastband som fästs på bältet i underkanten av plastbandet så att det kan vikas ner. Bakom plastbandet och ge-nom hålet träs flärpar från hölstret, det hela täcks och säkras med ett textilband som är fastsytt i överkant och med tryckknappar i underkant. Avslutningsvis finns ett kapitel med slutsatser, där metoderna och resultaten dis-kuteras och där ges förslag på hur arbetet bör tas vidare.

Le besoin en isolation vibratoire des voies ferrées conduit de plus en plus souvent au recours à des systèmes d'attache de rail souples avec des designs sophistiqués. Par contre, les produits deviennent diversifiés mais leur conception se fait de manière empirique dans la pratique. Dans ce travail de thèse, deux systèmes d'attache de rail sont étudiés expérimentalement et numériquement: un système qui travaille principalement en cisaillement et l'autre en compression. Des essais quasi-statiques et dynamiques sont menés puis les résultats sont analysés à l'aide de différents modèles mécaniques. En plus, une série de tests sur les élastomères utilisés dans les deux systèmes sont réalisés. Ces tests permettent de choisir des modèles hyperélastiques et viscoélastique appropriés, et de déterminer les paramètres de propriétés mécaniques des élastomères dans ces modèles par des simulations Abaqus. En utilisant également Abaqus, des analyses par élément fini des deux systèmes d'attache sont effectués et les résultats sont comparés aux ceux des essais. Des non-linéarités d'origine matérielle et géométrique sont ainsi analysées et expliquées. Enfin, des études de sensibilité des paramètres sont effectuées, suivies d'études d'optimisation structurale. Cet étude devrait être utile pour une meilleure compréhension du comportement mécanique des systèmes d'attache de rail sous chargement statique et dynamique, et au final pour une meilleure pratique dans la conception et l'optimisation des produits / Higher demand on vibration isolation of track structure in modern railway track leads to a trend of lower stiffness of rail fastening systems, places an increasing need for better design approach as well. However the current development status of rail fastening industry is dramatically diversified but mainly empirical. In this work, a shear type and a bonded compressed type of rail fastening systems are investigated experimentally and numerically. Quasi-static and dynamic experiments are carried out and the results are analysed with different mechanical models. Besides, a series of fundamental rubber material tests is performed to accurately describe the rubber material used in the two fastening systems. The most appropriate hyperelastic and hysteresis models are chosen with the help of simulations by Abaqus. Also by using Abaqus, finite element analyses are conducted for the two fastening systems and the numerical results are compared with those of experiments. Material and geometrical nonlinear features observed in the measured displacement-force curves are analysed and explained. Finally, parameter sensitivity of the two fastening specimens are studied, followed by an optimization process to meet practical optimization objectives. The present work is believed to be helpful for understanding the mechanical behavior of rail fastening systems, while enlightening the engineering practice, and eventually improving product designing and optimizing measures