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148 Uppsatser om Crane loads - Sida 1 av 10

Gallring med vinkelkran : en jämförande studie av skördarkran med och utan horisontellt ledad vipparm

One of the most important components of a harvester is the crane. Most harvester cranes are only possible to pivot (or horizontally rotate) at the crane pillar. Cranab in Vindeln, Sweden, has developed a new type of harvester crane which has an extra pivot point on the outer boom. This makes it possible to reach around residual trees, easing thinning work in dense stands. The aim of the study was to analyze if the use of a pivoting outer boom (POB) crane gave an increase in thinning production and if there were any differences in time consumption between the work elements for the POB crane and a conventional crane. A Valmet 911.3 equipped with a POB crane was used in the study.

Jämförelse mellan BKR/BSK och Eurokoders behandling av utmattning i traversbalkar med tillhörande svetsfogar

This report has been performed for WSP Construction Design located at Arenavägen 7 in Stockholm. WSP Construction Design is one of the leading departments in Sweden in construction solutions regarding everything from building construction to industrial building. Great competencies regarding steel, wood and concrete constructions are available within the department which is well sought.Crane girders used in the industry are exposed to large loads that vary over time that includes instantaneous lifts and the crane girders movement which lead to the phenomenon fatigue in the crane girder and its ingoing welds. A control of fatigue needs to be performed after a certain lifespan measured in time which in turn is converted to a number of loadcycles. When the number of loadcycles amounts to a greater number the input welds resistance will have been reduced and the rate of utilization thereby increased.

Skadeanalys och omkonstruktion av HMS Belos A-ram

In order to rescue a distressed submarine crew, the Swedish Navy is able to use a deep submergence rescue vehicle, DSRV. This mini submarine ascends, docks to the downed submarine and picks up the whole crew. The submarine rescue ship HMS Belos has a special crane located in the aft of the ship to lift the surfaced DSRV aboard, which then docks on to the on board pressure chambers located below deck. During inspections the aforementioned crane has shown to have problems with cracks in the structure, most of them located in the bolted joint between the top part of the crane and the two leg parts. A simulation of the forces acting on the structure in heavy sea condition was conducted; these values were then used as input values in a Finite Element Method, FEM, analysis of the joint.

Dimensionering av Traverskranbana

Kranlaster som verkar på kranbanor varierar med tiden och kan inte behandlas som statiska laster, detta gör att en statisk beräkning inte är tillräckligt säker, därför bör kranbalkar utformas på så sett att den klarar av statiska såväl som dynamiska kranlaster.Arbetet valdes efter förstudier som gjordes på internet för att få grundläggande kunskap om ämnet. Informationen söktes på svenska, engelska och tyska för att kunna hitta relevanta och pålitliga källor som behandlar traverskranbanor enligt eurokod. Tack vare råd från Björn Åsted från Stålbyggnadsinstitutet (SBI), kunde en bok på tyska hittas. För att kunna jämföra resultaten används ett svenskt program CraneGirder EC3 under arbetet.Rapporten innehåller en beräkningsmodell för en valsad profil balk, beräkningar baserades på eurokod ekvationer och föreskrifter vilket var som dimensionerings underlag för arbetet. I denna rapport hänvisas hur en kranbana skall dimensioneras med hög utnyttjandegrad, ett antal kontroller gjordes för att säkerställa att balken och dess detaljer, såsom räl och svets är säkert utformade mot utmattning och deformation.

Drivarens produktivitet vid lossningsarbete :

During the last few years the harwarder has developed from a prototype into a market product. Holmen Skog owns two harwarders and uses two more owned by entrepreneurs. In previous studies it has been shown that the harwarder was a slow and expensive forwarder. In this study the unloading at road-site was studied. The goal was to describe the differences in time consumption between unloading two-sided or single-sided (only from side of the road) and also the difference between unloading with three and four assortments in the carrier.

ESC-analys och studering av knack på en "Diesel Dual Fuel"-motor

A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.

Fundament för kompaktkran : En universell lösning

This thesis describes the universalization, improvement and further development of acompact crane support frame for flatbed trucks. The work has been conducted at Eloch Fordonsteknik AB (henceforth EFAB) in Uppsala.The aim of the work has been to shorten the assembly time of the product. By doingso, the product can be kept on shelf, which in turn results in shorter lead time. Thishas been done by universalizing the support frame to be compatible with most of thechassis EFAB works with. Additionally, the entire construction has been made lighter,which will make it a more attractive choice for customers.A pre-study was conducted and information was gathered internally, as well asexternally, in order to ascertain that no limitation or possibility was overlookedduring the course of the project.One such limitation has been the geometry of the truck bed that the support frameshall be compatible with.

Prestation vid sönderdelning av GROT med olika typer av maskiner

There is a need for productivities data and data for different types of machines for comminution of logging residues. The lack of data and studies on GROT comminution makes it difficult to evaluate different chains for handling of residue fuels and make system analyses.Four types of machines with three different working principles were compared at six studies during winter conditions. Three to eleven trials during 9.5 to 30.7 minutes were made on each machine. Samples from the produced material at each study were sieved to determine the size distribution of the comminuted material. Samples were also taken from the studies for determination of moisture content.

Teoretisk och experimentell utvärdering av Lättelement AB:s takinfästning

Lattelement AB in Ornskoldsvik is one of the leading companies in Sweden in composite elements in walls, floors and roofs in particular. The company supplies elements to buildings located with a wide geographical variation, which means that the products are subjected to very different climate with regard to snow, wind and humidity. This places high demands and requires the elements to withstand large variable loads.The elements are made of lightweight beams with flanges of structural timber and beam webs made of OSB. These are bound together by nogging pieces with the same kind of structure. On top of the beams a nailed and glued plywood is added to absorb compressive forces and on the underside of the element a sheet of steel is added for tensile absorption.These elements are then attached to the building framework in different ways depending on the particular element height, loads and the structual supporting material of the frame work.

Diesel Dubbelbränsle Teknologi

The work covered in this report includes a literature study of the diesel dual fuel technology(hereinafter referred to as DDF). The literature study covers earlier work that has been doneregarding the use of compressed natural gas (CNG) and diesel in a DDF system. Moreover a onecylinder research diesel engine was fitted with a CNG fuel system for experimental testing. Theinstallation of the engine and the test cell is described. Results from the tests are presentedcovering emissions, heat release and pressure traces from the DDF-concept.During the literature study it was found that most research was related to heavy duty dieselengines.

Förbränning av träpellets och pelleterad halm i en 40 kW rosterreaktor

The project focus on combustion of softwood pellets and pellets in a 40 kW grate fire reactor at TEC-Lab. Dept Applied Physics and Electronics at Umeå University. Experiments were performed at four primary airs to fuel ratios (0.7 to 1.3), where aspects such as temperature profile, levels of gases (CO and NO), sintering-/-slagging and unburned fraction of the ashes were studied. Four different fuel loads were used for wood pellets (10, 20 and 30 kW) and one fuel load for straw (10 kW). Combustion of straw proved very difficult to ignite, and also led to other combustion-related technical problem such as slag formation due to the relatively low melting temperature-/-slag temperature of the straw.

Konstruktion av serviceutrustning till tunnelborrningsmaskin

The Master Thesis work this report is based upon has been conducted in cooperation with Svea Teknik AB. Svea Teknik is a consultant firm which is developing parts of a tunnel boring machine on behalf of Atlas Copco. The machine is being developed to mechanically excavate hard rock by fixating itself in the tunnel and then press a large rotating cutter-wheel equipped with disc-cutters against the tunnel wall. The disc-cutters are the tools that are in direct contact with the hard rock and are therefore exposed to extensive wear and needs to be replaced on a regular basis.The purpose of this Master Thesis has been to develop a service equipment that will enable time effective and safe changes of disc-cutters. The disc-cutters have a diameter of 17 inches and weigh about 130 kg.

Slöserijakt i betongdjungeln : En tidseffektivisering av monteringsprocessen inom stål- och betongprefab

The different aspects of each individual construction project such as the general conditions, design and economic restrictions as well as many more factors mean it is difficult to standardize building processes or plan in detail based on past experiences. As a result operational efficiency is often reduced, and unnecessary waste is generated. To make an organization more efficient and therefore reduce waste production everybody involved needs to appreciate and understand the improvements that can increase the organization?s efficiency. To investigate these improvements a time study was performed on two different construction sites, both of which involved buildings being constructed of prefabricated steel and concrete elements.

VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor

Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.

Utredning av energieffektiviseringspotential i ett flerbostadshus : Avseende på injustering av värmedistributionssystemet och installation av värmepump

The different aspects of each individual construction project such as the general conditions, design and economic restrictions as well as many more factors mean it is difficult to standardize building processes or plan in detail based on past experiences. As a result operational efficiency is often reduced, and unnecessary waste is generated. To make an organization more efficient and therefore reduce waste production everybody involved needs to appreciate and understand the improvements that can increase the organization?s efficiency. To investigate these improvements a time study was performed on two different construction sites, both of which involved buildings being constructed of prefabricated steel and concrete elements.

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