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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.
41

Modelem řízený návrh konferenčního systému / Model Based Design of the Conference System

Caha, Matěj January 2013 (has links)
This thesis deals with the topic of  model-based design and application of simulation in system design. In the introduction, the thesis discusses the history of software development process and outlines the current status. The aim is to demonstrate a model-driven design on a case study of conference system. There will be presented formalisms of DEVS and OOPN  together with experimental tools PNtalk and SmallDEVS that allow to work with these formalisms. The resulting model of conference system will be deployed as part of a web application using a framework Seaside in the Squeak environment.
42

Gerência de Interfaces para Sistemas de Informação: uma abordagem baseada em modelos / Interfaces Management to Information Systems: an models based approach

SILVA, Wilane Carlos da 16 April 2010 (has links)
Made available in DSpace on 2014-07-29T14:57:53Z (GMT). No. of bitstreams: 1 wilane_mestrado.pdf: 4461079 bytes, checksum: da62fa9aebf506f095f41942a579aecc (MD5) Previous issue date: 2010-04-16 / Building and maintaining a Graphical User Interface (GUI) for Enterprise Information Systems usually requires much Software Engineering staff time and effort. This paper describes a model-driven approach to create dynamically and manage these GUIs. In this approach, the Software Engineer designs conceptual models of the information system using object-oriented meta-models. A set of predefined mapping rules is applied to automatically transform and refine the conceptual models in order to generate, in runtime, the look and feel of the GUI, without source code creation. This improves the software usability, assuring consistency and homogeneity of the GUI, increases the productivity of the software engineering staff and simplifies maintenance. In our experiments we have observed an average productivity fifteen times higher than traditional methods of GUI development. / Construir e manter uma Interface Gráfica com Usuário (GUI) para Sistemas de Informação (SI) demanda muito tempo e esforço da equipe de Engenharia de Software. Esta dissertação descreve uma abordagem dirigida por modelos para criar dinamicamente e gerenciar essas interfaces. Nessa abordagem, o Engenheiro de Software projeta um modelo conceitual do sistema de informação usando um meta-modelo orientado a objetos. Um conjunto de regras de mapeamento predefinidas é aplicado para refinar e transformar o modelo conceitual do SI, gerando, em tempo de execução, a sua interface gráfica, com aparência e comportamentos específicos. Esse mecanismo melhora a usabilidade do software, assegurando consistência e homogeneidade das GUIs, aumenta a produtividade da equipe de Engenharia de Software e simplifica a manutenção do SI. Nos experimentos realizados foi observada uma média de produtividade quinze vezes maior do que os métodos tradicionais no desenvolvimento de GUIs.
43

Studies In The Dynamics Of Two And Three Wheeled Vehicles

Karanam, Venkata Mangaraju 12 1900 (has links) (PDF)
Two and three-wheeled vehicles are being used in increasing numbers in many emerging countries. The dynamics of such vehicles are very different from those of cars and other means of transportation. This thesis deals with a study of the dynamics of a motorcycle and an extensively used three-wheeled vehicle, called an “auto-rickshaw” in India. The commercially available multi-body dynamics (MBD) software, ADAMS, is used to model both the vehicles and simulations are performed to obtain insight into their dynamics. In the first part of the thesis, a study of the two wheeler dynamics is presented. A fairly detailed model of a light motorcycle with all the main sub-systems, such as the frame, front fork, shock absorbers , power train, brakes, front and rear wheel including tire slips and the rider is created in ADAMS-Motorcycle. The simulation results dealing with steering torques and angles for steady turns on a circular path are presented. From the simulation results and analytical models, it is shown that for path radius much greater than motorcycle wheel base, the steering torque and angle can be described by only two functions for each of the two variables. The first function is related to the lateral acceleration and can be determined numerically and the second function, in terms of the inverse of the path radius, is derived as an analytical approximation. Various tire and geometric parameters are varied in the ADAMS simulations and it is clearly shown that steady circular motion of a motorcycle can be reasonably approximated by only two curves–one for steering torque and one for steering angle. In the second part of the thesis, a stability analysis of the three-wheeled “autorickshaw” is presented. The steering instability is one of the major problems of the “auto-rickshaw” and this is studied using a MBD model created in ADAMS-CAR .In an Initial model the frame ,steering column and rear-forks (trailing arms) are assumed to be rigid. A linear eigenvalue analysis, at different speeds, reveals a predominantly steering oscillation, called a “wobble” mode, with a frequency in the range of 5 to 6Hz. The analysis results show that the damping of this mode is small but positive up to the maximum speed(14m/s) of the three-wheeled vehicle. Experiments performed on the three-wheeled vehicle show that the mode is unstable at speeds below 8.33m/s and thus the experimental results do not agree with the model. Next, this wobble instability is studied with an analytical model, similar to the model proposed for wheel shimmy problem in aircrafts. The results of this model show that the wobble is stable at low speeds regardless of the magnitude of torsional stiffness of steering column. This is also not matching with the experimental result. A more refined MBD model with flexibility incorporated in the frame, steering column and the trailing arm is constructed. Simulation results with the refined model show three modes of steering oscillations. Two of these are found to be well damped and the third is found to be lightly damped with negative damping at low speeds, and the results of the model with the flexibility is shown to be matching reasonably well with the experimental results. Detailed simulations with flexibility of each body incorporated, one at a time, show that the flexibility in the steering column is the main contributor of the steering instability and the instability is similar to the wheel shimmy problem in aircrafts. Finally, studies of modal interaction on steering instabilities and parametric studies with payload and trail are presented.
44

9. SAXON SIMULATION MEETING : Präsentationen und Vorträge des 9. Anwendertreffens am 28. März 2017 an der Technischen Universität Chemnitz

09 June 2017 (has links)
Von der Professur Montage- und Handhabungstechnik der Fakultät für Maschinenbau der Technischen Universität Chemnitz wird seit 2009 das jährliche Simulationsanwendertreffen SAXSIM organisiert. Ausgewählte Beiträge werden in Form eines Tagungsbandes veröffentlicht. Das 9. Anwendertreffen SAXSIM fand am 28.03.2017 an der TU Chemnitz statt. / The Chair of Assembly and Handling Technology, which belongs to the Faculty of Mechanical Engineering, has organized the annual simulation user meeting SAXSIM since 2009.  Select contributions will be published in conference proceedings.  The 9th SAXSIM user meeting took place at Technische Universität Chemnitz on March 28, 2017.
45

New modelling and simulation methods to support clean marine propulsion

Grant, Michael 24 August 2021 (has links)
The marine industry has increased its adoption of pure-electric, diesel-electric, and other non-traditional propulsion architectures to reduce ship emissions and fuel consumption. While these technologies can improve performance, the design of a propulsion system becomes challenging, given that no single technology is superior across all vessel types. Furthermore, even identical ships with different operating patterns may be better suited to different propulsion technologies. Addressing this problem, previous research has shown that if key elements of a vessel's operational pro file are known, simulation and optimization techniques can be employed to evaluate multiple propulsion architectures and result in a better propulsion system design and energy management strategy for a given vessel. While these studies have demonstrated the performance improvements that can be achieved from optimizing clean marine propulsion systems, they rely on vessel operational profiles obtained through physical measurement from existing ships. From a practical point of view, the optimization of a vessel's propulsion system needs to occur prior to a vessel's construction and thus precludes physical measurement. To this end, this thesis introduces a marine simulation platform for producing vessel operational profiles which enable propulsion system optimization during the ship design process. Core subsystem modules are constructed for simulating ship motions in 3 degrees of freedom and result in operational profile time-series, including propulsion power. Data is acquired from a benchmark vessel to validate the simulation. Results show the proposed approach strikes a balance between speed, accuracy, and complexity compared with other available tools. / Graduate
46

9. SAXON SIMULATION MEETING : Präsentationen und Vorträge des 9. Anwendertreffens am 28. März 2017 an der Technischen Universität Chemnitz

Berger, Maik 09 June 2017 (has links)
Von der Professur Montage- und Handhabungstechnik der Fakultät für Maschinenbau der Technischen Universität Chemnitz wird seit 2009 das jährliche Simulationsanwendertreffen SAXSIM organisiert. Ausgewählte Beiträge werden in Form eines Tagungsbandes veröffentlicht. Das 9. Anwendertreffen SAXSIM fand am 28.03.2017 an der TU Chemnitz statt.:- Multiphysikalische Systemsimulation mit SimulationX / Adam Burkhard - Modellierung & Simulation des Plasmaschweißens zur Entwicklung innovativer Schweißbrenner / Dr.-Ing. habil. Khaled Alaluss - Dynamischer Partikelbruch: Modelldefinition, Kalibrierung und Anwendung / Dr.-Ing. Luca Benvenuti - Konstruktionsbegleitende Toleranzsimulation mit CETOL 6 σ unter Verwendung der GPS-Strategie DIN EN ISO 14638 und DIN EN ISO 8015 / Dipl.-Ing. (FH) Christoph Bruns - PTC CREO SIMULATE ENGINE UPDATES / Dr. Arun Chavan - CREO SIMULATE : ROADMAP / Jose Coronado - Simulationsbasierte Entwicklung und Optimierung von Werkzeugmaschinen / Dipl.-Ing. Uwe Eiselt - Validierung des Kontaktmoduls der Freeware Z88Aurora anhand analytischer Beispiele und kommerzieller FE-Systeme / Christian Glenk M.Sc. - Mehrkörpersimulation eines ebenen Koppelgetriebes mittels Matlab/ADAMS-Co-Simulation / Dipl.-Ing. Christian Gollee - Numerische Auslegung des Mehrlagenschweißens als additives Fertigungsverfahren / Dr.-Ing. Marcel Graf - Berechnung und Simulation von Kurvenschrittgetrieben / Dr.-Ing. Andreas Heine - Parameterstudien und Co-Simulation ebener Koppelgetriebe / Stefan Heinrich M.Sc. - Erfassung, Simulation und Weiterverarbeitung menschlicher Bewegungen mit DYNAMICUS / Dipl. -Math. Heike Hermsdorf - Linear Dynamic System Analyses with Creo Simulate / Dr.-Ing. Roland Jakel - Strömungssimulation zur Optimierung von Flussfeldern in PEM-Brennstoffzellen / Philipp Jendras M.Sc. - Konvergenz eines plastischen Multiphysics-Kontaktes in der Pressschweißsimulation - Herausforderungen und Lösungsansätze / Jonny Kaars M.Eng. - Kurvenabgleich zur Bestimmung eines Systemverhalten und von Materialparametern / Dipl.-Ing. Rene Kallmeyer - Die kinematische und statische Analyse eines Biglide-Getriebes mit Hilfe der Programme Mathcad und GeoGebra / Dr.-Ing. Hanfried Kerle - Möglichkeiten der TexMind Software für Generierung von textilen Strukturen für FEM Simulationen und CAD Anwendungen / Prof. Dr. Yordan Kyosev - Prozesssimulation einer Rotorflechtmaschine nach „Horn“ zur Ermittlung der Flechtfadenspannung / Robert Laue M.Sc. ; Dr.-Ing. Daniel Denninger - Bruch einer Königswelle einer 6300 t Presse / Prof. Dr-Ing. Uwe Mahn - Strukturzuverlässigkeit durch Frequenzganganalyse mit Finite-Elemente-Methode im Rahmen des Projektes DRESDYN / Dipl.-Ing. M.Eng. Anton Melnikov - Systemübergreifender Simulationsansatz zur Auslegung, Fertigung und Qualitätssicherung am Beispiel einer Bogenverzahnung / Dipl.-Ing. Jürgen Merz - Integrative Prozess- und Bauteilsimulation für kurzfaserverstärkte Spritzgießbauteile / Dr.-Ing. Sascha Müller - Computergestützte Simulationsschnittstelle - Optimierte Systementwicklung / Dipl.-Ing. Sam Nezhat - Formatabhängige hochdynamische Bewegungen mit Servoantrieben / Dipl.-Ing. Dipl.-Inform. Rainer Nolte - Integration der Diskrete Elemente Methode in die domänen-übergreifende Systemsimulation / Dipl.-Ing. Christian Richter - Mehrkörpermodellierung und Validierung einer 3 MW Windturbine / Andreas Schulze M. Sc. - Vergleich von Stützstrukturen für die additive Fertigung: Creo Parametric/Simulate 4.0 & ProTOpCI / Dipl.-Ing. (FH) Urs Simmler - MFBD-Simulation des Nadeleindringens in ein Gewebephantom am Beispiel der Stanzbiopsie / Thorsten Speicher M.Eng. ; Katharina Hauschild M.Sc. - ANSYS AIM: Der Konzeptsimulator für alle / Dipl.-Ing. Marc Vidal - Neue Schweißfunktionalität in Creo 4 mit den daraus entstehenden Vorteilen zur Simulation / Axel Waidmann - Entwicklung eines zwangläufigen Schneid- und Fixiersystems für den Einsatz in einem Tapelegekopf / Dipl.-Ing. Rainer Wallasch / The Chair of Assembly and Handling Technology, which belongs to the Faculty of Mechanical Engineering, has organized the annual simulation user meeting SAXSIM since 2009.  Select contributions will be published in conference proceedings.  The 9th SAXSIM user meeting took place at Technische Universität Chemnitz on March 28, 2017.:- Multiphysikalische Systemsimulation mit SimulationX / Adam Burkhard - Modellierung & Simulation des Plasmaschweißens zur Entwicklung innovativer Schweißbrenner / Dr.-Ing. habil. Khaled Alaluss - Dynamischer Partikelbruch: Modelldefinition, Kalibrierung und Anwendung / Dr.-Ing. Luca Benvenuti - Konstruktionsbegleitende Toleranzsimulation mit CETOL 6 σ unter Verwendung der GPS-Strategie DIN EN ISO 14638 und DIN EN ISO 8015 / Dipl.-Ing. (FH) Christoph Bruns - PTC CREO SIMULATE ENGINE UPDATES / Dr. Arun Chavan - CREO SIMULATE : ROADMAP / Jose Coronado - Simulationsbasierte Entwicklung und Optimierung von Werkzeugmaschinen / Dipl.-Ing. Uwe Eiselt - Validierung des Kontaktmoduls der Freeware Z88Aurora anhand analytischer Beispiele und kommerzieller FE-Systeme / Christian Glenk M.Sc. - Mehrkörpersimulation eines ebenen Koppelgetriebes mittels Matlab/ADAMS-Co-Simulation / Dipl.-Ing. Christian Gollee - Numerische Auslegung des Mehrlagenschweißens als additives Fertigungsverfahren / Dr.-Ing. Marcel Graf - Berechnung und Simulation von Kurvenschrittgetrieben / Dr.-Ing. Andreas Heine - Parameterstudien und Co-Simulation ebener Koppelgetriebe / Stefan Heinrich M.Sc. - Erfassung, Simulation und Weiterverarbeitung menschlicher Bewegungen mit DYNAMICUS / Dipl. -Math. Heike Hermsdorf - Linear Dynamic System Analyses with Creo Simulate / Dr.-Ing. Roland Jakel - Strömungssimulation zur Optimierung von Flussfeldern in PEM-Brennstoffzellen / Philipp Jendras M.Sc. - Konvergenz eines plastischen Multiphysics-Kontaktes in der Pressschweißsimulation - Herausforderungen und Lösungsansätze / Jonny Kaars M.Eng. - Kurvenabgleich zur Bestimmung eines Systemverhalten und von Materialparametern / Dipl.-Ing. Rene Kallmeyer - Die kinematische und statische Analyse eines Biglide-Getriebes mit Hilfe der Programme Mathcad und GeoGebra / Dr.-Ing. Hanfried Kerle - Möglichkeiten der TexMind Software für Generierung von textilen Strukturen für FEM Simulationen und CAD Anwendungen / Prof. Dr. Yordan Kyosev - Prozesssimulation einer Rotorflechtmaschine nach „Horn“ zur Ermittlung der Flechtfadenspannung / Robert Laue M.Sc. ; Dr.-Ing. Daniel Denninger - Bruch einer Königswelle einer 6300 t Presse / Prof. Dr-Ing. Uwe Mahn - Strukturzuverlässigkeit durch Frequenzganganalyse mit Finite-Elemente-Methode im Rahmen des Projektes DRESDYN / Dipl.-Ing. M.Eng. Anton Melnikov - Systemübergreifender Simulationsansatz zur Auslegung, Fertigung und Qualitätssicherung am Beispiel einer Bogenverzahnung / Dipl.-Ing. Jürgen Merz - Integrative Prozess- und Bauteilsimulation für kurzfaserverstärkte Spritzgießbauteile / Dr.-Ing. Sascha Müller - Computergestützte Simulationsschnittstelle - Optimierte Systementwicklung / Dipl.-Ing. Sam Nezhat - Formatabhängige hochdynamische Bewegungen mit Servoantrieben / Dipl.-Ing. Dipl.-Inform. Rainer Nolte - Integration der Diskrete Elemente Methode in die domänen-übergreifende Systemsimulation / Dipl.-Ing. Christian Richter - Mehrkörpermodellierung und Validierung einer 3 MW Windturbine / Andreas Schulze M. Sc. - Vergleich von Stützstrukturen für die additive Fertigung: Creo Parametric/Simulate 4.0 & ProTOpCI / Dipl.-Ing. (FH) Urs Simmler - MFBD-Simulation des Nadeleindringens in ein Gewebephantom am Beispiel der Stanzbiopsie / Thorsten Speicher M.Eng. ; Katharina Hauschild M.Sc. - ANSYS AIM: Der Konzeptsimulator für alle / Dipl.-Ing. Marc Vidal - Neue Schweißfunktionalität in Creo 4 mit den daraus entstehenden Vorteilen zur Simulation / Axel Waidmann - Entwicklung eines zwangläufigen Schneid- und Fixiersystems für den Einsatz in einem Tapelegekopf / Dipl.-Ing. Rainer Wallasch
47

10. SAXON SIMULATION MEETING : Präsentationen und Vorträge des 10. Anwendertreffens am 22. März 2018 an der Technischen Universität Chemnitz

Berger, Maik 22 June 2018 (has links)
Von der Professur Montage- und Handhabungstechnik der Fakultät für Maschinenbau der Technischen Universität Chemnitz wird seit 2009 das jährliche Simulationsanwendertreffen SAXSIM organisiert. Ausgewählte Beiträge werden in Form eines Tagungsbandes veröffentlicht. Das 10. Anwendertreffen SAXSIM fand am 22.03.2018 an der TU Chemnitz statt. / The Chair of Assembly and Handling Technology, which belongs to the Faculty of Mechanical Engineering, has organized the annual simulation user meeting SAXSIM since 2009. Select contributions will be published in conference proceedings. The 10th SAXSIM user meeting took place at Technische Universität Chemnitz on March 22, 2018.
48

11. SAXON SIMULATION MEETING : Präsentationen und Vorträge des 11. Anwendertreffens am 26. März 2019 an der Technischen Universität Chemnitz

Berger, Maik 05 July 2019 (has links)
Von der Professur Montage- und Handhabungstechnik der Fakultät für Maschinenbau der Technischen Universität Chemnitz wird seit 2009 das jährliche Simulationsanwendertreffen SAXSIM organisiert. Ausgewählte Beiträge werden in Form eines Tagungsbandes veröffentlicht. Das 11. Anwendertreffen SAXSIM fand am 26.03.2019 an der TU Chemnitz statt. / The Chair of Assembly and Handling Technology, which belongs to the Faculty of Mechanical Engineering, has organized the annual simulation user meeting SAXSIM since 2009. Select contributions will be published in conference proceedings. The 11th SAXSIM user meeting took place at Technische Universität Chemnitz on March 26, 2019.
49

12. SAXON SIMULATION MEETING : Präsentationen und Vorträge des 12. Anwendertreffens am 7. März 2023 an der Technischen Universität Chemnitz

Berger, Maik 24 May 2023 (has links)
Von der Professur Montage- und Handhabungstechnik der Fakultät für Maschinenbau der Technischen Universität Chemnitz wird seit 2009 das jährliche Simulationsanwendertreffen SAXSIM organisiert. Ausgewählte Beiträge werden in Form eines Tagungsbandes veröffentlicht. Das 12. Anwendertreffen SAXSIM fand am 07.03.2023 an der TU Chemnitz statt. / The Chair of Assembly and Handling Technology, which belongs to the Faculty of Mechanical Engineering, has organized the annual simulation user meeting SAXSIM since 2009. Select contributions will be published in conference proceedings. The 12th SAXSIM user meeting took place at Technische Universität Chemnitz on March 07, 2023.
50

Numerical Methods for Modeling Dynamic Features Related to Solid Body Motion, Cavitation, and Fluid Inertia in Hydraulic Machines

Zubin U Mistry (17125369) 12 March 2024 (has links)
<p dir="ltr">Positive displacement machines are used in various industries spanning the power spectrum, from industrial robotics to heavy construction equipment to aviation. These machines should be highly efficient, compact, and reliable. It is very advantageous for designers to use virtual simulations to design and improve the performance of these units as they significantly reduce cost and downtime. The recent trends of electrification and the goal to increase power density force these units to work at higher pressures and higher rotational speeds while maintaining their efficiencies and reliability. This push means that the simulation models need to advance to account for various aspects during the operation of these machines. </p><p dir="ltr">These machines typically have several bodies in relative motion with each other. Quantifying these motions and solving for their effect on the fluid enclosed are vital as they influence the machine's performance. The push towards higher rotational speeds introduces unwanted cavitation and aeration in these units. To model these effects, keeping the design evaluation time low is key for a designer. The lumped parameter approach offers the benefit of computational speed, but a major drawback that comes along with it is that it typically assumes fluid inertia to be negligible. These effects cannot be ignored, as quantifying and making design considerations to negate these effects can be beneficial. Therefore, this thesis addresses these key challenges of cavitation dynamics, body dynamics, and accounting for fluid inertia effects using a lumped parameter formulation.</p><p dir="ltr">To account for dynamics features related to cavitation, this thesis proposes a novel approach combining the two types of cavitation, i.e., gaseous and vaporous, by considering that both vapor and undissolved gas co-occupy a spherical bubble. The size of the spherical bubble is solved using the Rayleigh-Plesset equation, and the transfer of gas through the bubble interface is solved using Henry's Law and diffusion of the dissolved gas in the liquid. These equations are coupled with a novel pressure derivative equation. To account for body dynamics, this thesis introduces a novel approach for solving the positions of the bodies of a hydraulic machine while introducing new methods to solve contact dynamics and the application of Elasto Hydrodynamic Lubrication (EHL) friction at those contact locations. This thesis also proposes strategies to account for fluid inertia effects in a lumped parameter-based approach, taking as a reference an External Gear Machine. This thesis proposes a method to study the effects of fluid inertia on the pressurization and depressurization of the tooth space volumes of these units. The approach is based on considering the fluid inertia in the pressurization grooves and inside the control volumes with a peculiar sub-division. Further, frequency-dependent friction is also modeled to provide realistic damping of the fluid inside these channels.</p><p dir="ltr">To show the validity of the proposed dynamic cavitation model, the instantaneous pressure of a closed fluid volume undergoing expansion/compression is compared with multiple experimental sources, showing an improvement in accuracy compared to existing models. This modeling is then further applied to a gerotor machine and validated with experiments. Integrating this modeling technique with current displacement chamber simulation can further improve the understanding of cavitation in hydraulic systems. Formulations for body dynamics are tested on a prototype Gerotor and Vane unit. For both gerotor and vane units, comparisons of simulation results to experimental results for various dynamic quantities, such as pressure ripple, volumetric, and hydromechanical efficiency for multiple operating conditions, have been done. Extensive validation is performed for the case of gerotors where shaft torque ripple and the motion of the outer gear is experimentally validated. The thesis also comments on the distribution of the different torque loss contributions. The model for fluid inertia effects has been validated by comparing the lumped parameter model with a full three-dimensional Navier Stokes solver. The quantities compared, such as tooth space volume pressures and outlet volumetric flow rate, show a good match between the two approaches for varying operating speeds. A comparison with the experiments supports the modeling approach as well. The thesis also discusses which operating conditions and geometries play a significant role that governs the necessity to model such fluid inertia effects in the first place.</p>

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