Czasopismo Techniczne z. 3. Mechanika z. 3-M

Czasopismo Techniczne z. 3. Mechanika z. 3-M

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Collection items (29)


Meshing using P-method

Żakowska, Marta
Article
2008
Accuracy and efficiency of analysis carried out thanks to the FEM method mainly depends on the quality of discrete model. That is why there are many tools used in practice to create discrete models. The most often are used tools using models of h- and p-elements. The characteristic feature of discrete models using h-elements is approximation of continuous field by linear functions, or second order polynomials. In case of discrete models using p-elements approximation is carried out using higher order polynomials, which allows automatic and good mesh adaptation on these models. In the article there were presented examples of creating discrete models using h- and p-elements and illustrated differences between discrete models created using both kinds of methods. Additionally, there was presented mesh adaptation process on discrete models made by p-elements.

Genetic algorithm with additional parameter for 2-dimensional irregular shape cutting problem

Żak, Sławomir
Article
2008
The optimum cutting problems occur very frequently in various area of industry and technology. A number of algorithms were proposed, targeting solving particular variants of the aforementioned problems (guillotine cut, non-guillotine cut, etc.). In the article, we proposed and examined a genetic algorithm implementation with an additional parameter, allowing for optimization of the placement of individual elements with irregular shape profile on dimensional surface. The simulation results were presented, examining the impact of the combination of generic operators and the proposed additional parameter on the quality of the obtained results. An example of practical implementation of the examined algorithm in engineering applications is presented, thanks to the integration with the AutoDesk software package – AutoCAD 2007.

Contact interaction of resilient and cylindrical dies with initial (residual) tension

Yaretska, Natalia
Article
2008
The article deals with a mixed type task of measuring pressure of an elastic cylinder die upon a layer with initial stresses within the framework of linear elasticity theory. In general, the research was carried out for the theory of great initial (ultimate) deformations and different variants of the theory of small initial deformations with arbitrary structure of elastic potential.

Parametric 3D model of a planetary gear motor

Ulatowska, Anna
Article
2008
The paper describes solid modelling application in design and understanding the construction and working principles of gear motor. Most computer programs create engineering models via 2-D drawing, 3-D wire-frames or 3-D surface models. Complete product description, down to the proper dimensioning scheme and tolerances were impossible. This changed with the introduction of parametric modelling allows the designer to let the characteristic parameters of a product drive its design. In the case of gear designers the key dimensions that would describe the gear include diametric pitch, pressure angle, root radius, and tooth thickness. The parameters also cover key process information such as hardening specifications, quality grades, and metallurgical properties together with load classification for the given gear. In the present study a 3D model of a motor has been generated in Pro/Engineer. It can be concluded that the feature-based parametric modelling systems allow CAD/CAM/CAE software to become a more integral part of product design process.

Nurbs curves and surfaces application in CAD systems

Sikorska, Sylwia
Article
2008
Currently, B-splines and NURBS (Non-Uniform Rational B-spline) are the most popular mathematical forms for curves and surfaces representation. NURBS offer a unified mathematical form not only for representation of free-form curves and surfaces, but also for the precise representation of close-form shapes such as lines, conics, quadrics, and surfaces of revolution. In the paper application of NURBS curves and surfaces in CAD systems like Pro/Engineer Wildfire 3.0 was presented. Animation of human expressions based on the NURBS representation based on human facial anatomy was illustrated. Facial muscle movements and expressions can be simulated by modification of the weights, or moving the control points of the NURBS curves.

Analysis of efficiency of parallel computing in image processing task

Petryniak, Rafał
Article
2008
The article deals with parallel computing applied in image processing. An algorithm of edge finding was examined and analysed in tests. Each parallel approach is described in detail and the strengths and weaknesses of each are shown. Different solutions have been implemented to answer the question: "When and how to improve the efficiency of image processing?". One of the conclusions is that there is a need to build parallel image analysing algorithms to enable running them on new computers with a parallel architecture.

VRML generator of land features 3D representation based on a hypsometric map

Pasternak, Wojciech, Latała, Zbigniew
Article
2008
The paper contains an original program "KARTOGRAF 3D" enabling a 3D model of land features to be created based on the hypsometric map. 3D modelling is carried out by generating a VRML code being a digital representation of the topography. All the project is a Windows application designed for Windows and implemented in language C++ by using the IDE tool of Borland- C++ Builder RAD type [4]. Such environment was chosen because it allows creation of quickly expanded user interfaces and easy assigning of functionalities implemented in language C++, while keeping an attractive interface. The program enables a hypsometric map to be downloaded, viewed as a contour map and as a finally generated 3D-model. In addition, the application allows a texture model and fog effect to be imposed on the generated surface features, thus making the scene more realistic.

Creating flexible web applications on example of content management system

Nowak, Kamil
Article
2008
In the paper a way of creating flexible web applications has been shown. It describes division of application into layers to ensure control separation of the user (controller), generated content (view) and internal decision process (model). It also presents a technique which allows independence of data source. It shows how to design an application that can be easily extended in a safe way.

Dynamic research on gear-and-lever motion drives

Neymak, Vitaliy
Article
2008
Gear-and-lever is the most perspective for creating modern machines and devices. But the dynamic effect of these mechanisms on the frequency of rotation (over 1500 rotations per minute) in a modern warp knitting machine has not been investigated yet. The dynamic model must be understood as an ideal representation of the system in question for further usage in theoretical researches and engineering calculations. Any dynamic model appears to be limited and suitable under some conditions and with some questions taken into account.

Mobile wind turbine

NÆss, Øystein Djuvik N, Ytredal, Hilde
Article
2008
The paper describes the function of a wind turbine, and different aspects you have to take into consideration during construction. A computing programme has been used to design and optimise the wind turbine, so it can be as light as possible.