|
|
Fatigue Life Evaluation of Composites Structures
Mihalides, Dušan ; Kopřiva, Tomáš (referee) ; Juračka, Jaroslav (referee) ; Klement, Josef (advisor)
The doctoral thesis deals with fatigue life evaluation of composites structures. The thesis pro-vides complex review of problematic and it is based on recent situation assessment. The main ob-jective of the thesis is to design the methodology of fatigue life evaluation of composites struc-tures. The designed methodology is applied to fatigue life evaluation of sailplane wing and propel-ler blades. One part of the thesis deals with laboratory fatigue tests of composite specimens which are intended for comparison of the effect of manufacturing technology and environment condition.
|
|
|
Numerical support for description of behavior of cement based composite during fatigue test
Holušová, Táňa ; Padevět,, Pavel (referee) ; PhD, Ladislav Řoutil, (referee) ; Seitl, Stanislav (advisor)
The presented dissertation thesis is focused on analysis of alternative test method for determination of mechanical parameters of cement based composites. A disk shaped specimen with diameter 150 mm, thickness 60 mm was analysed and its modification for use on compact tension test (CT). Such a test is hereinafter referred to as modified compact tension (shortly MCT or MDCT)). This test configuration was chosen for testing the static and fatigue properties of cement based composites precisely because of its traditional use for fatigue testing of metallic materials. Specimens with a different cross-sections can also be used for MCT, but the work is exclusively focused on circular specimen, for example because it could be easily cut from drill core taken directly from the existing structure, on which the properties are more relevant to the age of the used concrete of the controlled structure. The modified compact tension test was firstly calibrated by numerical simulations involved the tuning of the shape of the numerical model and used material models of concrete and steel. Then the laboratory testing of modified compact tension on several levels were performed. The adequacy of the numerical model was verified against the pilot laboratory testing of the MCT test. Furthermore, the comparison of the modified compact tension test and its suitability for determining of fracture mechanical parameters of cement based composites with the three point bending test, which is the standardized test configuration for these purposes was performed. Another laboratory testing was focused of determining of fracture mechanical parameters of concrete mixture classified in strength class C30/37 and the pilot study of fatigue parameters of the same strength class of the concrete mix. The work was also presented numerical simulations of the push-out test, focused on the connection of concrete and steel with epoxy adhesive.
|
|
|
Fatigue Evaluation of Aircraft Structure According to FAR Part 23 Airworthiness Standards
Čermák, Jakub ; Koštial, Rostislav (referee) ; Augustin, Petr (advisor)
This bachelor thesis deals with acceptable means of showing compliance with the FAR 23 regulation based on safe-life experimental and analytical evaluation. In the introduction the author focuses on the historical development of the regulation and follows with summarization of current requirements. The subsequent pages describes in detail the certification based on full-scale testing, component testing and structural analysis using the cumulative rule. Appendix includes examples of load spectra approved by the FAA.
|
|
|
Numerical support for description of behavior of cement based composite during fatigue test
Holušová, Táňa ; Padevět,, Pavel (referee) ; PhD, Ladislav Řoutil, (referee) ; Seitl, Stanislav (advisor)
The presented dissertation thesis is focused on analysis of alternative test method for determination of mechanical parameters of cement based composites. A disk shaped specimen with diameter 150 mm, thickness 60 mm was analysed and its modification for use on compact tension test (CT). Such a test is hereinafter referred to as modified compact tension (shortly MCT or MDCT)). This test configuration was chosen for testing the static and fatigue properties of cement based composites precisely because of its traditional use for fatigue testing of metallic materials. Specimens with a different cross-sections can also be used for MCT, but the work is exclusively focused on circular specimen, for example because it could be easily cut from drill core taken directly from the existing structure, on which the properties are more relevant to the age of the used concrete of the controlled structure. The modified compact tension test was firstly calibrated by numerical simulations involved the tuning of the shape of the numerical model and used material models of concrete and steel. Then the laboratory testing of modified compact tension on several levels were performed. The adequacy of the numerical model was verified against the pilot laboratory testing of the MCT test. Furthermore, the comparison of the modified compact tension test and its suitability for determining of fracture mechanical parameters of cement based composites with the three point bending test, which is the standardized test configuration for these purposes was performed. Another laboratory testing was focused of determining of fracture mechanical parameters of concrete mixture classified in strength class C30/37 and the pilot study of fatigue parameters of the same strength class of the concrete mix. The work was also presented numerical simulations of the push-out test, focused on the connection of concrete and steel with epoxy adhesive.
|
|
|
Fatigue Life Evaluation of Composites Structures
Mihalides, Dušan ; Kopřiva, Tomáš (referee) ; Juračka, Jaroslav (referee) ; Klement, Josef (advisor)
The doctoral thesis deals with fatigue life evaluation of composites structures. The thesis pro-vides complex review of problematic and it is based on recent situation assessment. The main ob-jective of the thesis is to design the methodology of fatigue life evaluation of composites struc-tures. The designed methodology is applied to fatigue life evaluation of sailplane wing and propel-ler blades. One part of the thesis deals with laboratory fatigue tests of composite specimens which are intended for comparison of the effect of manufacturing technology and environment condition.
|
|
|
Fatigue Evaluation of Aircraft Structure According to FAR Part 23 Airworthiness Standards
Čermák, Jakub ; Koštial, Rostislav (referee) ; Augustin, Petr (advisor)
This bachelor thesis deals with acceptable means of showing compliance with the FAR 23 regulation based on safe-life experimental and analytical evaluation. In the introduction the author focuses on the historical development of the regulation and follows with summarization of current requirements. The subsequent pages describes in detail the certification based on full-scale testing, component testing and structural analysis using the cumulative rule. Appendix includes examples of load spectra approved by the FAA.
|
|
| |
|
|
Statistical processing of fatigue experiments
Balda, Miroslav
The contribution deals with testing of material on fatigue and processing of measured fatigue data. The subject has connections both with material science and statistics. Since both domains are very wide, only parts important for the subject were treated from the engineering print of view. Besides standard fatigue test procedures, new approaches used for identification of material parametrs were also be discussed.
|
|
| |
|
|
Generating a special loading processes
Balda, Miroslav
New computing methods for assessment of fatigue lives of machine parts exposed to combined stress should be tested. With a view to it, fatigue experiments are pursued with predefined periodic processes compounded of deterministic time functions of normal and shear stresses. A straight application of simple functions leads to improper results due to dynamic properties of the testing machine. The contribution describes a way of generating loading processes of much better properties.
|
guest ::
