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Analysis of the dynamic effects in the turnout
Vukušič, Ivan ; Zvěřina, Pavel (referee) ; Hřebačka,, Milan (referee) ; Smutný, Jaroslav (advisor)
The vibration of the railway superstructure is mainly influenced by its quality, by the operational technical conditions, climatic phenomena and above all by the dynamic load by the pair of wheels of the rail vehicles and also by the quality of railway subgrade. Simultaneously, the dynamic parameters also depend on the speed of rail vehicles, on the arrangement of axles, their spring mounting and on the spring mounting of the body casing or on the weight acting on the axle, and last but not least, also on the quality of the running surface of the wheel tyre. The dynamic effects of sets of wagons are transferred through the rails to the rail pads below the base of the rails, then to the sleepers or bearers and fastening system, then to the ballast bed and also to the superstructure construction. This fact applies especially for turnout structures. In turnout rigidity is changed and also there is a place where the wheel passes over a gap (in case of fixed crossings). In particular of above mentioned reasons, turnout is a place where high dynamic effects occurre and that is why often defects occurre. Dissertation thesis will be focused on measurement and analysis of the dynamic effects on turnout. The point of the thesis will be updating recent system (observing of the geometrical parameters and wear of the rails in turnouts) for dynamic effect observe. Methodology of the measurement and convenient mathematical apparatus for analysing dynamic effect will be proposed.
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Measurement and Evaluation Methods of Powertrain Vibrations
Vítek, Michal ; Janoušek, Michal (referee) ; Prokop, Aleš (advisor)
This bachelor´s thesis deals with the methods of measurement and evaluation of powertrain vibrations. Introduction of this work is defining the basic parameters of vibration. It also shows the experimental modal analysis, vibration excitation methods and measuring responses to a given excitation. The last part is operational modal analysis and its comparison with experimental modal analysis.
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Vibration sensor
Matěj, Jan ; Pristach, Marián (referee) ; Bohrn, Marek (advisor)
This Bachelor’s thesis deals with a system for reading the radar antenna gearbox vibrations. Firstly it names different types of sensors and defines their suitability for this usage. Secondly it describes the system for data transmission from transducer to computer and also explains meaning of the measured results.
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Processing of digital signals from interferometer
Trličík, Jakub ; Čejka, Miloslav (referee) ; Havránek, Zdeněk (advisor)
Abstract This bachelor thesis deals with the S/PDIF digital signal processing from interferometer Polytec OFV-5000, by measurement application created in LabVIEW. This paper describes the theory of laser vibration measurement and encoding S/PDIF digital signal. Text also introduces a Polytec system for vibration measurement and system for data acquisition by National Instruments. The following is a description of the created measurement application, divided into three parts: decoding an S/PDIF, acquisition and display of digital data and acquisition and display of analog data to compare with digital output. In the last part of the thesis are presented the results of comparing analog and digital output, and an evaluation of the achieved results.
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Fiber-Optic Sensors
Dejdar, Petr ; Róka,, Rastislav (referee) ; Kyselák, Martin (referee) ; Münster, Petr (advisor)
Optical networks are continuously expanding and this creating space for the use of optical fibers for non-data transmissions. One of them is the use for sensing purposes, where optical fibers can be used to measure temperature, pressure, vibration, etc. In standard conditions or in conditions where the placement of conventional sensors is not suitable (increased humidity, radiation, lack of space, etc.).This paper is devoted to the comparison of technologies comparing sensing systems and describes their principle and their possible applications. Subsequently, the different systems are built and tested. Possible improvements are then proposed based on the measurements, where for the reflectometric system the advantages of using edge detection algorithms are quantified. For the polarization detectors, improvements are made using machine learning classification algorithms with classification success rates above 97 %. Detailed measurements of the sensitivity of optical fibers to acoustic vibrations in three different environments, with different path configurations, cables, vibration-damping materials, etc. are also described. These measurements proved the possibility of intercepting optical fibers using interferometric, reflectometric, and polarization systems, where the polarization system is proven to be the least sensitive and records only lower frequencies. Based on these measurements, a system for securing the physical layer of optical networks is then proposed, which is able to accurately distinguish the quiescent and cable manipulation states from the datasets we created.
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Methods of technical diagnostics - vibrodiagnostics
Soldán, Josef ; Hammer, Miloš (referee) ; Hájková, Alena (advisor)
The bachelor's thesis deals with technical diagnostics, especially vibrodiagnostics. The work first describes technical diagnostics in general, namely its means and methods, including vibrodiagnostics. The mentioned method is the focus of the presented bachelor's thesis, therefore its description forms the majority of the theoretical part. As part of this work, the vibrations of the electric motor were measured, which were subsequently evaluated according to the standard.
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Optical fiber sensors for measurement strain and vibration
Mikel, Břetislav ; Helán, R. ; Buchta, Zdeněk ; Holík, M. ; Jelínek, Michal ; Číp, Ondřej
We present optical fiber sensors to measurement strain and vibration. The sensors are based on fiber Bragg gratings (FBG). We prepared construction of strain sensors with respect to its implementation on the outer surface of concrete structures and with compensation of potential temperature drifts. These sensors are projected with look forward to maximal elongation and strength which can be applied to the sensor. Each sensor contains two optical fibers with FBGs. One FBG is glued into the sensor in points of fixation which are in the line with mounting holes. This FBG is prestressed to half of measurement range, than the stretching and pressing can be measured simultaneously by one FBG. The second FBG is placed inside the sensor without fixation to measure temperature drifts. The sensor can be used to structure health monitoring.
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Analysis of the dynamic effects in the turnout
Vukušič, Ivan ; Zvěřina, Pavel (referee) ; Hřebačka,, Milan (referee) ; Smutný, Jaroslav (advisor)
The vibration of the railway superstructure is mainly influenced by its quality, by the operational technical conditions, climatic phenomena and above all by the dynamic load by the pair of wheels of the rail vehicles and also by the quality of railway subgrade. Simultaneously, the dynamic parameters also depend on the speed of rail vehicles, on the arrangement of axles, their spring mounting and on the spring mounting of the body casing or on the weight acting on the axle, and last but not least, also on the quality of the running surface of the wheel tyre. The dynamic effects of sets of wagons are transferred through the rails to the rail pads below the base of the rails, then to the sleepers or bearers and fastening system, then to the ballast bed and also to the superstructure construction. This fact applies especially for turnout structures. In turnout rigidity is changed and also there is a place where the wheel passes over a gap (in case of fixed crossings). In particular of above mentioned reasons, turnout is a place where high dynamic effects occurre and that is why often defects occurre. Dissertation thesis will be focused on measurement and analysis of the dynamic effects on turnout. The point of the thesis will be updating recent system (observing of the geometrical parameters and wear of the rails in turnouts) for dynamic effect observe. Methodology of the measurement and convenient mathematical apparatus for analysing dynamic effect will be proposed.
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Vibration sensor
Matěj, Jan ; Pristach, Marián (referee) ; Bohrn, Marek (advisor)
This Bachelor’s thesis deals with a system for reading the radar antenna gearbox vibrations. Firstly it names different types of sensors and defines their suitability for this usage. Secondly it describes the system for data transmission from transducer to computer and also explains meaning of the measured results.
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