Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.

Organisations comprise human and technical systems that typically perform a variety of business, engineering and production roles. Human systems comprise individuals, people groups and teams that work systematically to conceive, implement, develop and manage the purposes of any enterprise in response to customer requirements. Recently attention has been paid to modelling aspects of people working within production systems, with a view to improving: production performance, effective resource allocation and optimum resource management. In the research reported, graphical and computer executable models of people have been conceived and used in support of human systems engineering. The approach taken has been to systematically decompose and represent processes so that elemental production and management activities can be modelled as explicit descriptions of roles that human systems can occupy as role holders. First of all, a preliminary modelling method (MM1) was proposed for modelling human systems in support of engineering enterprise; then MM1 was implemented and tested in a case study company 1. Based on findings of this exploratory research study an improved modelling method (MM2) was conceived and instrumented. Here characterising customer related product dynamic impacts extended MM1 modelling concepts and methods and related work system changes. MM2 was then tested in case study company 2 to observe dynamic behaviours of selected system models derived from actual company knowledge and data. Case study 2 findings enabled MM2 to be further improved leading to MM3. MM3 improvements stem from the incorporation of so-called DPU (Dynamic Producer Unit) concepts, related to the modelling of human and technical resource system components . Case study 4 models a human system for targeted users i.e. production managers etc to facilitate analysis of human configuration and also cost modelling. Modelling approaches MM2, MM3 and also Case Study 4 add to knowledge about ways of facilitating quantitative analysis and comparison between different human system configurations. These new modelling methods allow resource system behaviours to be matched to specific, explicitly defined, process-oriented requirements drawn from manufacturing workplaces currently operating in general engineering, commercial furniture and white goods industry sectors.

Today, discrete event simulation is the only reliable tool for detailed analysis of complex behaviors of modern manufacturing systems. However, building high fidelity simulation models is expensive. Hence, it is important to improve the simulation modeling productivity. In this research, we explore two approaches for the improvement of simulation modeling productivity. One approach is the Virtual Factory Approach, using a general-purpose model for a system to achieve various simulation objectives with a single high fidelity model through abstraction. The other approach is the Reference Model Approach, which is to build fundamental building blocks for simulation models of any system in a domain with formal descriptions and domain knowledge. In the Virtual Factory Approach, the challenge is to show the validity of the methodology. We develop a formal framework for the relationships between higher fidelity and lower fidelity models, and provide justification that the models abstracted from a higher fidelity model are interchangeable with various abstract simulation models for a target system. For the Reference Model Approach, we attempt to overcome the weak points inherited from ad-hoc modeling and develop a formal reference model and a model generation procedure for discrete part manufacturing systems, which covers most modern manufacturing systems.

The traditional approaches to training surgeons are becoming increasingly difficult to apply to modern surgical procedures. The development of Minimally Invasive Surgery (MIS) techniques demands new and complex psychomotor skills, and means that the apprentice-based system described by 'see one, do one, teach one' can no longer be expected to fully prepare surgeons for operations on real patients, placing patient safety at risk. The use of cadavers and animals in surgical training raises issues of ethics, cost and anatomical similarity to live humans. Endoscopic sinus surgery involves further risk to the patient due to the proximity of vital structures such as the brain, eyes, optic nerve and internal carotid artery. In recent years, simulation has been used to overcome these problems, exposing surgeons to complex procedures in a safe environment, similarly to its use in aviation. However, the cases simulated in this manner may not be customised by training staff to present desired pathology. This thesis describes the design and development of a new tool for the creation of customised cases for the training of sinus surgery. Users who are inexperienced and non-skilled in the use of three-dimensional (3D) Computer Aided Design (CAD) modelling software may use the tool to implement pathology to the virtual sinus model, which was constructed from real CT data. Swelling is applied in five directions (four horizontal, one vertical) to the cavity lining of the frontal and sphenoid sinuses. Tumours are individually customised and positioned in the frontal, sphenoid and ethmoid sinuses. The customised CAD model may then be latterly manufactured using Three-Dimensional Printing (3DP) to produce the complex anatomy of the sinuses in a full colour physical part for the realistic simulation of surgical procedures. An investigation into the colouring of the physical model is also described, involving the study of endoscopic videos to ascertain realistic shades. The program was evaluated by a group of medical professionals from a range of fields, and their feedback was taken into account in subsequent redevelopment of the program, and to suggest further work.

In current production systems, automation and handling of workpieces is often solved by use of vacuum technology. Most production systems use vacuum ejectors which generate vacuum from compressed air by means of the Venturi effect. However, producing vacuum with compressed air is significantly less efficient than using other principles. To minimize the energy costs of pneumatic vacuum generation or to make full use of the energy available, it is important that the inner contour of the nozzle is shaped precisely to suit the specific application - also the system\'s flow conduction needs to be optimal and the flow losses have to be minimized. This paper presents a method for optimally designing pneumatic vacuum generators and producing them economically even at very low lot sizes in order to keep the operation costs low and address other concerns (such as noise emissions) as well.

The diploma thesis focuses on the manufacturing order management in company. It contains examples of production systems and their analysis for optimization. During the optimization are monitored major criteria, for example: increase of production rate, resource utilization, and so on. The result of this work is a proposed solutionarising from the outputs of optimization the manufacturing system.

The goal of this final thesis is to evaluate the performance of chosen CAM software in robotic deburring of cast parts while using external tool. For this purpose, an analysis of program’s functions was carried out and toolpath-making strategies were compared. The most appropriate strategy for mentioned technology was chosen based on this analysis. The generation of a toolpath was described on the example of real part from automotive industry. In order to simulate real machining process, a model of workspace was created, proper tool with spindle was selected and a method of clamping the workpiece was designed. A postprocessor was created, and so was the robot program, after successful simulation, as a foundation for possible practical test. PowerMill software proved to be not very suitable for this kind of machining application, mainly because of high amount of time consumed during the whole process. So the original idea of replacing classical on-line programming with this software is not advised.

Context. The efficiency of manufacturing operations depends on thechoice of transportation methods within facilities. This thesis exploresthe optimal transportation strategies for centralized manufacturingoperations at Xylem’s facilities, focusing on the transition from individual painting and packaging processes to a centralized approach. Objectives. This study aims to develop a simulation model designedto investigate the optimal transportation method to a central paintingfacility. The model addresses several aspects that are crucial for anindustrial company when deciding whether centralization is feasibleand determining the best transportation method. Methods. Utilizing a combination of simulation models and decisionmaking matrices, this research analyses the performance and efficiencyof each transportation method under current and projected productionscenarios. The simulation assesses each method’s capability to handledifferent product scales efficiently while the decision matrix evaluatesbroader operational factors. Results. The study found that production variation could be optimized by different transportation methods. The results showed thatconveyor is particularly effective for small range pumps, ensuring continuous flow, which is facilitated by the lighter weights and shorterdistance between facilities. Forklifts are found to be optimal for midrange pumps, attributed to their flexibility and substantial capacity. For the third and fourth types of products, smart products and mixers, the Blue Train is identified as the most effective method, owing toits ability to support significant load capacities and due to the longerdistances between facilities. Conclusions. The study concludes that each transportation methodhas distinct advantages, tailored to the scale and specific requirementsof the products being handled. By integrating simulation models anddecision making matrices, this research provides a comprehensive approach to select the most appropriate transportation methods, therebyenhancing operational efficiency at the facilities. / Kontext. Effektiviteten i tillverkningsverksamheter beror på valet av transportmetoder inom anläggningar. Denna avhandling utforskar de optimalatransportstrategierna för centraliserade tillverkningsoperationer vid Xylemsanläggningar, med fokus på övergången från individuella målnings- och förpackningsprocesser till ett centraliserat tillvägagångssätt. Syfte. Denna studie syftar till att utveckla en simuleringsmodell avsedd attundersöka den optimala transportmetoden till en central målningsanläggning. Modellen tar upp flera aspekter som är avgörande för ett industriföretagnär det gäller att avgöra om centralisering är genomförbar och att bestämmaden bästa transportmetoden. Metoder. Genom att använda en kombination av simuleringsmodeller ochbeslutsfattandematriser analyserar denna forskning prestanda och effektivitetför varje transportmetod under nuvarande och projicerade produktionscenarier. Simuleringen bedömer varje metods förmåga att effektivt hantera olikaproduktskalor medan beslutsmatrisen utvärderar bredare operationella faktorer. Resultat. Studien fann att produktionsvariationen kunde optimeras medhjälp av olika transportmetoder. Resultaten visade att överliggande conveyorär särskilt effektiva för small rang pumpar, vilket säkerställer ett kontinuerligtflöde, vilket underlättas av de lägre vikterna och kortare avstånden mellananläggningarna. Gaffeltruckar visar sig vara optimala för pumpar i mid range,tack vare deras flexibilitet och avsevärda kapacitet. För den tredje och fjärdetypen av produkter, smarta produkter och mixers, identifieras Blå Tåg somden mest effektiva metoden, på grund av dess förmåga att stödja betydandelastkapaciteter och på grund av de längre avstånden mellan anläggningarna. Slutsatser. Studien drar slutsatsen att varje transportmetod har distinktafördelar, anpassade till skalan och de specifika kraven för de produkter somhanteras. Genom att integrera simuleringsmodeller och beslutsfattandematriser tillhandahåller denna forskning ett omfattande tillvägagångssätt föratt välja de mest lämpliga transportmetoderna, därigenom ökas operationelleffektivitet vid anläggningen.

Este trabalho apresenta um estudo dos processos de prensagem e sinterização do politetrafluoretileno (PTFE) com o objetivo principal de investigar a influência dos parâmetros desses processos na microestrutura e nas propriedades mecânicas do material após sinterização. O PTFE faz parte do grupo dos termoplásticos, mas assim como outros polímeros de alto peso molecular, apresenta elevada viscosidade no estado fundido que impede sua utilização em moldagem por injeção, e seu processamento é realizado por compactação a frio do pó polimérico seguida de sinterização. No processo de sinterização é aplicado um tratamento térmico acima da temperatura de fusão do material que é responsável por grandes deformações anisotrópicas que, por sua vez, são dependentes do histórico de carregamentos induzidos na fase de compactação. Com o objetivo de desenvolver modelos de comportamento termomecânicos para realizar simulações computacionais dessas etapas de fabricação, ensaios experimentais foram realizados para se investigar os diferentes mecanismos de evolução microestrutural e de deformações nas etapas de compactação e sinterização. O estudo experimental do processo de compactação compreendeu a realização de ensaios de compactação uniaxial (oedométrico), de compactação hidrostática em prensa isostática e ensaios triaxiais verdadeiros em um dispositivo original acoplado numa prensa triaxial com seis atuadores eletrohidráulicos. Através dos resultados obtidos dos ensaios de compactação foi possível identificar os parâmetros do modelo de Drucker-Prager/cap, disponível na biblioteca de leis de comportamento do programa de cálculo pelo método dos elementos finitos ABAQUSTM, que permitiu de simular numericamente alguns casos simples. O estudo experimental do processo de sinterização foi realizado com o auxílio de ensaios de termogravimetria (TGA), calorimetria exploratória diferencial (DSC) e ensaios de dilatometria em corpos-de-prova isótropos e anisótropos com diferentes índices de vazios. Através dos resultados obtidos destes ensaios foi possível identificar que a deformação global de sinterização é composta por uma deformação térmica reversível, uma deformação devido à mudança de fase cristalina em fase amorfa -ou vice-versa-, uma deformação devido ao fechamento dos vazios e uma deformação de recuperação. Este estudo foi realizado em dois tipos de materiais, sendo o PTFE puro e o PTFE reforçado com 5wt% de EkonolTM e 5wt% de fibras de carbono, respectivamente comercializados pelos nomes de TeflonTM 6407 e TeflonTM 6507. / The main objective of this work is to study the influence the process parameters on the microstructure and the mechanical properties of components manufactured by compaction at room temperature and sintering of polytetrafluorethylene (PTFE). Similary to other High Molecular Weight Polymers and although it belongs to the group of thermoplastic polymers, since it cannot be processed in the melt state because its very high viscosity, PTFE, is powder processed -that consists in sintering compacted powder-. Sintering corresponds to a heat treatment up to temperatures higher than the melting temprature, inducing finite deformations that are generally anistropic and dependent on the mechanical loading the material has been submitted to during the pre-compaction at room temperature. In order to develop thermo-mechanical constitutive equations that could be used during predictive numerical simulations of the whole process, different tests have been performed to study the different mechanisms that are responsible for microstructural evolutions and deformations during compaction and sintering. The experimental study of the compaction has been performed via uniaxial (oedometric) compaction tests, hydrostatic compaction tests that were made with an isostatic hydraulic press and triaxial tests that were made with and original device installed on an electrohydraulic testing machine six actuators. A \"Drucker-Prager/cap\" type elasto-plastic model -as available in the constitutiveequations library of ABAQUSTM industrial finite element software- has been identified from the results of these tests, so that a few simple cases have been numerically simulated. The experimental study of the sintering process has been performed via Thermo-Gravimetric Analyses (TGA), Differential Scanning Calorimetric analyses (DSC) and dilatometry tests that were performed on isotropic or anisotropic specimens with different values of the porosity From the results of these tests it has been possible to decompose the sintering deformation into different mechanisms, viz. a reversible thermal expansion, a strain that is linked to the transition from the crystalline phase to the amorphous phase -or vice versa-, a pore closure strain and a recovery strain. This study has been performed on a powder made of pure PTFE and a powder of PTFE filed with 5wt% EkonolTM and 5wt% of carbon fibres, respectively available as TeflonTM 6407 and TeflonTM 6507.

Este trabalho apresenta um estudo dos processos de prensagem e sinterização do politetrafluoretileno (PTFE) com o objetivo principal de investigar a influência dos parâmetros desses processos na microestrutura e nas propriedades mecânicas do material após sinterização. O PTFE faz parte do grupo dos termoplásticos, mas assim como outros polímeros de alto peso molecular, apresenta elevada viscosidade no estado fundido que impede sua utilização em moldagem por injeção, e seu processamento é realizado por compactação a frio do pó polimérico seguida de sinterização. No processo de sinterização é aplicado um tratamento térmico acima da temperatura de fusão do material que é responsável por grandes deformações anisotrópicas que, por sua vez, são dependentes do histórico de carregamentos induzidos na fase de compactação. Com o objetivo de desenvolver modelos de comportamento termomecânicos para realizar simulações computacionais dessas etapas de fabricação, ensaios experimentais foram realizados para se investigar os diferentes mecanismos de evolução microestrutural e de deformações nas etapas de compactação e sinterização. O estudo experimental do processo de compactação compreendeu a realização de ensaios de compactação uniaxial (oedométrico), de compactação hidrostática em prensa isostática e ensaios triaxiais verdadeiros em um dispositivo original acoplado numa prensa triaxial com seis atuadores eletrohidráulicos. Através dos resultados obtidos dos ensaios de compactação foi possível identificar os parâmetros do modelo de Drucker-Prager/cap, disponível na biblioteca de leis de comportamento do programa de cálculo pelo método dos elementos finitos ABAQUSTM, que permitiu de simular numericamente alguns casos simples. O estudo experimental do processo de sinterização foi realizado com o auxílio de ensaios de termogravimetria (TGA), calorimetria exploratória diferencial (DSC) e ensaios de dilatometria em corpos-de-prova isótropos e anisótropos com diferentes índices de vazios. Através dos resultados obtidos destes ensaios foi possível identificar que a deformação global de sinterização é composta por uma deformação térmica reversível, uma deformação devido à mudança de fase cristalina em fase amorfa -ou vice-versa-, uma deformação devido ao fechamento dos vazios e uma deformação de recuperação. Este estudo foi realizado em dois tipos de materiais, sendo o PTFE puro e o PTFE reforçado com 5wt% de EkonolTM e 5wt% de fibras de carbono, respectivamente comercializados pelos nomes de TeflonTM 6407 e TeflonTM 6507. / The main objective of this work is to study the influence the process parameters on the microstructure and the mechanical properties of components manufactured by compaction at room temperature and sintering of polytetrafluorethylene (PTFE). Similary to other High Molecular Weight Polymers and although it belongs to the group of thermoplastic polymers, since it cannot be processed in the melt state because its very high viscosity, PTFE, is powder processed -that consists in sintering compacted powder-. Sintering corresponds to a heat treatment up to temperatures higher than the melting temprature, inducing finite deformations that are generally anistropic and dependent on the mechanical loading the material has been submitted to during the pre-compaction at room temperature. In order to develop thermo-mechanical constitutive equations that could be used during predictive numerical simulations of the whole process, different tests have been performed to study the different mechanisms that are responsible for microstructural evolutions and deformations during compaction and sintering. The experimental study of the compaction has been performed via uniaxial (oedometric) compaction tests, hydrostatic compaction tests that were made with an isostatic hydraulic press and triaxial tests that were made with and original device installed on an electrohydraulic testing machine six actuators. A \"Drucker-Prager/cap\" type elasto-plastic model -as available in the constitutiveequations library of ABAQUSTM industrial finite element software- has been identified from the results of these tests, so that a few simple cases have been numerically simulated. The experimental study of the sintering process has been performed via Thermo-Gravimetric Analyses (TGA), Differential Scanning Calorimetric analyses (DSC) and dilatometry tests that were performed on isotropic or anisotropic specimens with different values of the porosity From the results of these tests it has been possible to decompose the sintering deformation into different mechanisms, viz. a reversible thermal expansion, a strain that is linked to the transition from the crystalline phase to the amorphous phase -or vice versa-, a pore closure strain and a recovery strain. This study has been performed on a powder made of pure PTFE and a powder of PTFE filed with 5wt% EkonolTM and 5wt% of carbon fibres, respectively available as TeflonTM 6407 and TeflonTM 6507.