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3875 Uppsatser om Wall shear stress - Sida 1 av 259
Spänningsanalys av axel-länkmekanism på borr-rigg
This master thesis is intended to give an increased understanding of the stress state in an axle, which is assembled in one of Atlas Copco?s mountain drilling rigs. The main problems investigated were how the axle is affected when the bearing is worn, when the pretension is varied, and how to dimension the axle. Answers to these questions were found by using hand calculations, practical testing and with Finite Element analyzes. The dimensioning of the axle is currently based on the bending stress, but the author?s opinion is that the axle should be dimensioned considering the equivalent stress.
Uppskattning av Ytkurvatur och CFD-simuleringar i Mänskliga Bukaortor
By applying a segmentation procedure to two different sets of computed tomography scans, two geometrical models of the abdominal aorta, containing one inlet and two outlets have been constructed. One of these depicts a healthy blood vessel while the other displays one afflicted with a Abdominal Aortic Aneurysm. After inputting these geometries into the computational dynamics software FLUENT, six simulations of laminar, stationary flow of a fluid that was assumed to be Newtonian were performed. The mass flow rate across the model outlet boundaries was varied for the different simulations to produce a basis for a parameter analysis study. The segmentation data was also used as input data to a surface description procedure which produced not only the surface itself, but also the first and second directional derivatives in every one of its defining spatial data points.
Vidhäftning mellan prefabelement och pågjutningsbetong : Undersökning hur skrovligheten påverkar vidhäftningskapaciteten vid skjuvning
Self-compacting concrete has soon been around for a decade. Recently the prefabrication industry has started to use this fairly new concrete type in larger scales, mainly because of its distinctive properties. There are still certain areas that need to be thoroughly examined, such as bond capacity. There have been very few studies regarding shear capacity due to the fact that the procedure is complicated.This report will highlight a method to examine the shear capacity of different surfaces that have been prewetted as well as non-prewetted surfaces. The surface areas follow BBK 04?s and Eurocode 2?s demand for surface roughness. A smooth surface will be completed in order to confirm if the different shapes influence the bond strength by shear stress or not. The purpose of this essay is to measure the bond strength within the shear capacity as well as examine the impact it has on surface roughness and treatment for shear bond.The method used to identify the shear capacity is called L-shaped Push-Off Test.
Korrelation mellan hållfasthet i kalkcementpelare och oförstärkt lera : En studie av sonderingar utförda på projekt BanaVäg i Väst
A today common soil reinforcement method is the installation of lime-cement columns. Lime-cement columns have been used since the 1970?s and have been a useful method for stabilizing soil at great depths. It is mostly used for stabilizing road and railway embankments because the method is economically viable and the columns are easy to install. The total costs for the installation of the lime-cement columns is dependent on the numbers of installed columns, what percentage of lime and cement that has been used and the pattern in which the columns has been installed.
Utformningen av ett förstärkt skruvförband på en differentialväxel i bandvagnen BvS10 : Analys av olika förband med hjälp av CATIA och MATLAB
This is a thesis presents a differential gear which is found in a tracked vehicle called BvS10. The tracked vehicle is manufactured by BAE Systems Hägglunds AB in Örnsköldsvik, Sweden. The differential gear has a bolted house. The differential meets the requirement specifications, but the problem is that the bolts are sheared off because of the extreme torque that the differential is exposed to resist.Previous report on the differential show pictures of bolts which have been sheared off at the threads. This report is also includes three lists that explain seven different proposals which some are approved and some are not, and the report also presents the force, tensile, and shear stress.In a bolted connection there is both axial tension stress and radial shear stress, which can lead to wear out and broken bolts.
Från ståtlig befästning till vittrande världsarv : En jämförelse av byggnadstekniska metoder för sammanbindning av skalmurar
This is a final year project considering constructional techniques for joining cavity walls. The project is related to an ongoing scientific programme about the restoration of The City wall of Visby located on Gotland. The programme was set by Riksantikvarieämbetet as a reaction to a collapse of the outer masonry wall shell which took place in February 2012.The City wall of Visby is a medieval fortification built out of limestone during the 13th century. The wall is constructed as a cavity wall with two separate masonry shells connected to each other through an intermediate core. During the 14th century the wall was heightened which lead to a higher stress, especially in the outer wall face.
Inverkan av tvång i gjutfogar och i betongkonstruktioner på
elastiskt underlag: Influence of Restraint in Casting Joints
and in Concrete Structures on Resilient Foundation
In this report, the risk of cracking in joints and/in adjacent concrete is estimated by checking shear forces in joints and the ratio between the actual maximum principal stress ant the actual strength of the concrete. The shear force has been estimated both by simple methods as well as by two-dimensional calculations. The risk of cracking in the concrete and/or in the joints is estimated with the computer program ConStre. The restraint from a resilient foundation or rock on a young concrete construction is estimated by a simple method that is exemplified. It is shown that the restraint can be neglected in some cases.
Experimentell undersökning av provkroppar för trälimfogar
This thesis engages the topic of test methods for wood adhesives. Two test methods were evaluated, EN 302-1, a European standard, and ASTM D905, an American standard. The total amount of specimens manufactured and tested was more than 500. The adhesive bonds were tested in shear with an increasing load on the specimen until failure.The adhesives used were epoxy-resin, phenol-resorcinol-formaldehyde and a 2-K polyurethane. The test programme included five different types of intentional errors per method, in order to investigate the sensitivity of the test methods.
Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus
This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse.
Framtagning av ny lager layout hos Allied Motion Stockholm AB - En studie om effektivisering av lager och intern materialflöde
This report is about the shear force design of reinforced concrete according to Europe?s common dimension rules, Eurocode. The purpose is to describe the calculation procedure and the background to the formulas and expressions that occurs. Furthermore results from different calculation methods (hand calculations and computer calculations) will be compared to see how they differ.The goal with this is to go through the parts of Eurocode dealing with shear force and that this will lead to a clear review of these. You should also be able to see how results and the calculation procedure differ between different calculation methods.
Tvärkraftsdimensionering av armerad betong : En utredning av beräkningsförfarandet
This report is about the shear force design of reinforced concrete according to Europe?s common dimension rules, Eurocode. The purpose is to describe the calculation procedure and the background to the formulas and expressions that occurs. Furthermore results from different calculation methods (hand calculations and computer calculations) will be compared to see how they differ.The goal with this is to go through the parts of Eurocode dealing with shear force and that this will lead to a clear review of these. You should also be able to see how results and the calculation procedure differ between different calculation methods.
Fuktskador i ytterväggar på grund av vattenintrång
Moisture damage in buildings is a serious issue that leads to problematic consequences and high economic costs. Despite the knowledge and awareness existing about moisture problems, extensive damager still occurs today. Studies of moisture in the exterior wall constructions shows that the issue if often caused by rain and water intrusion. These kinds of problem result in major costs usually because the companies have to replace the material and structural components and also in some cases tear down large parts of the buildings.The work includes moisture theory and descriptions of four different exterior wall constructions, wood stud wall with plastered facade, exterior wall with wood facade, exterior wall with concrete, and exterior wall with brick facade. Our thesis work describes how the constructions are affected and moisture damage due to water intrusion.
Tid- och kostnadsanalys av innerväggar
In our thesis we will compare interior walls, both bearing and non-bearing. All of thewalls analyzed are currently used in production by Skanska Construction, who is alsoour employer/supervisor for the project. The different wall types will be comparedfocusing mainly on time, cost and workability. All of these walls aside from the nonbearingwall are constructed using concrete, either prefabricated or cast on site..
Hisskärna av skalväggar i höga byggnader : Ett alternativ till den platsgjutna kärnan
A common way to stabilize high rise buildings is to use an elevator core built of concrete. Today, we use to build these elevator cores of in-situ concrete. Precast concrete twin wall (double wall) is a semi-finished product that has become more common in recent years. This diploma work studies how the twin wall works out as structural elements in an elevator core. The work also shows some possible ways of designing twin walls and highlights some important parts of the design that will be vital to the stability of the building. The result shows that it is important to think through where the element joints should be placed.
Prefabricerade väggelement av hampabetong
Lime Hempcrete consists of lime, water and hemp and creates an insulating, sound-absorbing, lightweight and environmentally friendly material that can be used in wall, roof and floor structures (Bevan & Woolley 2008). This construction method is not yet developed in Sweden as there has been a ban on the cultivation of the hemp plant. This ban on the cultivation of hemp was removed in 2003, when the material got a boost. You can use it in many different ways and not just in the construction industry (Ahlsten, 2010).In this study we have investigated the possibility to produce prefabricated wall elements of LHC. We have also studied its mechanical properties and dehydration time.