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4324 Uppsatser om Calculations model - Sida 5 av 289

Utmattning av vägbroar i armerad betong enligt eurokoder

Since 1 January 2010 it is a requirement to use the European standards, Eurocodes, in Sweden when constructing bridges. One chapter that has caused an extra amount of problems for the engineers is the one about fatigue analysis, which resulted in us doing this thesis.To do this we had to read all of the Eurocodes that direct, or indirect deals with fatigue and calculating of such. We have read the background documents for the Eurocodes and master?s thesis in the subject. We also studied the calculations of bridges constructed by different construction firms.We have chosen to limit the thesis to discuss only road bridges made of concrete due to the lack of method for verification of concrete in the national appendix.

Demonstrationsprojektets roll i framväxten av ny teknik: Fallstudier av två vindkraftprojekt

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Modellering av en panna med rörlig rost :  

The aim of this master thesis was to create a dynamic model for the processes in a solid fuel boiler of the moving grate type. Another aim with the model was to keep it as simple as possible but still able to catch the dynamics of the processes in the bedplate of the boiler. The creation of the model had its origin from drying and combustion equations used in earlier modeling work of boilers. The represented model has been used to simulate different kinds of disturbances in a boiler and different ways to control the boiler. These tests show that controlling a number of parameters in the bed of the boiler is an effective way to keep the grate stable during disturbances.

Adaptiv katalysatormodell för reglering

This master?s thesis describes the development of a model of the catalystsystem aiming at control by an MPC. A well functioning model, which is suitable in control purpose, is important while emission legislation become more and more hard to fulfill for the car manufacturers. Much research has been done in the field of physical modeling of the system, but in this work a linear adaptive time discrete ARX-model is developed and validated.The systems tendency to change its dynamic during usage implies that the model must be adaptive. The developed model proved to be well functioning and shows promising conditions for the MPC design.

Underhållskostnader för tröskor :

Costs of maintenance on combines are a subject of interest thus it constitute a large investment and cost for the individual farmer. Therefore it is important to have up to date knowledge and the right facts to be able to do reliable calculations on one of the largest investments for a farmer. The aim of this study was to compare costs of maintenance on combine/threshingmachine with the computer program for advising environmental issues in agriculture, STANK. Interviews took place and data were collected by handing out questionnaires to 20 farmers. A similar study conducted by Neuman (2003) investigated costs of maintenance and compared these with STANK. The results of this study have also been compared and examined related to data from SLA - Skogs och Lantarbetsgivarförbundet. The result shows that 18 out of 20 combines were given a higher cost of maintenance when using STANK compared to the numbers in this study.

Analys av turbulensmodeller för CFD

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulencemodel used in simulation of turbulent flow called PRNS (Partially Resolved NumericalSimulation). This model has promising properties and may be of use in savingcomputational resources. The purpose of this thesis was to analyze this model andcompare it with industrially applied models such as k-omega SST and LES (Large EddySimulations).PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation)where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1are selected. This constant is then used in the calculations and determines thebehavior of the simulation. When RCP is set to zero the equation are the same as fora DNS simulation and when RCP is set to one the equations for k-omega SST issolved.

Produktionskalkyler för biobränslen :

This study is one of five that has been done based on Lunds Energi?s planned investment in bioenergy. The plan is to build two large burners, at Örtofta, that?s going to be supplied with biofuels. In this study I take a closer look on the profitability when you choose to sell your cereal as bioenergy. I?ve been calculating with selling the straw from the grain crops and winter rape, selling the rye weat as whole crop and fertilize the hemp with sewage sludge.

FE-modellering av hjullast på sandwichpanel

This bachelor thesis in mechanical engineering was performed during the spring2015 in collaboration with Composite Consulting Group in Laholm. TheComposites Consulting Group works mainly with design and details of differentcomposite projects, their main area is FE-calculations, 3D-modelling andmechanical tests with composite materials.The aim of this bachelor thesis was to simplify the calculation process of solidmechanics for sandwich panels by simulation with computer software. The goalwas to decrease the time for the design and calculation process of the constructionand the cost of the practical tests. Our task was to build a static three dimensionalmodel with the computer software Abaqus, where the result should correspondwith the practical pressure tests in laboratory.The project started with collection of material data from Composites ConsultingGroup and by learning the software Abaqus, simultaneously a specification wasdeveloped in corporation with the company. Later on, a static wheel pressuremodel in the software Abaqus was produced which simulated the behavior of thesandwich panel during static wheel-pressure by a pallet truck.

Modell av en synkronmaskin för PSCAD/EMTDC med magnetisk mättning i d-led och elektriskt gränssnitt för fältmatare

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

Analys, modellering och återskapande av fordonsdynamiska rörelser i tåg

The purpose of this thesis was to analyse, model and finally generate dynamic vehicular motions in a train. The objective with the analysis was to find important motions for a realistic train experience. The motions from the analysis were then weighted against possibilities for generation in a motion platform.A dynamic motion model was created to model the selected motions. The model was implemented in a simulation environment, more specifically MATLAB/Simulink. The simulation environment was used to simulate the model and to generate outputs to control a motion platform.

?Vad är det jag gör egentligen?? - om att med videons hjälp bli medveten om helheten

This project consists of an adaptation, trial and evaluation of a model for practicing. Based on prior research I created a model aiming mainly to raise a musician?s self- awareness around the different parameters a performance consists of. An additional wish was for it to simultaneously assist the musician in monitoring his or her progress. With video recording and self-evaluation as the two main parts I tried the model by using it over a period of three months.

Multipel regressionsanalys av variabler som paverkar BNP

In this report a model was constructed in order to determine how a number of covariates influence the gross domestic product, GDP. The covariates were chosen depending on their expected influence on GDP, for example education and life expectancy. The data used in this report are collected from the World Bank. The model to describe GDP has been calculated using multiple line arregression. In order to reach a reliable final model the number of covariates has been gradually decreased to eliminate insignificant covariates.

Miljöcertifieringssystemet Miljöbyggnad : Inverkan på utformningen av ett kontor

The use and attention given to the certification system ?Miljöbyggnad? has increasedin recent years. The system is completely Swedish and was initiated in 2005 by theBygga-Bo-Dialogen. Miljöbyggnad aims to create a healthy indoor environment, reduceenergy consumption and discourage the use of hazardous chemical substances. Thegrades that can be obtained are Classified, Brons, Silver and finally Gold.The work has been to examine three different models and conclude how the designof the models affect the grades in the certification system Miljöbyggnad.

TV-stativ med nytt ställdon

The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.

Hudiksvalls samordningsmodell- en modell för att underlätta samverkan?

AbstractHudiksvalls coordinating model - a model to make cooperation easierCamilla Andersson and Åsa GradinThe purpose of this study was to examine the experience each one of the administrators have of their own new model in Hudiksvall to make cooperation easier for the three different administrations in Hudiksvalls municipality. The study will focus on the administrators experiences of Hudiksvalls coordinating design. Questions of the study were: How is the influence of the model on the rules? How is the influence of the model on expectations and parts? What kind of influence did the model have on the responsibility distribution? What kind of influence has the model on the responsibilities at the transfer of costs? To answer the questions of the study we applied a qualitative method, it was made through a standardization interview guide and open questions, with six of the dealing officers who works with the model. Some of the results wich can be discern are by an economic character, andfor the clients that they won`t be passed around the administrations in the community, they get the right help, quick and safe.Key words: cooperation, coordination..

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