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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

Improving concept learning in green building by addressing students' learning styles and prior knowledge

Chunduri, Sreelatha 13 November 2008 (has links)
In green building there is a requirement for the collaboration of students from different disciplines in order to solve challenging problems. Successful collaboration depends on the establishment of a common understanding of the subject matter among those involved. To gain common understanding concept learning is critical. A concept learning process may be improved when factors affecting it are addressed. Prior knowledge and learning styles of the students may influence the way they learn concepts. This thesis is focused on studying the relationship between a concept learning process and prior knowledge and learning styles of students. An experiment was conducted by giving students concepts customized to their prior knowledge and learning styles. Tests were conducted at various stages and they were statistically analyzed with t-tests to determine if a difference existed between the two groups. The results indicated that the group which was given the customized material showed improvement in their concept learning over the group who were taught conventionally.
2

Optimizing Construction Estimation: A Case Study of the ETSU Football Stadium and the ETSU Fine Arts Center

Mitra, John Paul 01 May 2018 (has links)
Considering the complexity of the construction industry, it is vital to predict costs accurately throughout the entire planning, design, and construction process of a project. Various factors such as overhead, delays, cost variation, and program and scope play significant roles in determining the viability and profitability of a project. Thus, it is important to learn about what makes construction estimates so variable even among expert estimators within the same company. This study will look at the estimation methods used by BurWil Construction Company and Denark Construction, Inc. for the ETSU Football Stadium and the ETSU Fine Arts Center, respectively, as case studies for both post- and in-development construction projects. The estimates used in different phases of the projects will be compared against the most current cost of the project; the final cost for the Football Stadium and the most up-to-date costs for the Fine Arts Center. Also, the different phases of design and construction and their corresponding estimates will be inspected thoroughly. As an ending discussion of the study, optimization efforts will be considered to assess how current planning and estimation methods can be improved to reduce cost and time for all parties involved in the project.
3

Eurocodes : Beräkningsjämförelser mellan eurocodes och BKR

Källung, Patrik, Staaf, Pontus January 2008 (has links)
<p>In the year 2010 a transition will take place here in Sweden from the present rules how to dimension buildings in to the common rules with have been developed in Europe, the Eurocodes. Eurocode is the term for a collection standard that contains calculation rules in how to dimension constructions and buildings. They are developed by the European standardize committee.</p><p>The purpose with this examination work is to get an insight of what changes this will contribute to, and how it will affect the dimensioning. Are there going to be any differences in the dimension you finally chose?</p><p>To investigate these possible differences two constructions will be calculated first in the present Swedish rules, and then in the coming eurocodes.</p><p>One of these two constructions will be build completely in steel, while the other will be build completely in concrete. The steel building will have a beam and a column dimensioned, the concrete building will likewise have a beam and a column dimensioned. To reach as equivalent comparison as possible will the same load, geometry and circumstance prevail for both standards. Limitation has been done to only dimensioning the beam and the column who is most charged.      </p><p>After we performed the calculations we could make the conclusion that dimensioning with Eurocode a higher efficiency was received, a 10 % higher efficiency on the materials. The strength of the material is with calculations with Eurocode higher, and so are the loads. One of the reasons for this is that the securityclass is added to the loads in Eurocodes and are drawn off from the strength of the materials in BKR.         </p> / <p>År 2010 kommer en övergång att ske i Sverige från de nuvarande reglerna att dimensionera bärverk enligt BBK till de gemensamma reglerna som tagits fram i Europa de så kallade Eurocodes. Eurokoder är benämningen på en samling standarder som innehåller beräkningsregler för dimensionering av bärverk till byggnader och anläggningar. De tas fram av den europeiska standardiseringskommittén.</p><p>Syftet med examensarbetet är att skapa en överblick om vilka förändringar detta kommer att leda till och hur detta kommer att påverka dimensionering av bärverk samt om det kommer att bli några skillnader i vilken dimension man slutligen väljer.</p><p>För att komma fram till skillnaderna mellan de två olika standarderna så kommer två byggnader att dimensioneras, Byggnaderna kommer först att dimensioneras enligt de nuvarande reglerna enligt BBK, därefter så kommer samma beräkningar göras enligt de nya reglerna enligt eurocodes.</p><p>Byggnaderna som kommer att dimensioneras kommer att bestå av två material antingen bestående av stål eller betong. Byggnaden bestående av stål kommer att ha balk och pelare i stål och den andra byggnaden kommer att ha en pelare och balk bestående av betong. För att få en så likvärdig jämförelse som möjligt mellan de två olika standarderna så kommer samma typ av laster och förhållanden att verka på elementen. Begräsningar har gjorts att bara dimensionera den mest belastade balken respektive pelaren.</p><p>Efter att vi utfört beräkningarna drog vi slutsatsen att vid dimensionering enligt Eurocode erhålls en 10 % högre utnyttjandegrad av materialet än vi dimensionering enligt BKR.   Generellt vid beräkningarna så blir hållfasthetsvärdena större för Eurocode, kompenserande blir då också lasten större. En anledning till detta är att säkerhetsfaktorn läggs på lasten i Eurocode och reducerar kapaciteten i materialet för BKR.</p> / Beräkningsanalyser
4

Samverkanspelare i icke bärande fasadelement

Alamerison, Seif, Tarek, Karzan January 2009 (has links)
<p><strong>Abstract</strong><p>The tests work is about the subject "synergism of steel and concrete."</p><p>The construction sector is in a strong competition and the different companies in the Prefab</p><p>Market has ever tried to develop new design solutions that are efficient and environmentallyfriendly.</p><p>The purpose of this report is to highlight different aspects of interaction and size up a columndimension and to examine its efficiency and load capacity as Eurocode 3 and Eurocode 4. A sizing chart that describes the relationship between the torque and normal force shouldalso be made of the interaction .</p></p><p> </p>
5

Arrestor Hook för JAS 39 Gripen

Nåhdin, Rickard January 2010 (has links)
<p>SAAB AB är intresserad av att kunna utrusta JAS 39 Gripen med en "Arrestor Hook" då denna typ av nödbromssystem är vanligare i andra flygvapen än det system som svenska flygvapnet använder. Uppgiften var att göra ett konstruktionsförslag av denna "Arrestor Hook" bom och krok för kommande arbete.</p><p>För att göra detta förslag valdes att dela upp arbetet i fyra steg, faktainsamlig, konceptframtagande, konceptval och bearbetning.</p><p>Valet av vilka detaljer som skulle ingå i förslaget var böjd bom med med fast krok. På kroken monterades en släpsko för att underlätta fångandet av vajern och att tjäna som den detalj som skyddar kroken från slitage som uppstår mellan "Arrestor Hook" och banbeläggning. För att tillgodose alla krav på rörlighet som behövs på "Arrestor Hook" utrustas den med en leddetalj som ger tvåfrihetsgrader vilket även ger ett mindre moment på konstruktionen när vajern är fångad.</p><p>Resultatet av den teoretiska analysen av de fyra förslagen visar att alla de uppsatta kraven kan mötas, dock behövs mer utvärdering och tester för att säkerställa detta. Ytterligare litteratur kring tillvägagångssättet att konstruera "Arrestor Hook" bör också tillföras för fortsatt arbete.</p>
6

Smörjning Av Lager / Lubrication Of Bearing

Ahlman, Per-Arne January 2009 (has links)
<p>The work thesis was performed at Assalub a company which is situated in Åtvidaberg. The company works with developing, manufacturing and marketing equipment for handling of lubricants for light and heavier industry. The work thesis it is based on a inquiry Assalub got from MacGregor which is a company within cargo solution, from port to offshore system.</p><p>For unloading grain and other material from the ship cargo it is used combined inlet feeder and screw conveyor, there the inlet feeder is drilling down through the cargo and feed the screw conveyer with material to further destination. At the bottom of the screw conveyer and the inlet feeder there is a bearing that keep the parts together. However the lubrication of the bearing must be made manually. Until now the bearing was lubricated manually through a grease nipple from the bottom of the drill once a day.</p><p> </p><p>The purpose of the thesis was the construction of a lubricating system namely a pump with a grease container which should be placed inside the space of the screw conveyer, so the bearing will be continually lubricated and able to work several days without any stoppage.</p><p>After receiving drawings and operating data for the screw conveyer, the details for the construction was designed in CAD system Solid Edge. The solid mechanics calculations on the weakest point on the construction was made by hand and afterwards the drawings for respectively details was made.</p><p>The construction was completed, but because of the time limit for this work thesis, the manufacturing, mounting and testing were not included in these weeks. The grease containers capacity is approximately seventy-two hours, although desirable should be up to seven days. According to the solid mechanics calculations, the construction should have no problem to resist the stresses it would be exposed to.</p><p>Since this is a prototype there is probably some adjustments and improvements to do, but the estimating is that the system should work properly as it is now.</p>
7

Design of an End Effector for Drilling in Automated Processes

Åman, Robin January 2006 (has links)
<p>In an attempt to solve a problem concerning drilling, a project was started at the universities in Linköping and Lund. As a part of the project this thesis aims to help solve the drilling problem. The goal of this thesis is to design an end effector that will help avoid slipping when drilling. The methods used were taken from David G. Ullman’s book The Mechanical Design Process. Members involved in the project were interviewed to get an understanding of the task. With that done the concept generation phase began, resulting in several concepts. With the use of evaluation methods, such as feasibility judgment and Go/No-Go screening, a final concept emerged. All of the parts and details of the concept were designed with respect for the customers’ requirements and demands.</p>
8

Haspelsystemet Camcoil 1500

Blomberg, Andreas, Stöllman, Johan January 2008 (has links)
<p>Our employer Camatec Industriteknik AB gave us the assignments to increase theirs range of versions on Camcoil that is their own patent product. Camcoil is a capstan system that is used when steel band fabricated. Exist for example in production lines their steel band should be annealed. Our goal with this work is to come up with a completed production basis on a Camcoil for heavy industry. The basis should contain calculations, 3D-constructions, drawings and cost proposal on manufacturing and detail purchase.</p><p>Demands on this project:</p><p>1. 15 ton load</p><p>2. Strip width up to 1500 mm</p><p>3. Head diameter 610 mm</p><p>4. Production speed 35 m/min</p><p>5. Economy manufacturing</p><p>6. Be simple</p><p>Several concepts were decided out of the feasibility study. The concepts were compared against each other and finally only one was left. Result of the design concept became one shaft with three capstan heads and a support function.</p><p>One conceivable working process was planed with a Gantt-table. A decision was made that the work of the Camcoil should be separated in several details. Earlier work on Camcoil was study to increase our understanding for the work.</p><p>Some of the examined parts were shaft dimensions, bearings, head shape, tripod, support function and hydraulic cylinder for the capstan and support.</p><p>Some of the calculations have been made in Ansys. Directional deformation, Von Mises stress for the shaft, length of the hydraulic cylinder in the capstan heads and the stress for tripod and support function was calculated.</p><p>Analytic calculations were made on some parts. Frequency analysis for the system was made with Dunkerleys method. The reaction forces in the bearings were calculated with a combination of elementary case. Lifecycle of the bearings can with this be appreciated. Hydraulic cylinder strength in capstan heads and support function, locking assemblies, sheet metal thickness and control off beam dimensions in support was also decided with analytic calculations.</p><p>3D models were made on several details in the system. Models like lock rings, engines and bearings were taken from the supplier.</p><p>After the modeling assemble drawings and detail drawings were made for the whole capstan system. The drawings were sending to manufacturer for a cost proposal.</p>
9

Konstruktion av snabbkoppling för elektropolering.

Hurley, Daniel, Johansson, Carl January 2010 (has links)
No description available.
10

Physically Based Engineering Models for NCF Composites

Edgren, Fredrik January 2006 (has links)
Non-Crimp Fabrics - NCF – are increasingly being used as reinforcements in high performance composite materials. NCF offer the manufacturing advantages from textile preforms in combination with excellent mechanical performance. This study concerns the mechanical performance of NCF composites. Through a combination of experimental work and theoretical studies the mechanisms controlling the mechanical behaviour are explained. Fractography is used as a tool to identify governing mechanisms and link these to the material internal structure. Based on the experimental findings, engineering models are suggested predicting the mechanical behaviour of NCF composite laminates. A simplified constitutive model is presented that accounts for the fibre tow out-of-plane waviness. The model is based on Timoshenko beam theory applied on curved beams representing wavy tows in a NCF composite lamina. The model calculates stiffness knock-down factors to be applied on lamina homogenised properties. Experiments show compressive failure of NCF composites to be governed by formation and growth of kink bands. For this reason, a failure criterion predicting kinking failure under multiaxial loading is proposed and validated for a NCF composite system. The criterion is to be used on lamina level in a multiaxial NCF laminate. A test method is proposed for extraction of strength parameters valid for the lamina material in a multiaxial laminate. Compression-after-impact (CAI) behaviour of NCF composite laminates, as monolithic skins and sandwich panel face sheets, is investigated. Fractographic studies show CAI failure to be controlled by formation of kink bands. The experimental studies reveal that kink bands form at relatively low loads and grow gradually during compressive loading. It is suggested that the notch effect from the gradually developing kink bands cause final catastrophic failure in sandwich panel skins. Finite element analyses, simplistically representing the damage with an idealised notch, are shown to predict panel residual strength with reasonable accuracy. / QC 20110120

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