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Deformační analýza trabekulární kosti za použití mikrotomografie v čase
Jiroušek, Ondřej ; Zlámal, Petr ; Kytýř, Daniel ; Kroupa, M.
To explore the possibilities of modern X-ray detectors an experimental setup with trabecular bone sample under uni-axial load in special loading device enabling time-lapse tomography was used. The load was applied gradually and after complete tomographic scanning the deformed shape was reconstructed. Collected 3-D images help to study the deformation process of the micro-structure where collapsing of individual trabeculae can be observed and compared to finite element simulations.
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Kalibrace konstitutivního modelu trabekulární kosti na základě nanoindentace
Zlámal, Petr ; Jiroušek, Ondřej ; Němeček, J.
The paper deals with investigation of a trabecular bone behaviour during nanoindentation test. Behavior of trabecular bone is investigated using real nanoindentation and finite element simulation. Two different plasticity criteria for material model of trabeculae are tested, namely von Mises and Drucker-Prager. Von Mises criterium is extended bilinear isotropic hardening. Constants needed for numerical material model are obtained from fitting procedure of a experimetal load-displacement curve.
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Zjišťování mikrostrukturálních vlastností acetabula lidské pánve pomocí mikro-CT
Kytýř, Daniel ; Jiroušek, Ondřej ; Vavřík, Daniel
The paper deals with microstructure investigation of trabecular bone in acetabular region. Trabecular bone microstructure is the main factor of the bone quality and mechanical propertites at macroscopic level. Data from high resolution micro Computed Tomography can be used to reconstruct the complex geometry of the trabecular bone inner structure and interface between bone and implant. The data are usable as for micro-FE modeling as well as for experimental loading tests evaluation.
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Zjišťování materiálových vlastností houbovité kostní tkáně optickou metodou
Kytýř, Daniel ; Jiroušek, Ondřej ; Žák, Ondřej
Article deals with material properties of spongy bone assessed by optical identification based on surface texture registration.Strains at the specimen surface were measured using high-resolution CCD camera and optical identification method was used to trace their position during deformation. Centres of gravity of the markers are then considered to be vertices of connected triangles for which fields of displacement and strain are calculated. The assessed displacements of the structure of trabecular bone are used to obtain strain-stress diagram.
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