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Application of the digital image correlation in the measurement of residual stresses by the hole-drilling method
Plucnar, Tomáš ; Horák, Richard (referee) ; Halabuk, Dávid (advisor)
The thesis focuses on the measurement of residual stresses using digital image correlation (DIC). The work describes residual stresses and also derives an analytical description of the deformation around a drilled hole, which is essential for evaluating the experiment. The largest part of the thesis is dedicated to the measurement and evaluation of residual stresses. Within the framework of the thesis, measurements of residual stresses were conducted for samples with pre-drilled holes and also for solid samples into which holes were drilled. These measurements were then used to evaluate the effects of various DIC software settings on the assessed residual stress. Measurements on samples with pre-drilled holes were used to determine the impact of the random pattern density and the influence of the camera on the evaluated residual stress.
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Determination of stress resultants in closed frames
Horák, Richard ; Horníková, Jana (referee) ; Vaverka, Jiří (advisor)
The bachelor's thesis deals with the determination of the internal stress resultants (ISR) of planar beams with a closed centerline. The first part of the thesis presents a theoretical basis, which is then applied in the second part to solve three tasks. In the first task, the theory of symmetrical and antimetrical course of ISR is applied to reduce the degree of static indeterminacy of a symmetrical planar beam loaded by a symmetrical and antimetrical force system. In the second task the method of superposition is used to replace the general external load of the beam by symmetrical and antimetrical external loads. The task is further solved in the same way as in the case of the first task. The third task is solved by a general procedure with several options of released structures. Furthermore, the assumption enabling the solution of the stress energy due to the bending moment only is verified. At the end of the third task, the analytically determined values are compared with the values determined by the numerical method using the software ANSYS.
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Increase the Rated Voltage of the Vehicle's Circuit - Study
Horák, Richard ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
The point of this work is evaluate the parameters of automotive electric system and according to these properties choose suitable norm of higher voltage, propose conception of system and with analyst calculation suggest basic granary parameters of higher voltage. This calculation is enclosed. In the work is mentioned a historical development of required escalation in system and therewith connected changes of specified levels of system tension. As an exemplification of escalation calculus hereof electrical equipment, installed onto motor powered vehicle, are mentioned in attachment schema's of four vehicles Škoda Auto a.s.
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Determination of residual stresses from strain field around drilled hole
Horák, Richard ; Návrat, Tomáš (referee) ; Halabuk, Dávid (advisor)
The master’s thesis focuses on determining homogeneous residual stresses using the hole-drilling method. The optical method of digital image correlation (DIC) is used for measuring released strains. In order to evaluate residual stresses using the entire strain field, it is necessary to know the functional dependencies of calibration constants on this field. Therefore, a significant part of the master’s thesis includes finding these dependencies in relation to the dimensions of the drilled hole and coordinates of the measured points. Another part of the thesis deals with the evaluation of homogeneous residual stresses based on provided experimental data obtained from the measurement of uniaxially loaded steel flat bar with a through-hole. At the end of the thesis, a sensitivity analysis is performed, which examines the influence of input variables in the calculation algorithm in relation to computed residual stresses.
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Determination of stress resultants in closed frames
Horák, Richard ; Horníková, Jana (referee) ; Vaverka, Jiří (advisor)
The bachelor's thesis deals with the determination of the internal stress resultants (ISR) of planar beams with a closed centerline. The first part of the thesis presents a theoretical basis, which is then applied in the second part to solve three tasks. In the first task, the theory of symmetrical and antimetrical course of ISR is applied to reduce the degree of static indeterminacy of a symmetrical planar beam loaded by a symmetrical and antimetrical force system. In the second task the method of superposition is used to replace the general external load of the beam by symmetrical and antimetrical external loads. The task is further solved in the same way as in the case of the first task. The third task is solved by a general procedure with several options of released structures. Furthermore, the assumption enabling the solution of the stress energy due to the bending moment only is verified. At the end of the third task, the analytically determined values are compared with the values determined by the numerical method using the software ANSYS.
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Increase the Rated Voltage of the Vehicle's Circuit - Study
Horák, Richard ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
The point of this work is evaluate the parameters of automotive electric system and according to these properties choose suitable norm of higher voltage, propose conception of system and with analyst calculation suggest basic granary parameters of higher voltage. This calculation is enclosed. In the work is mentioned a historical development of required escalation in system and therewith connected changes of specified levels of system tension. As an exemplification of escalation calculus hereof electrical equipment, installed onto motor powered vehicle, are mentioned in attachment schema's of four vehicles Škoda Auto a.s.
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