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Increasing of Energy Efficiency of Spindles with Fluid Bearings

), Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use, Sustainability in Manufacturing. Energy Efficiency in Machine Tools , 263-267. 5. EC - 7th Framework Programme. Challenge 6: ICT for Mobility, Environmental Sustainability and Energy Efficiency. Deliverable D3.3: “Design for energy efficiency” (2013), Estomad Project . 6. Fedorynenko D., Boyko S., Sapon S. (2015), The search of the spatial functions of pressure in adjustable hydrostatic radial bearing, Acta Mechanica et Automatica , 9(1), 23-26. 7

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Shape Identification in Nonlinear Boundary Problems Solved bby Pies Method

Abstract

The paper presents the strategy for identifying the shape of defects in the domain defined in the boundary value problem modelled by the nonlinear differential equation. To solve the nonlinear problem in the iterative process the PIES method and its advantages were used: the efficient way of the boundary and the domain modelling and global integration. The identification was performed using the genetic algorithm, where in connection with the efficiency of PIES we identify the small number of data required to the defect’s definition. The strategy has been tested for different shapes of defects.

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Transient Analysis of a Railgun with Permanent Magnets Support

Abstract

The calculation and measurement results of transients for an electrodynamic accelerator with permanent magnet support have been presented in this paper. The calculations have been made using the magnetostatic model in the Maxwell software, as well as using a Matlab/Simulink transient model. The waves of mechanical parameters (projectile velocity and acceleration, force) and electric ones (excitation current and capacitor voltage) have been analyzed for different supply conditions (voltage value, capacitance). The efficiency and projectile energy have been studied as well. The mathematical models have been verified experimentally using the original laboratory stand. A good conformity between calculation and measurement results has been obtained.

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Surface Layer Properties of Low-Alloy High-Speed Steel after Grinding

Abstract

Investigations of the surface layer characteristics of selected kinds of low-alloy high-speed steel after grinding were carried out. They were carried out on the flat-surface grinder with a 95A24K grinding wheel without cooling. The influence of grinding parameters was defined especially for: the quantity of secondary austenite, surface roughness, microhardness and grinding efficiency with a large range of grinding parameters: grinding depth 0.005–0.035 mm, lengthwise feed 2–6 m/min, without a cross-feed on the whole width of the sample. It was found that improvement of grinding properties of low-alloy high-speed steels is possible by efficient selection of their chemical composition. The value of the grinding efficiency is conditioned by grinding forces, whose value has an impact on the grinding temperature. To ensure high quality of the tool surface layer (i.e. a smaller amount of secondary austenite, lack of wheel burn and micro-cracks) in the case of sharpening of tools made of low-alloy high-speed steel, the grinding temperature should be as low as possible.

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Diagnosis of Discrete-Time Singularly Perturbed Systems Based on Slow Subsystem

Abstract

This paper deals with the diagnosis of discrete-time singularly perturbed systems presenting two time scales property. Parity space method is considered to generate the fault detection residual. The focus is in two directions. First, we discuss the residual illconditioning caused by the singular perturbation parameter. Then, the use of the slow subsystem is considered to make the fault diagnosis easier. It is shown that the designed diagnostic algorithm based on reduced order model is close to the one synthesized using the full order system. The developed approach aims at reducing the computational load and the ill-conditioning for stiff residual generation problem. Two examples of application are used to demonstrate the efficiency of the proposed method.

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AIR FLOW ANALYSIS FOR ELECTRICAL MOTOR'S COOLING SYSTEM WITH AUTODESK SIMULATION CFD 2013 PROGRAM

Abstract

In the article the analysis of airflow through electrical motor was conducted and optimal design solution was chosen in order to increase cooling efficiency. Numerical simulations allow to determine the areas of temperature occurrence which may have destructive influence on electrical motor parts and on its safe operation. The numerical calculations of airflow was carried out for two different types of fans as well as for two different housings. An analysis of the construction was carried out by CFD method using Autodesk Simulation CFD 2013. Community results of the analysis, we can conclude that the better solution for machines with fixed direction of rotation is to use instead of the radial the axial fan. For axial fan the motor temperature in the same condition was lower by about 5°C.

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Modelling the Meshing of Cycloidal Gears

REFERENCES 1. Bednarczyk S. (2013), Cycloidal gear development focused on the transfer of efficiency of the machines, In: Idzikowski A.: Efficiency of working machines and equipment in the industry , Press WZ PCz, Czestochowa, 117-225. 2. Bednarczyk S. (2014), Determination of the gear geometry of the of the cyclo gear , Silesia University of Technology Scientific Notebooks, Gliwice, 29-39. 3. Blagojevic M., Kocic M., Marjanovic N., Stojanovic B., Dordevic Z., Ivanovic L., Marjanovic V. (2012), Influence of the friction on the cycloidal

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Intellectualization of Emergency Control of Power Systems on the Basis of Incorporated Ontologies of Knowledge-Bases

Abstract

The research deals with improvement of methods and systems of controlling integrated power systems (IPSs) on the basis of intellectualization of decision-making support. Complex analysis of large-scale accidents at power facilities is performed, and their causes and damages are determined. There is substantiated topicality of building condition knowledge-bases as the foundation for developing decision-support systems in power engineering. The top priorities of the research include developing methods of building a knowledge base based on intensity models of control actions influencing the parameters of power system conditions and introducing the smart system into information contours of the automated dispatch control system (ADCS), as well as assessing practical results of the research. To achieve these goals, the authors apply methods of experiment planning, artificial intelligence, knowledge presentation, mathematical simulation, and mathematical statistics as well as methods of power systems studying. The basic research results include regression models of a power system sensitivity to control actions, methods of building a knowledge base based on the models of sensitivity matrices, a structure of the smart decision-support system, a scheme of introducing the decision-support system into the operating ADCS environment. The problem of building a knowledge base of the dispatch decision-support system on the basis of empirical data resulted from calculating experiments on the system diagram has been solved. The research specifies practical efficiency of the suggested approaches and developed models.

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Modeling and Operational Analysis of an Automotive Shock Absorber with a Tuned Mass Damper

Abstract

Recently, the topic of energy dissipation efficiency of vehicle suspension dampers has become a research and engineering problem due to structural requirements of vehicle manufacturers and the introduction of electric/hybrid cars. By principle, any disturbances in the damping force generation process translate into pressure fluctuations to be then transferred to the body of the vehicle. The effect known as rattling within the damper engineering community is perceived as detrimental to ride comfort. To improve the performance of a vehicle damper several methods can be devised and used. One approach is to optimize the settings of the valves in the damper. The approach, however, often influences the force output of the damper. Another technique involves the application of add-on systems. One such system is the tuned mass damper concept originally developed by Frahm for structural engineering applications. In the paper the author proposes a damper concept equipped with an external/internal tuned mass damper component for improving the dynamic characteristics of vehicle dampers. The author presents modeling details followed by simulations of the damper with the tuned mass damper concept subjected to oscillatory inputs, and a critical analysis of the presented results.

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DYNAMIC TESTING OF COPPER MATERIAL – NUMERICAL APPROACH

Abstract

Split Hopkinson pressure bar (SHPB) is one of the most important and recognisable apparatus used for characterizing the dynamic behaviour of various materials. Incident pulse generated one the incident bar usually have a rectangular shape, which is proper for some materials but for others is not. Therefore, several methods of shaping the incident pulse are used for obtaining constant strain rate conditions during tests. Very often pulse shapers made of copper or similar material are implemented due to its softness properties. In this paper such material was investigated using the FE model of SHPB. Its mechanical behaviour was characterised with and without copper disc between the striker and incident bar. Numerical simulations were carried out using explicit LS-DYNA code. Two different methods were used for modelling the copper sample: typical finite Lagrangian elements and meshless Smoothed Particle Hydrodynamics (SPH) method. As a result of two techniques used axial stress-strain characteristics were compared for three different striker’s velocity with an influence of the copper pulse shaper taking into account. Finally, FE and SPH method was compared with taking into consideration: the efficiency, computer memory and power requirements, complexity of methods and time of simulation

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