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Development of a New Generation of Devices with Advanced Diagnostics for Determining Contact Degradation
Dvořáček, Jiří ; Hájek, Karel (referee) ; Náhlík, Luboš (referee) ; Pazdera, Luboš (referee) ; Mazal, Pavel (advisor)
The thesis proposes a methodology for damage identification of thrust bearings using acoustic emission method. The work is the way of the hydraulic loading of specimens and thrust bearings with programmable settings severity and duration of load cycles during contact fatigue tests at stations Axmat. They are designed structural adjustment elements (waveguides) to capture the acoustic emission signal selected apparatus, including the modification of software to capture the data. At the described experiments is verified functionality of the circular test specimens and axial bearings . Part of this work is to propose a new methodology for identifying early stages of contact fatigue using a combination of diagnostic methods.
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Reconstruction of AXMAT Testing Station
Gergel, Matej ; Dobeš, Petr (referee) ; Dvořáček, Jiří (advisor)
The master´s thesis deals with reconstruction of RCF test rig AXMAT. Main goal is design new hydraulic load system and his realization. The first part of thesis describes similar experimental machines and their pros and cons. This analysis is base for complete reconstruciton of AXMAT. New hydraulic load system allows dynamic programmable load cycles. Control system with close loop and feedback was created in software Matlab – Simulink. Main frame was reconstructed too. Control and action parts were asseble to station. Output of thesis is function sample.
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Correlation of AE Signal Changes to Rolling Contact Damage Propagation
Nohál, Libor ; Čermák, Jan (referee) ; Hájek, Karel (referee) ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This PhD thesis deals with the experimental study of more precise rolling contact fatigue damage detection using acoustic emission method. A series of experiments was carried out on two representatives bearing steels and the analysis of sensitivity for the presence of contact damage was performed on selected parameters of acoustic emission. The extent of damage was classified into four classes and signal parameters the most characterizing the development of damage were correlated with the extent of damage. It was also verified the influence of lubricants on acoustic emission signals. The results have an impact on the implementation of more precise rolling contact fatigue tests and evaluation of parameters of acoustic emission signal. On the basis of experiments was established methodology for more precise RCF testing method using acoustic emission on test-rig AXMAT II.
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Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
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Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
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|
Correlation of AE Signal Changes to Rolling Contact Damage Propagation
Nohál, Libor ; Čermák, Jan (referee) ; Hájek, Karel (referee) ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This PhD thesis deals with the experimental study of more precise rolling contact fatigue damage detection using acoustic emission method. A series of experiments was carried out on two representatives bearing steels and the analysis of sensitivity for the presence of contact damage was performed on selected parameters of acoustic emission. The extent of damage was classified into four classes and signal parameters the most characterizing the development of damage were correlated with the extent of damage. It was also verified the influence of lubricants on acoustic emission signals. The results have an impact on the implementation of more precise rolling contact fatigue tests and evaluation of parameters of acoustic emission signal. On the basis of experiments was established methodology for more precise RCF testing method using acoustic emission on test-rig AXMAT II.
|
|
|
Development of a New Generation of Devices with Advanced Diagnostics for Determining Contact Degradation
Dvořáček, Jiří ; Hájek, Karel (referee) ; Náhlík, Luboš (referee) ; Pazdera, Luboš (referee) ; Mazal, Pavel (advisor)
The thesis proposes a methodology for damage identification of thrust bearings using acoustic emission method. The work is the way of the hydraulic loading of specimens and thrust bearings with programmable settings severity and duration of load cycles during contact fatigue tests at stations Axmat. They are designed structural adjustment elements (waveguides) to capture the acoustic emission signal selected apparatus, including the modification of software to capture the data. At the described experiments is verified functionality of the circular test specimens and axial bearings . Part of this work is to propose a new methodology for identifying early stages of contact fatigue using a combination of diagnostic methods.
|
|
|
Reconstruction of AXMAT Testing Station
Gergel, Matej ; Dobeš, Petr (referee) ; Dvořáček, Jiří (advisor)
The master´s thesis deals with reconstruction of RCF test rig AXMAT. Main goal is design new hydraulic load system and his realization. The first part of thesis describes similar experimental machines and their pros and cons. This analysis is base for complete reconstruciton of AXMAT. New hydraulic load system allows dynamic programmable load cycles. Control system with close loop and feedback was created in software Matlab – Simulink. Main frame was reconstructed too. Control and action parts were asseble to station. Output of thesis is function sample.
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