Sök:

Sökresultat:

713 Uppsatser om Dynamic simulations - Sida 1 av 48

Virtuell hållfasthetsprovning av en turistbuss

The competitive nature of the automotive industry has always implied a necessity to improve product development concerning time-to-market, cost and product quality. As capacity of computer-aided engineering (CAE) tools has evolved, so has the strive for simulation-driven design. Virtual durability testing using full vehicle models is one of many challenges posed in front of vehicle manufacturers when computer simulations are given a key role in product development.This thesis has been initiated as a preliminary step towards implementing dynamic virtual durability testing in the development of buses and coaches at Scania. The objective has been to assess the predictability of a full vehicle coach model and to what level of precision structural loads can be predicted. Previously performed proving ground testing of a Scania Touring coach has been the basis for the modelling and simulations in this thesis.A virtual model of the Scania Touring coach has been created in multi-body simulation software package MSC.Adams.

Missilstyrning med Model Predictive Control

This thesis has been conducted at Saab Bofors Dynamics AB. The purpose was to investigate if a non-linear missile model could be stabilized when the optimal control signal is computed considering constraints on the control input. This is particularly interesting because the missile is controlled with rudders that have physical bounds. This strategy is called Model Predictive Control. Simulations are conducted to compare this strategy with others; firstly simulations with step responses and secondly simulations when the missile is supposed to hit a moving target.

Projekt Air Control

Dynamic Air Diffuser.

Hållbara projekteringsverktyg : Från byggnadsinformationsmodell till simulering ? en utvärdering av Revit och Virtual Environment

This study examines the use of building modeling and energy simulations in the design process  of  a  building.  The  take-off  point  is  the  notion  of  energy  simulations  being needed early and throughout the building design process, and that the lack of energy simulations may be explained by the fact that they are time consuming and therefore often too expensive. A greater interoperability between software tools used by relevant disciplines,  such  as  the  architect  and  the  energy  specialist,  would  create  smoother workflows, which would reduce this cost and open up for more frequent and iterative energy  simulation  processes.  The  study  is  an  assessment  of  the  modeling  tool  Revit and  the  simulation  tool  Virtual  Environment  and  whether  they  can  create  smoother workflows, and make leeway for a more frequent use of energy simulations throughout the  design  process.  It  also  investigates  the  limitations  of  what  can  be  examined  by simulations in Virtual Environment. This will hopefully help clarify the future role of energy  simulations  in  design  processes.  The  method  is  a  trial  by  error  approach  of testing the two software tools by building and simulating a model. The results of these tests  show  that  the  workflow  is  not  optimal  (and  therefore  time  consuming)  for frequent  and  iterative simulations  throughout the  design  process,  but  it  also  reveals some  great  possibilities  of  what  can  be  performed  with  these  two  powerful  tools  at hand.  Further  development  with  regards  on  platform  independency  of  the  building information  model,  including  seamless  exporting  and  importing,  seems  necessary  to strengthen the future role of energy simulations..

En fordonsförares upplevelse av accelerationer som grund för en effektiv simuleringsmodell

Saab Aerosystems has a long tradition and a lot of competence in the field of flight simulation. Their ambition to broaden the market horizon has led to a discussion about also selling vehicle simulation solutions, both for military and civilian use.The aim of this thesis is to investigate the driver?s experiences of the accelerations he or she is exposed to whilst driving in rough terrain. The results may be used as a basis for future decisions and can act as a platform for the construction of an effective simulation model.To investigate the driver?s exposure of acceleration, some kind of dynamic simulation is needed.

Elektronstrukturbaserad magnetiseringsdynamik

In this project a method used for performing accurate simulations on magnetization dynamics based on constrained field density functional theory has been validated and used for performing computations on a few magnetic materials. The method has been shown to simulate systems consisting of iron well, but there are still problems with simulations of alloys containing both magnetic and non-magnetic materials..

Dynamisk investeringsstrategi på den svenska aktiemarknaden

The purpose of this paper is to investigate if a dynamic investment strategy on the Swedish asset market can accomplish better returns then a static investment strategy. The dynamic investment strategy is created by incorporating business cycle predictors and firm-level variables to predict future stock returns. The predictive regression is calculated wih 60 months of observation (1999 01-2005 12) and is then used to estimate future returns for 23 months in the period 2004 01 -2005 11. The structure of the regression, with linear functions of ? and ?, goes back to Shanken (1990) and Avramov and Chordia (2005) has had success with the variables chosen.

Överföring av elektrisk signal och effekt med magnetisk induktion.

This report tested the possibility of using induction as a mean for transferring data and power so that it can be implemented as a communication medium between a terminal and measuring head mounted in a measuring frame. This would eliminate the need for the cable bunches that are used today. For testing, signal generators were used to generateFSK-signals and were transferred with the help of inductors to the oscilloscope for signal detection, this to see how the coils used in the tests behaved. Simulations of a PLL were performed to see how good it could handle FSK-demodulation. With the help of a PLL IC and the simulations a working FSK-demodulator could be assembled.

Utveckling av dynamiska farthinder

The aim of this Master of Science Thesis is to develop guidelines and improvementsuggestions of RiNOVA Traffic AB?s dynamic speed bump. The project started with athorough pre study of the design and its function to find out how passing vehiclesaffects the dynamic speed bump. The majority part of the pre study was to createnecessary mathematical models to explain the arisen forces and strains.The results of the mathematical models gave necessary information about the designregarding weaknesses and flaws. The most critical ones where those which interferedwith the design?s performance and reliability, and therefore needed to be corrected.These problems where more thorough analysed and discussed with experts before thefinal guidelines and improvement suggestions where developed.The parts of the design that had to be redesigned were the extension springs and thebearing that enables the dynamic properties.

Kommersiella Fastighetshyror och Finansiell Stabilitet

In recent years, global organizations safeguarding financial stability has started to track commercial property markets. One of the reasons for this refers to the fact that commercial property constitutes a large share of bank lending. Simultaneously, bank exposures to commercial property are extensive and risky since collateral values are strongly correlated to borrowers cash flows. Since banks are viewed to play a key role for financial stability, studying the relationship is well motivated. To better understand how commercial property markets interact with financial stability, this paper develops an econometric model for studying the commercial rental market.

Jämförande simulering och modellering av framtida järnvägars elenergiförsörjning

In this thesis, the Train Power System Simulator (TPSS) has been compared and verified with the commercial simulator TracFeed® Simulation (TracFeed). The basis for the comparison was a given part of the Swedish railway system, with steel transportation trains. Primarily, emphasis was placed on running time and energy consumption in simulation results. Two transformer systems were analyzed, booster and auto transformers. The high voltage transmission line, parallel to the railroad track, was disconnected in some simulations.

Uljabuouda vindkraftpark turbinmodellering och stabilitetsanalys

This master thesis has been performed at Solvina in Gothenburg for Skellefteå Kraftand Vattenfall Eldistribution. The aim of it is to investigate the consequences of theinstallation of a wind power plant on the mountain Uljabuouda in the vicinity ofArjeplog. Especially the impacts on voltage and transient stability are examined.Furthermore, the amount of extra strain on the voltage regulation equipment and theneeds for increased regulation capabilities are looked into.The wind power plant is planned to be built by Skellefteå Kraft and connected to a130 kV grid owned by Vattenfall Eldistribution. The work comprehends the followingmain parts:- Theoretical studies aimed at wind turbines and power system stability issues.- Modelling of the type of wind turbines assumed to be built on Uljabuouda.- Simulations of different operation cases and analysis of the simulation results.The results from the simulations show that, as far as voltage stability and extraworkload on tap-changers are concerned, the wind power plant does not, in anysignificant manner, worsen the present conditions. The problem of overloading theline between Arvidsjaur and Vargfors is also minor.

Analys av spänningsstabilitetsberäkningar i det svenska elsystemet

Numerical simulations play a vital role in both static and dynamic stability assessment of electric power systems and the foreseeing of voltage collapse. Simulations performed by Svenska Kraftnät(SvK) are mainly done in the specialized voltage collapse predicting software tool, SPICA and the more all?purpose software tool, ARISTO.The grid operators at SvK use SPICA to predict the maximum transfer limit at specified sections (in this report the section in concerns is the southern part of Sweden i.e. interface1 4). SPICA is mainly used as an online application by using actual states from the grid, these states update every quarter of an hour.This thesis is a continuation of the master thesis SPICA ? ARISTO JÄMFÖRELSE by Jakob Katzman and Johan Fält.

Undersökning av modulationsscheman för existerande bredbandsteknologier

In this thesis some different modulation schemes for xDSL-techniques are compared. The investigated techniques are ADSL, G.lite, ADSL2, HDSL, SHDSL and VDSL. The modulation methods used are DMT, CAP and different versions of PAM. Several broadband techniques also use Trellis Coded Modulation (TCM) to increase the coding gain of the transmission. For each one of the different modulation methods the signal-to-noise ratio is calculated for generating a bit error rate probability of 10-7.

Dynamic obstructions of the equine upper respiratory tract

Dysfunction of the upper respiratory tract is a common cause of impaired performance and intolerance to exercise in racehorses and include several upper airway obstructions. The ones termed dynamic obstructions are primarily seen during physical exertion and affected horses often appear to be normal during endoscope examination at rest. The correlation between diagnoses made at rest respectively exercise is low, suggesting that an examination at rest alone is likely to be insufficient. The upper respiratory tract is exposed to great differences in pressure throughout the respiratory cycle; variations that are further altered during strenuous exercise and affect the rigidity of upper airway structures. In presence of great fluctuations in pressure, stability is achieved through coordinated and synchronous neuromuscular mechanisms. Due to nerve damage or anatomical abnormalities, these functions may be disrupted and further cause a dynamic collapse of the upper respiratory tract when pressure changes become too severe. The etiology behind the neuromuscular dysfunction is not yet fully understood.

1 Nästa sida ->