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Creating geometrical models of selected implants of hip joint
Kohoutek, Jan ; Vosynek, Petr (referee) ; Návrat, Tomáš (advisor)
According to the specification, the concept of the thesis is a research study, which is supposed to present global overview of the hip joint arthroplasty. It involves a short summary of basic methods used in biomechanical measurements of bone tissue and provides a comparison among isotropic homogeneous, isotropic inhomogeneous and orthotropic inhomogeneous material models and their impact on the results of the stress-strain analyses. In the thesis, there is also a short list of popular implants used in present times as well as a few examples of creating geometrical models of some prosthesis.
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Napjatostní analýza kyčelního kloubu s povrchovou náhradou - simulace chůze
Návrat, Tomáš ; Florian, Z. ; Fuis, Vladimír ; Štekl, M.
In the works dealing with computational hip join modelling, published on this subject in the past, the hip's loading is modelled so as to correspond to standing on one lower limb. At this standing, man remains symmetric at the considered level of resolution, and the force of gravity is identical with the body's axis. We consider the standing because man at walking always stands on one lower limb, and we suppose that, at this standing, in the hip joint there develops a maximum force (we do not suppose rapid walking or shock load). Since the computational models presented up to now consider the standing on one lower limb, it was decided to test computational modelling of even the step' next phase. The problem was formulated as follows: to make a strain-stress analysis of the hip joint with applied surface prosthesis for various phases of the step.
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Calculation of the Ceramics Material Parameters from the Testing Destructions of the Heads
Fuis, Vladimír ; Návrat, Tomáš ; Hlavoň, Pavel
This paper deals with increasing of the computation modelling level of the reliability problem of ceramic heads of total hip joint endoprostheses. The solution to this problem was invoked by recent more frequent failures of these heads in clinical practice. Results of computational and experimental modelling have shown a substantial influence of shape deviations in the conical connection between stem and head on the initiation of ceramic head fractures. The fracture probability was evaluated step by step for various macroscopic shape deviations in the conical connection and then for microscopic shape deviations superposed on the macroscopic deviations.
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Verification of Berghausen noise method for residual stress measurement
Krejčí, Petr ; Návrat, Tomáš
This paper deals with verification of Barkhausen noise method for residual stress measurement. The aim is to verify functionality of commercial equipment which is using Barkhausen noise method for residual stress measurement by simple experiment. The experiment was realized by means of equipment for material testing with ability to load test sample by simple tension with known magnitude.
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