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EN
Structural design analyses of industrial dye mixing machines, concerning mixing impeller geometries, mixing performances, and power requirements aren’t generally of scientific quality. Our aim is to propose a practical method for minimizing execution time, using parametric design. In this study, Visual Basic API codes are developed in order to model the impellers in SolidWork,sup>R software, and then flow analyses are conducted. Thus, velocity values and moment/torque values required for mixing operation are determined. This study is carried out for different shaft rotational speeds and different impeller diameters. Flow trajectories are obtained. After that, frequency analyses are conducted and natural frequency values are obtained. In the scope of this study, two different impeller types are investigated.
EN
In the paper, a procedure for precise and expedited design optimization of unequal power split patch couplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to the circuit operating at the requested frequency and featuring a required power split. At the same time, the design process is supposed to be computationally efficient. The proposed methodology involves two types of auxiliary models (surrogates): an inverse one, constructed from a set of reference designs optimized for particular power split values, and a forward one which represents the circuit S-parameter gradients as a function of the power split ratio. The inverse model directly yields the values of geometry parameters of the coupler for any required power split, whereas the forward model is used for a post-scaling correction of the circuit characteristics. For the sake of illustration, a 10-GHz circular sector patch coupler is considered. The power split ratio of the structure is re-designed within a wide range of -6 dB to 0 dB. As demonstrated, precise scaling (with the power split error smaller than 0.02 dB and the operating frequency error not exceeding 0.05 GHz) can be achieved at the cost of less than three full-wave EM simulations of the coupler. Numerical results are validated experimentally.
EN
This study focuses on the development of an interface for gesture control and Boolean operation of 3D objects in 3D computer-aided design (CAD). Although mouse and keyboard have been mainly used as computer input devices, novel computer interfaces are becoming increasingly popular with rapid development of computer technologies. Among several computer interfaces, the gesture interface is well-known as an system operable through the natural human behavior. However, the application to 3D CAD has been scarcely studied so far. From the backgrounds, a simple gesture interface was developed to operate a 3D object in 3D CAD. Leap Motion Controller (LMC) was used as a motion sensor device. A dialog-based graphical user interface (GUI) was also created for the parameter setting. As a result, several operational functions could be successfully executed through various hand-finger motions. Moreover, the system enabled us to experience an intuitive interaction with 3D CAD. Then, the several demonstrations were performed to identify the recognition characteristics of the gesture interface. The differences in the recognition rate were revealed as the results. Especially, it confirmed that a combination of static and dynamic gestures could help to enhance the recognition rate in the gesture interface using LMC. In accordance with the findings, the functions for Boolean operation were also implemented for the manipulation of a 3D object, such as extrusion and hole making.
PL
Hale stalowe należą do jednego z najczęściej stosowanych typów konstrukcji stalowych. Podlegają one obciążeniom głównie od ciężaru własnego, śniegu i wiatru. Przy ich obliczaniu coraz częściej wykorzystuje się komputerowe wspomaganie projektowania. Oprogramowanie to służy do tworzenia modelu geometrycznego, generacji obciążeń, wyznaczania sił wewnętrznych oraz sprawdzania stateczności elementów. W artykule przedstawiono sposób generowania obciążeń od śniegu i wiatru na konstrukcję portalowej hali stalowej. Wykorzystano program Autodesk Robot Structural Analysis Professional.
EN
Steel halls are one of the most popular types of steel structures. Their loads come mainly from their own weight, wind and snow. Computer-aided design is used more and more commonly to design such types of structures. This software is applied for creating a geometrical model, generating loads, deter mining internal forces and checking the stability of elements. In this paper, the method of generating (simulation) of steel hall loads from wind and snow is presented. The computer software Autodesk Robot Structural Analysis Professional was used for this purpose.
EN
Finding an acceptable compromise between various objectives is a necessity in the design of contemporary microwave components and circuits. A primary reason is that most objectives are at least partially conflicting. For compact microwave structures, the design trade-offs are normally related to the circuit size and its electrical performance. In order to obtain comprehensive information about the best possible trade-offs, multi-objective optimization is necessary that leads to identifying a Pareto set. Here, a framework for fast multi-objective design of compact micro-strip couplers is discussed. We use a sequential domain patching (SDP) algorithm for numerically efficient handling of the structure bandwidth and the footprint area. Low cost of the process is ensured by executing SDP at the low-fidelity model level. Due to its bi-objective implementation, SDP cannot control the power split error of the coupler, the value of which may become unacceptably high along the initial Pareto set. Here, we propose a procedure for correction of the S-parameters’ characteristics of Pareto designs. The method exploits gradients of power split and bandwidth estimated using finite differentiation at the patch centres. The gradient data are used to correct the power split ratio while leaving the operational bandwidth of the structure at hand intact. The correction does not affect the computational cost of the design process because perturbations are pre-generated by SDP. The final Pareto set is obtained upon refining the corrected designs to the high-fidelity EM model level. The proposed technique is demonstrated using two compact microstrip rat-race couplers. Experimental validation is also provided.
PL
Jednym z najbardziej rozpowszechnionych sposobów wytwarzania wyrobów z blach jest tłoczenie, obejmujące cięcie, gięcie i kształtowanie blach. Kwalifikacja materiałów wsadowych do procesów tłoczenia ciągle stanowi problem wytwórców pojazdów i jest tematem licznych opracowań [1, 3, 13, 15, 16, 18, 20-22]. Zalety tłoczenia, takie jak: niska masa i cienkościenność wytłoczek, wysoka dokładność odwzorowania geometrii detalu, automatyzacja i robotyzacja procesu wytwarzania stanowią o atrakcyjności tej technologii. Jednakże występują zjawiska, które ograniczają znacząco możliwości przetwarzania blach w złożonym stanie naprężeń i odkształceń umożliwiającym wykonanie danego detalu. Stąd projektowanie procesów tłoczenia nie może się już obyć bez wspomagania komputerowego projektowania wytłoczek. Dla konwencjonalnych sposobów kształtowania blach i prostego kształtu wytłoczek z dużą dokładnością przewidywane są zjawiska ograniczające tłoczenie, jak fałdowanie i pocienianie blachy prowadzące do jej pęknięcia. W tym zakresie wykorzystywane są programy komputerowe do modelowania i symulacji numerycznej metodą elementów skończonych [16, 20, 22] oraz charakterystyki właściwości mechanicznych materiałów wsadowych i graniczne krzywe tłoczenia blach wsadowych. Natomiast projektowanie niekonwencjonalnych sposobów tłoczenia, jak kształtowanie hydromechaniczne, czy tłoczenie na gorąco, jest stale doskonalone ponieważ pozostaje ciągle nierozpoznanym zagadnieniem w zakresie skutecznego prognozowania zjawisk ograniczających tłoczenie. Do modelowania numerycznego tych złożonych zagadnień kształtowania blach stosuje się różne programy komputerowe. W tym opracowaniu przedstawiono wybrane przykłady wykorzystania oprogramowania ETA / Dynaform 5.9 [2] do przewidywania zjawisk ograniczających kształtowanie blach w konwencjonalnym tłoczeniu wytłoczki poszyciowej z blachy o wysokiej wytrzymałości oraz w niekonwencjonalnym kształtowaniu cieczą tej samej blachy na wytłoczkę osiowo-symetryczną.
EN
One of the most common methods of manufacturing sheet metal products is stamping, including cutting, bending and shaping of sheets. The qualification of input materials for stamping processes is still a problem for vehicle manufacturers and is the subject of numerous studies [1, 3, 13, 15, 16, 18, 20- 22]. The advantages of pressing such as: low mass and thin-walled drawpieces, high accuracy of the geometry of the detail, automation and robotization of the manufacturing process are the attractiveness of this technology. However, there are phenomena that significantly limit the possibility of processing sheets in a complex state of stresses and strains enabling the creation of a particular detail. Hence, the design of stamping processes can no longer be used without the support of computerized design of stampings. For conventional methods of forming sheets and the simple shape of drawpieces, phenomena limiting the pressing, such as folding and thinning of the sheet leading to its cracking, are predicted with great accuracy. In this area, computer programs for modeling and numerical simulation are used applying the finite element method [16, 20, 22] and characteristics of mechanical properties of charge materials and forming limit curves of charge sheet blank pressing. On the other hand, the design of unconventional pressing methods, such as hydroforming or hot stamping, is constantly improved because it remains an unrecognized issue in the field of effective forecasting of phenomena limiting the pressing. Numerous computer programs are used for numerical modeling of these complex issues of sheet forming. This paper presents selected examples of the use of ETA / Dynaform 5.9 software [2] for predicting phenomena limiting sheet metal forming in conventional pressing of a high-strength sheet metal stamping and unconventional shaping of the same sheet into an axially symmetrical drawpiece.
7
Content available remote Projektowanie przekładników prądowych klasy S
PL
W artykule opisano możliwość zastosowania programu komputerowego do projektowania przekładników prądowych klasy S. Przedstawiono wyniki praktycznej weryfikacji przyjętego rozwiązania poprzez porównanie błędu prądowego i kątowego dla modelu cyfrowego i fizycznego badanego przekładnika prądowego.
EN
The paper presents mathematical model and its application in design process of S class current transformers. The accuracy of the designed method was verified by comparing the current error and phase displacement of digital and physical models of the tested CT.
8
Content available remote Ramy portalowe z ryglem ażurowym – projektowanie wspomagane komputerowo
PL
Stalowe ramy portalowe z ryglem ażurowym są jednym z układów konstrukcyjnych hal stalowych. Do sprawdzania stateczności poszczególnych elementów wchodzących w skład omawianych konstrukcji powszechnie stosowane jest oprogramowanie komputerowe bazujące na metodzie elementów skończonych. W artykule przedstawiono porównanie wyników uzyskanych z obliczeń wykonanych za pomocą programu Robot Structural Analysis Professional firmy Autodesk i ACB+ z wynikami wstępnego (uproszczonego) doboru rygla przedstawionego w [3].
EN
Steel portal frames with rafter as a castellated beam are one of the structure types of steel halls. Computer software based on the finite element method is often used to check resistance and stability of frames and their elements. The comparison of the calculations results of frames has been presented in the paper. The calculations have been made taking into consideration steel portal frames: the span of the frame – 15 m, the height of the frame – 4.5 m. Two kinds of software have been taken into account: Autodesk’s Robot Structural Analysis and ACB+.
EN
This work examines the reduced-cost design optimization of dual- and multi-band antennas. The primary challenge is independent yet simultaneous control of the antenna responses at two or more frequency bands. In order to handle this task, a feature-based optimization approach is adopted where the design objectives are formulated on the basis of the coordinates of so-called characteristic points (or response features) of the antenna response. Due to only slightly nonlinear dependence of the feature points on antenna geometry parameters, optimization can be attained at a low computational cost. Our approach is demonstrated using two antenna structures with the optimum designs obtained in just a few dozen of EM simulations of the respective structure.
EN
A modern main rotor, dedicated to the ultralight helicopter, has been designed and optimised. Due to assumed simplicity of the rotor design and taking into account some technological constraints, the principal purpose of the presented research was to design a dedicated airfoil which, when applied on the main-rotor blades, would influence satisfactory improvement in a performance of the ultralight helicopter, especially in fast flight. The design and optimisation process has been supported by a computational methodology. The in-house software has been used for direct and inverse design of shapes of the rotor-blade airfoils. Aerodynamic properties of the airfoils as well as the helicopter main rotor were evaluated based on both the two-dimensional and three-dimensional flow simulations conducted using the ANSYS FLUENT software that was used to solve U/RANS equations. Based on the results of conducted computational simulations of fast flight of the ultralight helicopter, it can be concluded that the newly designed main rotor, compared to the baseline, may give certain improvement in helicopter performance in fast flight. In addition, the application of this newly designed rotor may lead to increase of a maximum speed of the helicopter flight, due to the greater lift force achievable by this rotor on the retreating blade, which is favourable from point of view of keeping of a lateral balance of the helicopter in fast flight.
PL
W artykule omówiono konstrukcję śrubowej sprężyny naciskowej z użyciem generatora dostępnego w Inventorze. Wartości obciążeń niezbędne do wprowadzenia do modułu obliczeniowego generatora uzyskano metodami analitycznymi. Omówiono i przeanalizowano pracę generatora. Dokonano weryfikacji wyników obliczeń wytrzymałościowych otrzymanych podczas pracy modułu obliczeniowego generatora, z uzyskanymi w drodze obliczeń konwencjonalnych.
EN
The article discussed the design of the helical compression spring using generator available in Inventor. Necessary Load values for the calculation module of the generator obtained by analytical methods. Work of the generator was discussed and analyzed. Was verified the results of strength calculations obtained during operation calculation module generator with those obtained by conventional calculation.
PL
W artykule omówiono konstrukcję przykładowej przekładni pasowej z wykorzystaniem generatora dostępnego w aplikacji Inventor. Wykonano niezbędne obliczenia metodą analityczną. W obliczeniach uwzględniono wytyczne i zalecenia zawarte w normach. Omówiono działanie generatora przekładni z paskami klinowymi. Dokonano weryfikacji pracy generatora i otrzymanych wyników poprzez porównanie z wynikami obliczeń wykonanych metodami klasycznymi.
EN
The article discussed the design of an exemplary V-belt drive using a generator available in Inventor. Necessary calculations was made with analytical method. In the calculation were taken into account the guidelines and recommendations contained in the standards. Discussed the work of V-belt gear. Was verified the generators work and obtained results by comparing the results of calculations performed by classical methods.
EN
Purpose: This work aims to present a methodology developed for dimensional analysis of removable partial dentures, following a route with a model manufactured by additive manufacture and a further casting process of a Co-Cr alloy part. Design/methodology/approach: The method for designing and manufacturing removable partial dentures (RPD) is focused on their completely virtual design. They are manufactured with resin additive manufacturing chrome-cobalt cast alloys. A 3D image correlation scanner was used for dimensional and geometrical tolerance analysis. Findings: The prostheses manufactured by CAD-CAM route are more accurate than conventional ones, but they suffer distortion during the casting process. This distortion did not interfere with the patient's well-being or with the adaptation to the prosthesis. Research limitations/implications: The technique presented herein paper allows preparing better fitting prosthesis. Providing the best comfort and masticatory power. Practical implications: Improving the precision in the manufacturing process of a removable partial denture is very important for professional dentists and their patients. Originality/value: The proposed technique and the work approach provide the prosthesis preparation with shorter ambulatory time in addition to greater comfort to the patient.
15
Content available remote Analityczna metoda projektowania łuków odwrotnych
PL
W pracy przedstawiono nową metodę projektowania rejonu zmiany kierunku trasy kolejowej, dostosowaną do techniki Mobilnych Pomiarów Satelitarnych. Metoda ta może się okazać szczególnie przydatna wówczas, gdy obydwu prostych kierunków trasy nie można połączyć w sposób elementarny, stosując łuk kołowy z krzywymi przejściowymi; dotyczy to również zastosowania łuku koszowego. Jedynym rozwiązaniem staje się wówczas wprowadzenie do układu geometrycznego dwóch łuków kołowych o przeciwnych znakach krzywizny, czyli zastosowanie łuku odwrotnego. Rozwiązanie problemu projektowego wykorzystuje zapis matematyczny i polega na wyznaczeniu uniwersalnych równań opisujących całość układu geometrycznego. Odbywa się to sekwencyjnie, obejmując kolejne fragmenty tegoż układu. Zaprezentowana metoda została zilustrowana odpowiednim przykładem obliczeniowym.
EN
The paper deals with a new approach relating to the design of the region of railway track direction alteration adapted to Mobile Satellite Measurements technique. The method may be particularly useful in situation when both the straights of the route directions cannot be connected in an elementary way using a circular arc with transition curves; this also refers to the application of a compound curve. Thus the only solution becomes the application of two circular arcs of opposite curvature signs to the geometric system, i.e. the use of an inverse curve. The solution of the design problem takes advantage of a mathematical notation and concentrates on the determination of universal equations describing the entire geometric system. This is a sequential operation involving successive parts of the system. The presented method has been illustrated by appropriate calculation examples.
PL
Artykuł przybliża specyfikę modeli BIM na tle ewolucji technik komputerowego wspomagania projektowania CAD. Wskazuje na uwarunkowania i trudności związane z wdrażaniem technologii BIM w projektach infrastrukturalnych i modelowania mostów. Pokazuje fragmenty zbudowanego modelu BIM wiaduktu drogowego w Gliwicach. Na koniec omówiono podstawowe założenia systemu AR i jego potencjalne możliwości wykorzystania w zarządzaniu obiektami mostowymi.
EN
The paper describes two new technologies: Building Information Modelling (BIM) and Augmented Reality (AR), which will be the basis of a revolution in the processes of designing, construction and management of transport infrastructure, including bridges, in the coming years. The paper introduces the specificity of BIM models on the background of the evolution of techniques for computer-aided design (CAD). It points out the conditions and difficulties in implementing the BIM technology in infrastructure projects and the modelling of bridges. It also presents the selected details of the created BIM model of a long viaduct in Gliwice, which will be used in future research project as a testing ground for a new system designed for the inspection of bridges based on augmented reality. The basic assumptions of the AR system and its potential use in the management of bridge structures are discussed.
PL
Przedstawiono koncepcję rozwiązania konstrukcyjnego roweru w stylu retro. Zaprezentowano budowę i zasadę działania napędu dwubiegowego w postaci zespołu przekładni trójdrożnych umieszczonego w piaście koła przedniego. Opisano sposób przygotowania modelu do wykonania prototypu napędu za pomocą technik RP.
EN
This paper presents a design solution concept in the retro style bike. The work shows the construction and operating principle of the two-speed drive in the form of a three-way gearbox assembly which is placed in the hub of the front wheel. Moreover, there is given a method of preparing a drive model for a prototype manufacturing by RP methods.
EN
Innovative exhaust system for light turboprop airplane has been developed and optimised. Apart from the basic function of removing exhaust from turboprop engine, the system supports cooling of the engine bay. To do this, the system removes hot air from the engine bay, utilising the ejector-pump effect, where the exhaust stream generates under-pressure, sucking the hot air through the ejector slot and removes the air together with the exhaust gases. The design and optimisation of the exhaust system has been conducted based on computational methods of Computer-Aided Design and Optimisation and Computational Fluid Dynamic. Three-dimensional analysis of flow around the airplane (including effect of propeller) and inside the exhaust system was conducted by application of URANS solver ANSYS FLUENT. Using these software the trajectories of exhaust particles, both inside the exhaust ducts and outside the airplane, have been determined. Parametric model of the designed exhaust system has been developed using the in-house software PARADES. As design parameters the diameter, length and direction of exhaust ducts as well as few parameters describing a shape of the ejector, have been established. The optimisation process aimed at designing of the exhaust system, which removes the exhaust gases possibly far away from the airframe, especially during a descent flight of the airplane. Additional objectives were maximisation of the mass flow rate of hot air sucked through the ejector and minimisation of the drag force generated by external part of the exhaust system. The optimised exhaust system should have also fulfilled requirements of permissible total-pressure losses inside the exhaust ducts. The optimised exhaust system has been implemented on the light turboprop airplane and validated during flight tests.
19
Content available remote Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics
EN
Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.
EN
A new Computer-Aided Design approach is introduced for design of steel castings taking into account the feeding ability in sand moulds. This approach uses the geometrical modeling by a CAD-program, in which the modul “Castdesigner” is implemented, which includes the feeding models of steel castings. Furthermore, the feeding ability is guaranteed immediately during the design by an interactive geometry change of the casting cross section, so that a directional feeding of the solidifying casting from the installed risers is assured.
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