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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.
121

Lifting aid for roof top tents : Produktutveckling med ergonomi / Lyfthjälpmedel för montering av taktält

Svensson, Daniel, Rönneke, William January 2024 (has links)
This thesis focuses on the development of a lifting device for roof mounted tents at the requestof Thule with the focus on improving the ergonomics during installation and removal of roofmounted tents on vehicles, while also enabling the process for one to two users. The work isstructured according to the Double Diamond model and uses established product developmentmethods to ensure a systematic process.The preliminary study consists of an analysis of ergonomic risk factors during heavy liftingusing the Swedish Work Environment Agency's (Arbetsmiljöverket) assessment template andRapid Upper Limb Assessment (RULA). These tools were used to evaluate current users ownsolutions for lifting roof mounted tents.After screening and selecting developed concepts, an existing plasterboard lift was modified tocreate a prototype. Modeling work was carried out in SolidWorks, where various componentsand modifications were visualized and tested before being integrated into the plasterboard lift.The final prototype integrates functions that enable tilt and lifting of the roof tent, whichreduces the need for manual lifting and thus the risk of physical damage because of overloadsas well as minimizing needed storage space.The prototype was tested and evaluated where the results showed an improvement inergonomics and ease of use during lifting, facilitating movement of roof mounted tents betweenvehicles and storage while being able to be stored together with the tent with minimal impacton space requirements.Lastly, the work suggests further strength tests and investigation of better suited lift functionsfor future development to improve safety and lifting device efficiency. / Detta examensarbete fokuserar på utvecklingen av en lyftanordning för taktält på begäran avThule med huvudfokus att förbättra ergonomin vid på- och avmontering av taktält på fordonoch förenkla momentet för en till två personer. En framtagen lösning ska även bidra till minskadbränsle- och energiförbrukning för fordonet då det ska vara enklare och mer inspirerande attmontera av taktältet från fordonet när det inte är planerat att användas.Arbetet är strukturerat enligt Double Diamond-modellen och använder etableradeproduktutvecklingsmetoder för att säkerställa en systematisk process.Förstudien består av analys av ergonomiska riskmoment vid tunga lyft med hjälp avarbetsmiljöverkets bedömningsmall och Rapid Upper Limb Assessment (RULA). Dessa verktyganvändes för att utvärdera nuvarande användares egna lösningar för lyft av taktält. Eftersållning och val av framtagna koncept modifierades en befintlig gipsskivlyft för att skapa enprototyp. Modelleringsarbete utfördes i SolidWorks, där olika komponenter och modifieringarvisualiserades och testades innan de integrerades i gipsskivlyften. Den slutliga prototypenintegrerar funktioner som möjliggör ”tilt” och lyft av taktält vilket minskar behov av manuellalyft och därmed risken för fysiska skador som konsekvens av överbelastningar.Prototypen testades och utvärderades där resultaten visade en förbättring av ergonomi ochanvändarvänlighet under lyft av taktält, underlättar förflyttning av taktält mellan fordon ochförvaring samtidigt som den kunde förvaras tillsammans med taktält med minimal påverkanpå krav av utrymme.Sammanfattningsvis föreslår arbetet ytterligare hållfasthetstester och undersökning av bättrelämpade hissfunktioner för framtida utveckling för att förbättra säkerheten ochlyftanordningens effektivitet.
122

Analýza rozložení teplotního profilu v pájecí peci pomocí systémů CAE / Analysis of the distribution of the temperature profile in the furnace brazing using CAE systems

Stručovský, Aleš January 2013 (has links)
The aim of this project is using the CAE system to analyze the distribution of the temperature profile brazing furnace DIMA 0180. To create the model is used SolidWorks Premium 2012. The simulation is performed using the Flow Simulation. This work builds on the knowledge diploma thesis by Martin Procházka titled The effect of different heat capacities and components on the longitudinal temperature profile for reflow soldering. We start from the knowledge of heat transfer, especially of heat conduction and radiation, which appear in the furnace.
123

Simulace přestupu tepla v nízkonapěťovém rozváděči MNS / Simulation of Heat Transfer in Low-Voltage Switchboard MNS - Optimization of Heat Transfer into The Switchboard

Czudek, Aleš January 2015 (has links)
The thesis includes diagnostics temperature field of industrial low voltage. Place of origin, flow and heat transfer are important aspects in the design of the switchgear, especially in terms of proper equipment layout. The correctness of the design of the switchgear is verified by measuring the practical temperature field during testing or in work mode. To determine the temperature profile, it is necessary to measure the temperature at various points of the switchgear, either contact or contactless method. Measurements are performed on standardized low voltage switchboards, which are located power elements. The goal is to replace costly and time-consuming field testing switchgear efficient simulation of the temperature field mathematical model developed switchboards.
124

Výpočet tepelného pole rozvaděče UniGear 500R / Calculation of heat and force field UniGear ZS1

Mokrý, Lukáš January 2015 (has links)
The aim of my work is to describe high-voltage switchgear type UniGear 500R, which is part of UniGear switchgears family. I will focus on heating issue of one 500R unit and its parts during operation. Maximum values of this heating is limited by standards and can´t be exceed to ensure safe and reliable operation. That is why the heating tests are necessary part of designing and developing switchgears. Calculation will be made by two different ways. First is classic one-pole heating net method and second is numerical simulation in Solidworks flow simulation program. Except the theoretical description there will be presented also used 3D model and explanation of both method, used to calculation and simulation. Last point of this work is measuring of this type of switchgear and getting real data. The main point there is to compare measured values with values calculated and decide if is possible to simulate tests with appropriate accuracy. Then would be also possible to substitute the real test in laboratory, which costs many thousand crowns and takes lots hours of time. This work is collaborated with EJF division of ABB Company, where I am employed. Heating issues in this company is always on process, because of developing and improving of their products. So this work could be helpful in this field. ABB provides all materials needed, especially technical catalogues, 3D model and final values from laboratory measuring. Support from college faculty is mainly in study consultations and proposing of calculations making. In the end of work will be make final comparison and evaluation of achieved results.
125

Development and assessment of CFD models including a supplemental program code for analyzing buoyancy-driven flows through BWR fuel assemblies in SFP complete LOCA scenarios

Artnak, Edward Joseph 31 January 2013 (has links)
This work seeks to illustrate the potential benefits afforded by implementing aspects of fluid dynamics, especially the latest computational fluid dynamics (CFD) modeling approach, through numerical experimentation and the traditional discipline of physical experimentation to improve the calibration of the severe reactor accident analysis code, MELCOR, in one of several spent fuel pool (SFP) complete loss-of-coolant accident (LOCA) scenarios. While the scope of experimental work performed by Sandia National Laboratories (SNL) extends well beyond that which is reasonably addressed by our allotted resources and computational time in accordance with initial project allocations to complete the report, these simulated case trials produced a significant array of supplementary high-fidelity solutions and hydraulic flow-field data in support of SNL research objectives. Results contained herein show FLUENT CFD model representations of a 9x9 BWR fuel assembly in conditions corresponding to a complete loss-of-coolant accident scenario. In addition to the CFD model developments, a MATLAB based control-volume model was constructed to independently assess the 9x9 BWR fuel assembly under similar accident scenarios. The data produced from this work show that FLUENT CFD models are capable of resolving complex flow fields within a BWR fuel assembly in the realm of buoyancy-induced mass flow rates and that characteristic hydraulic parameters from such CFD simulations (or physical experiments) are reasonably employed in corresponding constitutive correlations for developing simplified numerical models of comparable solution accuracy. / text
126

Design, Modeling, and Testing of a Force Feedback Haptic Device for Simulated Robot Interaction / Design, modellering, och test av en kraftåterkopplad haptisk pryl för simulerad robot interaktion

Lindström, Patrik January 2023 (has links)
Haptic feedback is a growing phenomenon that incorporates the sense of touch through tactile sensations such as vibrations, electrical signals, air pressure, and sound waves or through force feedback, which employs torques and/or forces to replicate the pressure and weight of a simulated object. Utilizing haptic technology establishes a communication bridge between the user and the technical component, enhancing the user's understanding of the technical component's surroundings. This thesis focuses on designing a force feedback haptic device with an impedance control strategy, enabling the imposition of dynamic behavior during simulated robot interactions. Impedance control is a commonly employed approach in haptic devices, utilizing a mass-spring-damper model to vary stiffness, damping, and inertia levels, thereby simulating realistic forces and torques in master-slave interactions.  Initially, a haptic device resembling the shape of a Delta robot was designed using Solidworks, with size and weight distribution serving as the primary design considerations. Subsequently, the device was further represented using a generic robot description format, incorporating the design's joints and links. This representation was then paired with kinematic connections delineating the robot's motion and dynamic matrices to simulate the robot's movement. Alongside the integration of an impedance control strategy, simulations were conducted to emulate robot interactions. These simulations tested the system under various conditions, including scenarios with and without introduced torque disturbances. Including torque disturbances was intended to enhance the simulation's realism and assess the impact of impedance control parameter choices on the system's behavior. In summary, the research concludes how a closed-chain robot, the Delta robot, can be modeled as a haptic device with an impedance control strategy, offering valuable guidance for future research. / Haptisk återkoppling är ett växande fenomen som integreras i allt fler användningsområden. Genom att återskapa känslan av att röra vid eller interagera med föremål, antingen genom att simulera taktila sensationer som vibrationer, elektriska signaler, lufttryck och ljudvågor eller genom att återge kraftåterkoppling till användaren, kan användarens förståelse för tekniska komponenter och deras omgivning öka. Kraftåterkoppling möjliggör imitation av tryck och vikt hos simulaterade objekt, vilket förbättrar realismen i användarupplevelsen. Detta examensarbete har inriktat sig på att designa en haptisk pryl med kraftåterkoppling och en styrmekanism baserad på impedanskontroll. Genom att implementera impedanskontroll kan dynamiska beteenden inkorporeras i systemet genom varierande styrka, dämpning och tröghet. Dessa impedansparametrar möjliggör realistiska simuleringar av kraft och vridmoment i samband med virtuella robotinteraktioner. Först utformades en haptisk pryl som efterliknar formen av en Delta-robot med hjälp av CAD-programmet Solidworks. Här var storlek och viktfördelning primära överväganden i designprocessen. Därefter representerades enheten genom en generisk robotbeskrivning som inkluderade dess leder och länkar. Denna representation kopplades sedan ihop med kinematiska samband som reglerade enhetens rörelse. Tillsammans med integreringen av impedanskontrollstrategin genomfördes simuleringar som efterliknade robotinteraktioner. Dessa simuleringar omfattade olika scenarier, inklusive de med vridmomentsstörningar och de utan. Syftet med att inkludera vridmomentsstörningar var att öka realismen i simuleringen och utvärdera påverkan av valda parametrar för impedanskontrollen på systemets beteende. Sammanfattningsvis har detta arbete resulterat i utformningen av en haptisk pryl med kraftåterkoppling, som efterliknar en Delta-robot. Prylen har modellerats som en trädstruktur, med kinematiska samband som sammanfogar dess ändnoder. Det här arbetet har bidragit till kunskapen om hur realistiska haptiska interaktioner kan skapas och öppnat möjligheter för framtida forskning och utveckling inom detta område.

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