853 resultados para 3D Geometry


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Tämä diplomityö tehtiin Valmet Technologies Oy:n Järvenpään toimipisteelle. Työn tavoitteena oli tutkia miten pituusleikkureiden 3D-suunnittelua voidaan tehostaa hyödyntämällä uuden 3D-CAD -järjestelmän ominaisuuksia optimaalisesti. Työ koostuu teoriaosuudesta, haastattelututkimuksesta sekä käytännön osuudesta. Teoriaosuudessa perehdytään pituusleikkurin toimintaan ja rakenteeseen, 3D-suunnittelun teoriaan sekä CATIA-järjestelmään. Teoriaosuudessa etsitään myös uusia näkökulmia 3D-suunnitteluun. Haastattelututkimuksessa kartoitetaan nykyinen suunnitteluprosessi, suunnittelun kehitettäviä kohteita, sekä käytössä olevia suunnittelumenetelmiä, jotka ovat todettu toimiviksi. Haastattelututkimuksessa haastatellaan Valmet Technologies Oy:n Järvenpään toimipisteessä työskenteleviä pituusleikkureiden pääsuunnittelijoita sekä heidän esimiehiään. Lisäksi erillisten haastattelujen avulla kerätään kokemuksia CATIA V6 -ohjelmiston käytöstä sekä suunnitteluohjelmiston vaihtumisesta. Käytännön osuuden tavoitteena on arvioida pituusleikkurin parametroitujen mallirakenteiden siirtämiseen sekä korjauksiin kuluvia aikamääriä kyseisiin toimenpiteisiin tarvittavien resurssien määrittämiseksi. Käytännön osuudessa siirretään kaksi Valmet OptiWin Drum Compact -pituusleikkurin parametroitua osakokonaisuutta uuteen CAD-järjestelmään ja niille suoritetaan tarvittavat korjaustoimenpiteet Tutkimuksen tulosten perusteella yhteisen mallinnusmetodologian puuttuminen on merkittävin kehityskohde suunnittelun kehittämisessä. Lopuksi luotiin kehitysehdotukset sekä implementointisuunnitelma, joiden avulla pituusleikkureiden 3D-suunnittelua voidaan kehittää ja CATIA V6 -ohjelmisto voidaan ottaa käyttöön tehokkaasti.

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Additive manufacturing (shortened as AM), or more commonly 3D printing, consists of wide variety of different modern manufacturing technologies. AM is based on direct printing of a digital 3D model to a final product which is fabricated adding material layer by layer. This is from where term additive manufacturing has its origin. It is not only material what is added, but it is also value, properties etc. which are added. AM enables production of different and even better products compared to conventional manufacturing technologies. An estimation of potential of additive manufacturing can be gathered by considering the potential of laser cutting, which is one of the most widely used modern manufacturing technologies. This technique has been used over 40 years, and whole market around this technology is at the moment c. four billion euros and yearly growth is around 10 %. One factor affecting this success of laser cutting is that laser cutting enables radical improvements to products made of flat sheet. AM and 3D printing will do the same for three dimensional parts. Laser devices, which are at the moment used in 3D printing, are globally at the moment only around 1% of all laser devices used in any fabrication technology, so even with a cautious estimate the potential growth of at least 100 % is coming in next few years. Role of education is very important, when this kind of modern technology is industrially implemented. When both generation entering to work life and also generation who has been a while in work life understands new technology, its potential and limitations, this is the point when also product design can be rethought Potential of product design is driving force for wide use of additive manufacturing and 3D printing. Utilization of additive manufacturing and 3D printing is also opportunity for Finland and Finnish industry. This technology can save Finnish manufacturing industry. This technique has stron potential, as Finland has traditionally strong industrial know-how and good ICT knowledge.

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The purpose of conducting this thesis is to gather around information about additive manufacturing and to design a product to be additively manufactured. The specific manufacturing method dealt with in this thesis, is powder bed fusion of metals. Therefore when mentioning additive manufacturing in this thesis, it is referred to powder bed fusion of metals. The literature review focuses on the principle of powder bed fusion, the general process chain in additive manufacturing, design rules for additive manufacturing. Examples of success stories in additive manufacturing and reasons for selecting parts to be manufactured with additive manufacturing are also explained in literature review. This knowledge is demanded to understand the experimental part of the thesis. The experimental part of the thesis is divided into two parts. Part A concentrates on finding proper geometry for building self-supporting pipes and proper parameters for support structures of them. Part B of the experimental part concentrates on a case study of designing a product for additive manufacturing. As a result of experimental part A, the design process of self-supporting pipes, results of visual analysis and results of 3D scanning are presented. As a result of experimental part B the design process of the product is presented and compared to the original model.

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Three-dimensional (3D) forming of paperboard and heat sealing of lidding films to trays manufactured by the press forming process are investigated in this thesis. The aim of the work was to investigate and recognize the factors affecting the quality of heat sealing and the leak resistance (tightness) of press-formed, polymer-coated paperboard trays heatsealed with a multi-layer polymer based lidding film. One target was to achieve a solution that can be used in food packaging using modified atmosphere packaging (MAP). The main challenge in acquiring adequate tightness properties for the use of MAP is creases in the sealing area of the paperboard trays which can act as capillary tubes and prevent leak-proof sealing. Several experiments were made to investigate the effect of different factors and process parameters in the forming and sealing processes. Also different methods of analysis, such as microscopic analysis and 3D-profilometry were used to investigate the structure of the creases in the sealing area, and to analyse the surface characteristics of the tray flange of the formed trays to define quality that can be sealed with satisfactory tightness for the use of MAP. The main factors and parameters that had an effect on the result of leak-proof sealing and must be adjusted accordingly were the tray geometry and dimensions, blank holding force in press forming, surface roughness of the sealing area, the geometry and depth of the creases, and the sealing pressure. The results show that the quality of press-formed, polymer-coated paperboard trays and multi-layer polymer lidding films can be satisfactory for the use of modified atmosphere packaging in food solutions. Suitable tools, materials, and process parameters have to be selected and used during the tray manufacturing process and lid sealing process, however. Utilizing these solutions and results makes it possible for a package that is made mostly from renewable and recyclable sources to be a considerable alternative for packages made completely from oil based polymers, and to achieve a greater market share for fibre-based solutions in food packaging using MAP.

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Traduction de Wylie, rédigée par Li Shan lan ; préfaces Chinoises des deux traducteurs (1859) ; préface anglaise, écrite à Shang hai par A. Wylie (juillet 1859). Liste de termes techniques en anglais et en Chinois. Gravé à la maison Mo hai (1859).18 livres.

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Objective: Overuse injuries in violinists are a problem that has been primarily analyzed through the use of questionnaires. Simultaneous 3D motion analysis and EMG to measure muscle activity has been suggested as a quantitative technique to explore this problem by identifying movement patterns and muscular demands which may predispose violinists to overuse injuries. This multi-disciplinary analysis technique has, so far, had limited use in the music world. The purpose of this study was to use it to characterize the demands of a violin bowing task. Subjects: Twelve injury-free violinists volunteered for the study. The subjects were assigned to a novice or expert group based on playing experience, as determined by questionnaire. Design and Settings: Muscle activity and movement patterns were assessed while violinists played five bowing cycles (one bowing cycle = one down-bow + one up-bow) on each string (G, D, A, E), at a pulse of 4 beats per bow and 100 beats per minute. Measurements: An upper extremity model created using coordinate data from markers placed on the right acromion process, lateral epicondyle of the humerus and ulnar styloid was used to determine minimum and maximum joint angles, ranges of motion (ROM) and angular velocities at the shoulder and elbow of the bowing arm. Muscle activity in right anterior deltoid, biceps brachii and triceps brachii was assessed during maximal voluntary contractions (MVC) and during the playing task. Data were analysed for significant differences across the strings and between experience groups. Results: Elbow flexion/extension ROM was similar across strings for both groups. Shoulder flexion/extension ROM increaslarger for the experts. Angular velocity changes mirrored changes in ROM. Deltoid was the most active of the muscles assessed (20% MVC) and displayed a pattern of constant activation to maintain shoulder abduction. Biceps and triceps were less active (4 - 12% MVC) and showed a more periodic 'on and off pattern. Novices' muscle activity was higher in all cases. Experts' muscle activity showed a consistent pattern across strings, whereas the novices were more irregular. The agonist-antagonist roles of biceps and triceps during the bowing motion were clearly defined in the expert group, but not as apparent in the novice group. Conclusions: Bowing movement appears to be controlled by the shoulder rather than the elbow as shoulder ROM changed across strings while elbow ROM remained the same. Shoulder injuries are probably due to repetition as the muscle activity required for the movement is small. Experts require a smaller amount of muscle activity to perform the movement, possibly due to more efficient muscle activation patterns as a result of practice. This quantitative multidisciplinary approach to analysing violinists' movements can contribute to fuller understanding of both playing demands and injury mechanisms .

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Impurity free eluission spectra of HCCCHO and DCCCHO have been rephotographed using the electronic-energy-exchange method with benzene as a carrier gas. The near ultraviolet spectra of ReeCHO and DCCCHO were photographed in a sorption under conditions of high resolution with absorption path lengths up to 100 meters. The emission and absorption spectra of Propynal resulting from 3 n 1 t 1\ - A excitation has been reanalyzed in som.e detail. Botrl of the eH out-of-plane wagging modes were found to have negative anharmonicity. A barrier height of 56.8/0.0 cm- 1 and a nonplanar oft , , equilibrium angle of 17 3 /30 are calculated for the V 10/ lJ 11 modes. The in-plane and out-of-plane v1. brational modes in the 3A." and 1a~. ' elec ronic states of Propynal were subjected to a normal coordinate treatment in the approximat :on of tIle Urey-Bradley force field. From the relative oscillator strengths of the trans1·t1·0ns connect i ng t he v ibrat1•0n1ess lA' , state and t,he V1· bron1·C 3· if levels of the A state, the differences in equilibrium configuration were evaluated from an approximate Franck-Condon analysis based on the ground state normal coordinates. As this treatment gave 512 possible geometrical structures for the upper state, it 4 was necessary to resort to a comparison of the observed and calculated moments of inertia along with chemical intuition to isolate the structure. A test of the correctness of the calculated structure change and the vibrational assignment was raade by evaluating the intensities of the inplane and out-oi-plane fundarnental, sequence, and cross sequellce transitions y the exact Franck-Condon method.

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Passive solar building design is the process of designing a building while considering sunlight exposure for receiving heat in winter and rejecting heat in summer. The main goal of a passive solar building design is to remove or reduce the need of mechanical and electrical systems for cooling and heating, and therefore saving energy costs and reducing environmental impact. This research will use evolutionary computation to design passive solar buildings. Evolutionary design is used in many research projects to build 3D models for structures automatically. In this research, we use a mixture of split grammar and string-rewriting for generating new 3D structures. To evaluate energy costs, the EnergyPlus system is used. This is a comprehensive building energy simulation system, which will be used alongside the genetic programming system. In addition, genetic programming will also consider other design and geometry characteristics of the building as search objectives, for example, window placement, building shape, size, and complexity. In passive solar designs, reducing energy that is needed for cooling and heating are two objectives of interest. Experiments show that smaller buildings with no windows and skylights are the most energy efficient models. Window heat gain is another objective used to encourage models to have windows. In addition, window and volume based objectives are tried. To examine the impact of environment on designs, experiments are run on five different geographic locations. Also, both single floor models and multi-floor models are examined in this research. According to the experiments, solutions from the experiments were consistent with respect to materials, sizes, and appearance, and satisfied problem constraints in all instances.