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Resource Planning For Project Management
Ježek, Filip ; Valášek, Jiří (referee) ; Smolíková, Lenka (advisor)
The diploma thesis focuses on initial planning of human resources at quotation phase at enviroment of APV company, for purposes of project management. It analyse initial planning of projects and compare it with actual state at the end of project. It contains suggestion, which may lead to more accurate initial planning.
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Stress - strain analysis of save first molar tooth
Valášek, Jiří ; Fuis, Vladimír (referee) ; Florian, Zdeněk (advisor)
This diploma thesis specialises in stress – strain analysis of the save tooth. Concretely this thesis works with the save tooth with cavity of the I. and II. class. At the beginning of this work you can find description of basic filling materials, different ways of cavity´s preparation and subclassification of cavity. This work describes production of geometric model of health and save tooth with cavity of the I. and II. class. Model geometer of the save tooth was im-plemented in several ways, each one concerning different form of cavity, size of cavity and different filling materials. Final element net was created on the base of these geometric mo-dels. Computational model was created with the help of the programme ANSYS 11.0 in gra-phic environment Workbench and with the help of the final elements method. The results of the analysis are following: Continuity of the save tooth happens to break thereby the whole stiffness decreases in comparison with the save tooth. Two filling materials were used for sanitation of the tooth: amalgam and composite resin. As a result of the analysis I consider amalgam to be more suitable for sanitation of teeth in moral section.
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Biomechanical studies of knee jointarthroplasty
Zděblo, Jakub ; Valášek, Jiří (referee) ; Florian, Zdeněk (advisor)
The presented diploma thesis deals with stress-strain analysis of the intact human knee joint and the knee joint after reconstruction using fixation plate. Finite element method is used to determine the biomechanical response of the knee under loading with the FE software Ansys. The three-dimensional finite element model is consisted of bony structures (femur and tibia) which were created using computed tomography (CT) data, articular cartilages and both menisci. Model of the locking plate (LCP) was created based on producer's technical guide. Three models of the knee joint with LCP fixation plate are created for three different sizes of condylar fragment based on the intact model. On all variants is applied loading corresponding to maximum loading in a gait cycle. The results show that reconstruction of the knee joint with locking plate has no effect on changing in contact pressure on tibial plateau.
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Strain stress analysis of proximal femur with dynamic hip plate
Kohoutek, Jan ; Valášek, Jiří (referee) ; Florian, Zdeněk (advisor)
The presented Master’s Thesis aims at determining stress and strain distribution in proximal femur with applied PCCP and DHS systems. The DHS system has been widely and successfully used for treating intertrochanteric fractures of proximal femur; in some cases, however, complications concerning implant cut-out and excessive fracture collapse occur. To minimize the risk of stabilization failure, the PCCP system was designed. In the Thesis, the process of creating the numerical model is described and the results obtained by employing Finite Element Method are presented. The 3D models of implants’ geometry were created based on the real objects. The model of proximal femur geometry was built by utilizing a series of CT scans and divided into two bodies with respect to the AO classification afterwards. The loading was obtained by solving the static equilibrium equations for the loose lower extremity. The computation was run in Ansys Workbench v13 software. In the hip screws of the PCCP system, lower values of equivalent stress can be found when compared to the DHS system. However, the equivalent strain generated in the proximal fragment is 3-times higher when the PCCP system is employed than in case of DHS system which may be due to the self-cutting design of PCCP screws. By employing PCCP system, the risk of implant failure is decreased. On the other hand, the bone tissue of the proximal fragment in close vicinity of the implant screws seems to be overloaded and prone to collapse.
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Biomechanical study of the proximal part of the femoral intermedullary nail
Hrdlička, Jan ; Valášek, Jiří (referee) ; Florian, Zdeněk (advisor)
The presented Master Thesis is focused on the structural analysis of the proximal femur on which the Proximal Femoral Nail (PFN) and Proximal Femoral Tele-Screw (PFT) systems are applied. These systems are used for a treatment of the intertrochanteric and femoral neck fractures. However, in some cases a loss of stability of the systems may be expected. The presented thesis describes a development of numerical models in which stress distribution of implants and strain distribution of bone tissue are compared. Numerical models were created from real objects. The model of femur geometry was created by using the Computed Tomography (CT). Boundary conditions of the model were estimated from the force equilibrium of the lower limb. All numerical models were processed in the commercial package ANSYS Workbench v15.0. It is shown that the hip screws of the PFN system result in lower equivalent stresses than the screws of the PFT system. Maximal strains of the bone tissue, when using the PFN system, are situated near the fracture, close the hip screw thread. For the PFT system, the maximal strains are only near the area of fracture.
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Research study of mechanical properties of cranial tissue
Wojtek, Lukáš ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This bachelor thesis deals with the problematics of determining mechanical properties of cranial bone tissue. In this thesis a search study associated with an experimental determination of mechanical properties of bone tissues is executed. A brief history and progress of imaging methods and their importance of computation modelling are introduced. There are descriptions of histomorfometric parameters describing a structure of bone tissue at the micro level, ways of their computation and their impact on mechanical properties of bone tissue. Practical part of the thesis is focused on processing micro-CT images of cranial bone as well as analysing histomorfometric parameters (BV/TV, TbTh, TbSp) and subsequently stress strain analysis of selected sections of cranial bone tissue. Resulting Young´s modulus of elasticity of bone tissue [MPa] are compared with results from experiments from literature.
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Strain-Stress analysis of pig femur
Legerský, Radek ; Valášek, Jiří (referee) ; Florian, Zdeněk (advisor)
This master’s thesis deals with the strain-stress analyses of the pig femoral bone in physiological and pathological condition. Pathological condition is determined by a significant defect in diaphysis of the bone fixed by using direct angular stable locking plate with screws. The thesis describes the creation of computational models with special focus on bone tissues models of material, which are based on analysis of digital images from computed tomography (CT). There are created and analyzed three types of computational models: the first one corresponds to physiological condition of femur, the second one to femur with significant defect and fixation plate and the third one to femur with significant defect, fixation plate and rod. Every model is loaded in three ways: the first of them simulating the experimental conditions of pressure testing of the femur, the second one bone stress in the sagittal plane and the third one stress by using load determined from probational release of the pig hind limb. Strain-stress states are determined by finite element method using Ansys computational system. Gained results of stress and strain are compared with experimental measurements. The thesis presents a basic idea of the mechanical behavior of porcine femur and porcine femur with significant bone defect.
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Controlling in EUROTEC
Valášek, Jakub ; Dostálová, Eva (referee) ; Režňáková, Mária (advisor)
This thesis evaluates state of controlling systém in company Eurotec, k.s. On the basis of this analysis suggests future development of controlling systém and suggestions for introduction of controlling reporting system and systém of planing.
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Stress-strain analysis of spinal segment with fixator
Mach, Ondřej ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This Master’s thesis deals with strain-stress analysis of a spine segment with an introduced fixator and a spine in natural physiological state. The work starts with a research study of literature sources that focus on similar issues. Furthermore, basic anatomy terminology and basic procedures for human spine stabilization were described. The formulated issue was resolved by computational modelling with the use of the finite element method. This solution requires a suitable computational model to be produced. This model consists of partial geometry, material, bond, and loading models. The geometric model was produced on the basis of CT scan images of a 60-year-old man which were used for producing five spine vertebrae T11–L3. Moreover, the geometric model consists of four intervertebral discs and eight articular cartilages. The material model includes homogeneous, heterogeneous and degraded properties of bone tissue. The strain-stress analysis was performed for seven loading states, which concern basic movements of human spine – standing, bending forward, bending backwards, bending left, bending right, left rotation and right rotation, with the use of ANSYS software. The assessed and analysed quantities include spine segment displacement, contact pressure of articular cartilages and stress on the fixator.
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Stress-strain analysis of mandible with applied fixator due to the missing bone tissue
Fňukal, Jan ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This thesis deals with the fixation of lower jaw with bone tissue defect using commercially produced fixator. Large defects of bone tissue are mainly caused due to the removal of bone tissue affected by tumor. These topics have been researched on the basis of the literature. Subsequently, stress strain analysis of the lower jaw with the applied fixation plate was performed. This analysis was solved by using computational modeling with variational approach, ie the finite element method. The work also describes in detail the procedure of creating model of geometry, model of material, model of boundary conditions and loads with subsequent solution of several computational models. The stress strain analysis was done for lower jaw with varying size of the removed bone tissue with applied reconstruction plate made of CP-Ti Grade 4 and for the lower jaw with the plate, which is made of -Ti-Mo. Finally, the influence of the mechanical properties of the callus during formation of new bone tissue (callus healing) on the stress and deformation of the solved system was evaluated.
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