|
|
Analytical workplace for gas valves
Skočík, Pavel ; Havránek, Zdeněk (referee) ; Klusáček, Stanislav (advisor)
This work deals with the measurement of parameters of different types of gas control valves, of a assembling measuring workplace and development of a program for a complex control system consisting of the Siemens acquisition boards and software resources LabVIEW. The program stores the values of inlet and outlet pressure, flow, time or modulation current into a text file. The timing and number of samples can be changed. Outlet pressure versus time or modulation current is displayed on the monitor chart.
|
|
|
Development And Verification Of A New Method For Measuring The Stiffness And Damping Properties Of Joints In Parallel Kinematic Structures
Kolouch, Martin ; Tomáš, Jiří (referee) ; Knoflíček, Radek (advisor)
In this dissertation is presented the development of a new measurement method for the stiffness and damping characteristics of a joint in a parallel kinematic machine tool. The main contribution of this method is specially for applications, that demand accurate information about stiffness and damping parameters from assembled parts of machines tool. Methods for compensation of deformations in machines tool, that are carried out by control, belong to these applications. Another contribution of this work is the technical implementation of the proposed principle of the new method. At this point the focus of the work was devoted to signal processing, that differs in a certain degree from other types of signal processing methods, that are used in other dynamic measurements, e.g. modal analysis. One of the main requirements was the possibility to consider the nonlinear behavior of the measured structure. In another chapter the modified signal processing method was used for measuring a joint in a test rig. The results were compared with results from other measurement methods. On account of this comparison the statement was made that the new method can be used for measuring the stiffness and damping parameters of machine parts. Finally the new method was applied to measure the properties of a joint, which was built in a machine tool. Moreover, the problems, that appeared during the measurement, were also described.
|
|
|
Losses Analysis in Electric Machines under Special Conditions
Bulín, Tomáš ; Rafajdus, Pavol (referee) ; Skala, Bohumil (referee) ; Ondrůšek, Čestmír (advisor)
This thesis deals with the analysis of magnetic losses in electrical machines and the possibilities of their measurement. Magnetically soft and hard materials are very prone to changing magnetic properties. They can be changed simply by changing the temperature of the material or different stresses induced in the material, resulting in different results. These changes are important to keep in mind when an electric machine is being designed. The original parameters of the affected materials can be restored by annealing or grinding. These methods release the induced stresses within the material. Due to these effects, it is also important to know how to measure magnetic parameters. Each way has its own specifics and has a certain error of the measurement. When the machines for higher efficiency, rpm or higher temperatures are designed, it is advisable to know how their magnetic properties changed. This thesis deals with the properties of different materials, their measurements and finally simulation of the chosen electric machine with the application of the measured results.
|
|
|
Verification of nonlinear material models of concrete
Král, Petr ; Němec, Ivan (referee) ; Hradil, Petr (advisor)
Diploma thesis is focused on the description of the parameters of nonlinear material models of concrete, which are implemented in a computational system LS-DYNA, interacting with performance of nonlinear test calculations in system LS-DYNA on selected problems, which are formed mainly by simulations of tests of mechanical and physical properties of concrete in uniaxial compressive and tensile on cylinders with applying different boundary conditions and by simulation of bending slab, with subsequent comparison of some results of test calculations with results of the experiment. The thesis includes creation of appropriate geometric models of selected problems, meshing of these geometric models, description of parameters and application of nonlinear material models of concrete on selected problems, application of loads and boundary conditions on selected problems and performance of nonlinear calculations in a computational system LS-DYNA. Evaluation of results is made on the basis of stress-strain diagrams and load-displacement diagrams based on nonlinear calculations taking into account strain rate effects and on the basis of hysteresis curves based on nonlinear calculations in case of application of cyclic loading on selected problems. Verification of nonlinear material models of concrete is made on the basis of comparison of some results of test calculations with results obtained from the experiment.
|
|
|
Fluxmeter with graphical display of B-H curve
Ježek, Jaroslav ; Mačák, Jaromír (referee) ; Hanák, Pavel (advisor)
This work deals with simple fluxmeter which is able, together with other device, to show hysteresis loop. Hysteresis loop is a graphic expression of dependence of magnetic induction on intensity of magnetic field. Oscilloscope is used to display the hysteresis loop. This device is fully sufficient for the display. The measured objects are solenoids from various kinds of materials with the same shape. The main aim of this work is the design, realization and description of the fluxmeter. The fluxmeter consists of several partial blocks. The first one, on which this work is focused, is signal generator which is able to generace different kinds of signal. The generated signal comes on primary winding of solenoid where a magnetic field on a given intensity rises. An amplifier is used to obtain the sufficient intensity. Next thing this work is focused on is the design of the integrator which is necessary for the correct function of the fluxmeter. As suggested, there is shown the block diagram of linking of individual parts. There are described the measured results at the end of this work.
|
|
|
Measurement and recording of the initial magnetization curve and hysteresis curve of ferromagnetic materials
Tran, Quoc Bao ; Vaněk, Jiří (referee) ; Klvač, Ondřej (advisor)
This thesis deals with the measurement of primary magnetization curves and hysteresis loop. The thesis is divided into two parts, the theoretical part and the practical part. The theoretical part describes the creation of magnetic field in materials, excitation of magnetic field by electric current or excitation of electric current by changing magnetic field. The practical part is focused on designing, construction and testing of amplifier and the measurement and displaying of hysteresis loop. In the end of the thesis is summarized what results were achieved.
|
|
|
Measurement of the magnetic properties of materials using LabVIEW
Šolc, Martin ; Bulín, Tomáš (referee) ; Huzlík, Rostislav (advisor)
In this thesis LabVIEW program and its development environment is described. After that the most used current transducers, their working principles and their properties are analyzed. Next part is dedicated to curves of magnetic hysteresis of ferromagnetic materials. Practical part of bachelor´s thesis is dedicated to measuring BH curves of torroidal core transformer. The measuring was made possible by LabVIEW program, using digital integration in LabVIEW, analog integration with RC cell, voltage converter and current transducer ITN 12-P Ultrastab. In the last part of the bachelor´s thesis I evaluate the measurements.
|
|
|
Measurement and recording of the initial magnetization curve and hysteresis curve of ferromagnetic materials
Tran, Quoc Bao ; Vaněk, Jiří (referee) ; Klvač, Ondřej (advisor)
This thesis deals with the measurement of primary magnetization curves and hysteresis loop. The thesis is divided into two parts, the theoretical part and the practical part. The theoretical part describes the creation of magnetic field in materials, excitation of magnetic field by electric current or excitation of electric current by changing magnetic field. The practical part is focused on designing, construction and testing of amplifier and the measurement and displaying of hysteresis loop. In the end of the thesis is summarized what results were achieved.
|
|
|
Losses Analysis in Electric Machines under Special Conditions
Bulín, Tomáš ; Rafajdus, Pavol (referee) ; Skala, Bohumil (referee) ; Ondrůšek, Čestmír (advisor)
This thesis deals with the analysis of magnetic losses in electrical machines and the possibilities of their measurement. Magnetically soft and hard materials are very prone to changing magnetic properties. They can be changed simply by changing the temperature of the material or different stresses induced in the material, resulting in different results. These changes are important to keep in mind when an electric machine is being designed. The original parameters of the affected materials can be restored by annealing or grinding. These methods release the induced stresses within the material. Due to these effects, it is also important to know how to measure magnetic parameters. Each way has its own specifics and has a certain error of the measurement. When the machines for higher efficiency, rpm or higher temperatures are designed, it is advisable to know how their magnetic properties changed. This thesis deals with the properties of different materials, their measurements and finally simulation of the chosen electric machine with the application of the measured results.
|
|
|
Measurement of the magnetic properties of materials using LabVIEW
Šolc, Martin ; Bulín, Tomáš (referee) ; Huzlík, Rostislav (advisor)
In this thesis LabVIEW program and its development environment is described. After that the most used current transducers, their working principles and their properties are analyzed. Next part is dedicated to curves of magnetic hysteresis of ferromagnetic materials. Practical part of bachelor´s thesis is dedicated to measuring BH curves of torroidal core transformer. The measuring was made possible by LabVIEW program, using digital integration in LabVIEW, analog integration with RC cell, voltage converter and current transducer ITN 12-P Ultrastab. In the last part of the bachelor´s thesis I evaluate the measurements.
|
guest ::
