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Concept Study of Construction IngressOlsson, Sofia January 2008 (has links)
<p>The purpose of this thesis is to, on Volvo Truck’s account, look at a new concept for the construction ingress used on construction vehicles which have a higher ground clearance than ordinary trucks. The high ground clearance makes it hard for the driver to reach the first instep and therefore a construction ingress is assembled below the stationary insteps. It is designed in a way that avoids damage if colliding with objects.</p><p>The present construction ingress used is too expensive, too complex and a bit unsteady to climb on. There is also a new construction vehicle being developed and the old ingress might not fit the new truck.</p><p>The concept generation is carried out using systematic concept development. There are many demands and requests for the ingress and these are summarized in a design criterion list. All wished-for properties can not be fulfilled for the simplest ingress designs since they conflict with each other, for example flexibility and stability.</p><p>The concepts that are generated are evaluated and selected through different matrices until one concept is found to be the most promising. Different designs of this concept are discussed and one is chosen as the most suitable. The chosen concept design is already used by at least two competitors and that confirms its suitability.</p><p>The detailed design presented is only a suggestion for a new construction ingress. Before manufacturing the design needs to be analysed more accurately and the strength, material and cost need to be optimized. The analyses made in the project only show that the design is realistic and that it is worth further work. The final design is promising since it is stable to use, consists of only a few simple parts and will be cheap to manufacture.</p>
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Tonala skillnader mellan en traditionell och en modern gitarrkonstruktion : En jämförelse mellan två klassiska gitarrerGramstad, Lloyd January 2007 (has links)
During my studies to become a guitar builder at Carl Malmsten CTD, I have found an interest in the construction of the classical guitar. I am fascinated by the simplicity of its construction. A simplicity that becomes more complex when you start to study it in detail. In my final thesis I will not try to explain this complexity. The subject is to investigate two different principles regarding its construction. I would like to find out if the sayings concerning one of the principles will yield a guitar with greater ability to produce volume and projection. At a close distance the difference between the guitar’s volumes is not to speak of, but a significant difference can be seen regarding one of the guitars ability to project its sound. In their nearness tonal aspects becomes in some extent legible. Even if the two guitar’s character of sound is alike subtle tonal differences exists. The existing differences between the two principles of construction are regarding the two guitars that I have built. The subject for the examination is to conclude the guitar’s ability to project their sound nearby compared to at a distance.
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Konstruktion och utveckling av pneumatisk pressfixturNyberg, Michael January 2007 (has links)
Flextronics Design i Linköping, som ingår i den stora amerikanskägda Flextronics- koncernen, är en industrialiseringsenhet på mobiltelefonsidan. Det innebär att verksamheten kretsar kring att ta fram test- och monteringsprocesser, samt tillhörande utrustning, som sedan implementeras hos högvolymsfabrikerna belägna i olika låg-kostnads-länder. På mobiltelefonerna finns, beroende på modell, ett antal detaljer som pressas fast, antingen för hand, med en manuell press, eller med hjälp av en pneumatisk press. Den sistnämnda pressmetoden används när det rör sig om lite längre presstider på detaljen, från ett par sekunder och uppåt. Idag finns det två modeller som drivs med tryckluft och som pressar med olika kraftintervall beroende på vilket lufttryck som tillförs till systemet. Det har visat sig att det finns ett behov hos företaget att ta fram en ny konstruktion som pressar med ett lägre kraftintervall än de befintliga modellerna kan erbjuda. Det är önskvärt att reducera tillverkningskostnaden jämfört med tidigare modeller. Framförallt är en ny lösning på xy-bordet önskvärd då den står för en stor del av den totala kostnaden. För att tryckbilden, och därmed resultatet, ska bli så bra som möjligt är det också viktigt att konstruktionen går att kalibrera i x- och y-led, samt att även felaktigheter i planheten går att justera. Under konstruktionsarbetet har olika tekniska lösningar och koncept tagits fram som utvärderats. Den slutliga konstruktionen består av en tryckluftscylinder som är dimensionerad för att trycka med de krafter som är specificerade. Den rörliga delen av cylindern förs ner och pressar samman detaljen och telefonen som är placerade i en fixtur. Den är i sin tur fixerad i ett justerbart xy-bord som består av två aluminiumplattor med urfrästa spår. Inställningen av tryckbilden i x- och y-led sker med hjälp av styrpinnar. Eventuella skillnader i planheten verifieras redan vid monteringen av pressen, och justeras genom skimsning. Tillverkningskostnaden för den nya modellen har reducerats med 30 % jämfört med de tidigare pressarna. Konceptlösningen på det nya xy-bordet innebär en kostnadsminskning med 50 % mot det befintliga bordet.
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Component Meshing MethodologyÖhrblad, Henrik, Berglund, Henrik January 2008 (has links)
In order to achieve results that are reliable when using the finite element method one has to use an acceptable element mesh with respect to the shape and size of the elements. As a help to produce an acceptable mesh there are quality criteria that must be fulfilled in most pre-processors. One objective with this thesis is to perform a sensitivity study that can be used as a basis for a Mesh guideline for chassis parts which is requested from engineers at Volvo 3P. The software used in the sensitivity study is ANSA as pre-processor, Nastran as solver and Metapost as post-processor. In the first part of the sensitivity study three different models are used for studying quality criteria such as aspect ratio, skewness, mid point alignment, mid point deviation and element size. Solid elements of second order, which are used in the three models, can be generated in two ways, which constitutes another part of the sensitivity study. They may either be generated from the beginning or can be converted from first order elements. This means geometrically that if second order elements where generated from the beginning the element mesh would follow the shape of the component in a better way compared to the other method. Recently a pre- and post-processing program called SimLab was introduced on the market. Since SimLab supports geometry import from several CAD-systems without loss of feature information, the automatic element mesh generation is supposed to be better as the mesh generator has access to more information concerning the geometry. An evaluation of SimLab is the second major objective of the thesis. More specifically, the evaluation concerns the possibility of using the software at Volvo 3P. Results show a surprising insensitivity regarding the criteria and that the method of generating second order elements from the beginning is to be preferred. SimLab is a new program with big potential and the conclusion is that it is possible to use it at Volvo 3P.
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Motordrivet höj- och sänkbart TV-stativ : Motor-driven rise- and sinkable TV-standBergkvist, Sandra, Läbom, Malin January 2008 (has links)
Det här examensarbetet har genomförts i samarbete med företaget ROL Ergo som konstruerar och tillverkar motordrivna höj- och sänkbara skrivbord. Företaget vill utvidga sitt sortiment genom att marknadsföra motordrivna höj- och sänkbara TVstativ mot den offentliga sektorn. Stativet ska konstrueras efter samma tekniska lösningar och principer som företaget redan tillämpar. Uppdraget delades ut som ett examensarbete till Jönköpings Tekniska Högskola, JTH. Författarna har genom en tilldelad kravspecifikation och egna fältstudier på marknaden lagt grunden för utvecklingen av TV-stativet. Genom olika välkända arbetsmetoder har arbetet kartlagts, planerats i detalj och varit till hjälp vid beslut av större och mindre konceptval. Kraven samt önskemål från potentiella användare har bearbetas noggrant för att uppfyllas en i taget och har varit till stöd för beslut av teknisk och designmässig utformning. Konstruktionen baseras på förutbestämda delar som tilldelats av ROL Ergo och på undersökningar inom området ergonomi, laborationer, beräkningar samt diskussioner med handledaren på företaget. En grövre konstruktion utvecklades som grund för hela produkten och utifrån den kunde uppkomna problem diskuteras och lösas för att tillgodose merparten av kraven och önskningarna. Därefter utformades bit för bit i en detaljkonstruktionsfas för att till sist fungera tillsammans i en helhetslösning. Resultatet blev ett mobilt motordrivet TV-stativ som klarar TV-apparater upp till 42". Stativet är ergonomiskt anpassat för både en sittande och stående publik. TV-stativet är designat för att smälta bra in i en offentlig miljö och är därför diskret och stilrent utformat med få synliga detaljer. / This master's thesis has been performed in cooperation with the company ROL Ergo which design and manufacture motor-driven rise- and sinkable desks. The company wants to expand their assortment by marketing motor-driven rise- and sinkable TVstands towards the public service. The stand shall be designed with the same technical solutions and principles as the company already applies. The mission was given out as a master thesis to Jönköping University. The authors has through a given requirement specification and own field studies on the market made the foundation for the development of the TV-stand. Through different well known working methods the work has been charted, planed in detail and supporting in decisions of greater and smaller concept selections. The requirements and desiderates from potential costumers has accurately been worked thru to be fulfilled one at a time and they have also been supporting in decisions of technical and designable shaping. The constructions is build up with support from predetermined parts that was given from ROL Ergo and thru investigations in the ergonomic area, practical laboratory work, computing and discussions with the mentor on the company. A rough construction was developed as a base for the whole product and from that upcoming problems could be discussed and solved to supply the main part of the requirements and desires. After that piece by piece was designed in a detail construction phase to work together in the end as an overall solution. The result becomes a mobile motor-driven TV-stand that can take TVs up to 42". The stand is ergonomically suitable for both a sitting and standing audience. The TV-stand is designed to fit well in public services and is therefore styled discreet and sobered with few visible details.
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Design and Development of a Spray BoothAxelsson, Daniel January 2008 (has links)
As a part of a more extensive project of developing a new finishing line at the Bolivian door manufacturer Tecno Carpinteria San Pedro this thesis presents the development process for a special designed spray booth. The thesis covers every phase from a product idea to a final concept design. Working with finishing of furniture and other wooden products can effect the workers health in a negative way and damage the environment. The final result of the manufactured door is also depending on the how well the ventilation system in the working area is. Because of these reasons it is important to use safety equipment and a good ventilation system in the working area. As a part of this new finishing line San Pedro is in need of a special designed spray booth to control the spread of paint particles and other hazard substances that is a result of the finishing process. Together with the consultant firm CADEFOR a spray booth is designed and a proposal design is presented in this thesis. The result is a design built up with a dry filter solution together with an extractor that creates a cross draft airflow towards the rear part of the spray booth. The result of the project together with some recommendations of increasing the capacity in the finishing line are also presented.
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Controversial aspects of Commonwealth Construction and Engineering Procurement LawCraig, Ronald W. January 2000 (has links)
This research exposes to examination and understanding the law governing procurement of construction and engineering works and services. The thesis captures both development of common law and judicial determination of statutory law. It takes the form of published journal articles and conference papers which discuss legal issues relevant to construction procurement and conclude with recommendations for clients and construction project managers on how to better manage the procurement process. The work reveals, inter alia, the extent to which contract law regulates the tendering phase of construction procurement and places the client under an obligation to the tenderer characterised as 'fair dealing' or 'good faith'. Chapter 1 is of an introductory nature. Chapter 2 sets the crime of manslaughter arising out of construction site fatality as a procurement issue. The author notes the UK government's intention to introduce the new offences of reckless killing, killing by gross carelessness and corporate killing. Chapter 3 discusses cases where disaffected parties to the tendering process have made private law challenges of that process seeking compensation for the other party's alleged irregularities. The client is generally obliged in law to treat all tenderers equally and fairly and to refrain from evaluating tenders and awarding contracts other than in accordance with the rules set down in the tender conditions. Chapter 4 addresses the question: do traditional tendering processes encourage, or merely permit, contractor innovation? Several tender codes are reviewed to establish whether these codes provide for, or encourage, innovative proposals from competing bidders. Chapter 5 provides updating case material for the period 1999-2000 which helps to underpin the conclusions and recommendations set out in Chapter 12. Chapter 6 is a criticism of the NJCC's Code of Procedure for Single Stage Selective Tendering and the CIB's Code of Practice for the Selection of Main Contractors. Suggestions are made as to what a new tender code might include in the light of selected decisions of the common law courts. It is argued that a set of 'standard' tender rules should become the terms of a 'tender contract'. Those rules would properly reflect decisions of the courts and would be accepted by all parties to the process as a tender contract document. Chapter 7 discusses how the common law protects the integrity of construction procurement by imposed or assumed contractual obligations. Procurement of subcontract works is also considered. The author concludes that the tendering contract operates between main contractor and subcontractor as it does between owner/ developer and main contractor, and that the 'two contract' analysis provides the best basis for upholding integrity of the bidding process. Chapter 8 sets out advice for quantity surveyors and project managers derived from the decisions of the common law courts. The author argues that practice should be shaped to reflect the obligations assumed by parties in common law so as to avoid claims from aggrieved bidders. In Chapter 9 the focus shifts from private to public law. A Scottish court denied a remedy to the unsuccessful bidder on the grounds that the contract award process was unfair, unreasonable and in breach of natural justice. The author argues that a successful case might have been made out in private law and concludes with recommendations as to how the tender process might be better conducted. Chapter 10 deals with public procurement under the rules of the European Union (EU), noting a particularly important decision by the European Court of Justice that contracting authorities are obliged to treat all tenderers equally and fairly, a duty that parallels that found in common law and discussed in Chapters 2 through 8. Chapter 10 concludes with an article on Rv Portsmouth City Council (1996), reviewing both decisions at first instance and in the English Court of Appeal. Chapter 11 considers the risks of developers and contractors by examining the effectiveness of 'controls' imposed by common law when the usual statutory controls are temporarily withdrawn. It can be seen that the common law has not evolved to protect the interests of neighbours and local residents from the perils and hazards of property development which result in environmental degradation. This chapter concludes with recommendations as to how developer and constructors might minimise their impact on adjacent property owners. Chapter 12 presents a summary of the conclusions drawn from the completed research project and the author's recommendations for further research within the procurement topic.
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Comparative Analysis of Horizontal Directional Drilling Construction Methods in ChinaJanuary 2014 (has links)
abstract: As a developing nation, China is currently faced with the challenge of providing
safe, reliable and adequate energy resources to the county's growing urban areas as well as to its expanding rural populations. To meet this demand, the country has initiated massive construction projects to expand its national energy infrastructure, particularly in the form of natural gas pipeline. The most notable of these projects is the ongoing West-East Gas Pipeline Project. This project is currently in its third phase, which will supply clean and efficient natural gas to nearly sixty million users located in the densely populated Yangtze River Delta.
Trenchless Technologies, in particular the construction method of Horizontal
Directional Drilling (HDD), have played a critical role in executing this project by
providing economical, practical and environmentally responsible ways to install buried pipeline systems. HDD has proven to be the most popular method selected to overcome challenges along the path of the pipeline, which include mountainous terrain, extensive farmland and numerous bodies of water. The Yangtze River, among other large-scale water bodies, have proven to be the most difficult obstacle for the pipeline installation as it widens and changes course numerous times along its path to the East China Sea. The purpose of this study is to examine those practices being used in China in order to compare those to those long used practices in the North American in order to understand the advantages of Chinese advancements.
Developing countries would benefit from the Chinese advancements for large-scale HDD installation. In developed areas, such as North America, studying Chinese execution may allow for new ideas to help to improve long established methods. These factors combined further solidify China's role as the global leader in trenchless technology methods and provide the opportunity for Chinese HDD contractors to contribute to the world's knowledge for best practices of the Horizontal Directional Drilling method. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2014
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Konzept zum Parameteraustausch zwischen unterschiedlichen CAD/CAE-PlattformenBöhme, Carsten, Brökel, Klaus 28 September 2017 (has links) (PDF)
Einleitung und Motivation
Im ZIM-Projekt Vestainnen wird die Entwicklung einer stationären Wirbelschichtfeuerungsanlage (SWSF) kleiner Leistung fortgesetzt. Dabei liegen die Schwerpunkte auf der Modellierung und Simulation der Belastungen an Anlage und den Abläufen in der Feuerung.
Insgesamt sind am Projekt sieben Partner beteiligt, die parallel und weitgehend unabhängig arbeiten und die Entwicklung ihres Teilprojekts vorantreiben. Bedingt durch die Vielfalt der Aufgaben kommt bei jedem Partner eine eigene, für die Teilaufgabe geeignete Softwarelösung zum Einsatz. Um die Entwicklungsergebnisse jedoch gemeinsam nutzen zu können, müssen diese eigenständigen Teilmodelle jederzeit auf einen gemeinsamen Stand gebracht werden können, um dieselbe Baugröße und Konfiguration der SWSF abzubilden.
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LCA to support decision-making in layout designsGomes, Victor Emmanuel, Barba Junior, Durval João de, Gomes, Jefferson de Oliveira, Grote, Karl-Heinrich 28 September 2017 (has links) (PDF)
Introduction
The economic impact of environmental regulations in the manufacturing sector and the increasing costs of primary resources have pressured companies wishing to obtain competitive advantages to seek ways to rationalize these resources, either through changes in products specifications or in manufacturing process. These actions depend on solutions that should consider the limits set out in the interdependencies between economic, environmental and social areas, which comprise the so-called sustainability tripod. In this case, the guiding principle for decisions should follow the approach of sustainable development. For this purpose, a proper performance indicators evaluation of processes is a great step to improvement actions and decision making for modifications. Continuous improvement approaches and support of mathematical tools, such as the Discrete Event Simulation (DES) have been used for identifying waste on the shop floor and for cost analyses for manufacturing optimization (Standridge et al. 2006). One of the advantages resulting from the application of DES in corporations is its capability to include the impact of randomness in a system. All the dynamics and the non-deterministic nature of the parameters eliminate the use of static tools such as spreadsheets for solving many line design problems. Furthermore, all commercial simulation software provides detailed animation capabilities. The animation of the manufacturing process and flow can help engineers to visually detect problems or bottlenecks and also to test out alternate line designs. For this reason, the DES may be applied to generate requirements and sustainable systems specifications for manufacturing. However, the analyses results performed by using DES are not sufficient for the joint assessment of impacts on the three dimensions of sustainability (Johansson et al. 2010; Kuhl & Zhou 2009; Joschko et al. 2009).
A tool widely used in the academic environment and by corporations to calculate pollutant emissions rates in the product life cycle is Life Cycle Assessment (LCA). This can supplement cost assessments performed with DES in the production process phase. This work discusses the combined use of DES with LCA to analyze production resources utilization in manufacturing systems. Towards this end, it seeks through a case study to analyze this joint use in decision-making for purchasing forklifts, according to sustainable premises.
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