National Repository of Grey Literature 154 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Stress-strain analysis of Kozlov lookout tower
Winter, Josef ; Vaverka, Jiří (referee) ; Fuis, Vladimír (advisor)
Bachelor thesis is aimed at stress and deformation analysis of strut frame. The object of interest is lookout tower Kozlov close to the city of Česká Třebová in region of Ústí nad Orlicí in Pardubice Department. The main aim is to simplify 3D model of strut frame and its analysis. At the beginning I deal with history of lookout towers, theoretical introduction of bar, strut frames and limit states. Then follows modelling of 3D model with modified topology of bars and following calculation for different static loading and calculation for static determination. At the end numerical calculation was done to compare chosen model with analytic solution.
Mechanical analysis of lift
Tesař, Jakub ; Kovář, Jaroslav (referee) ; Fuis, Vladimír (advisor)
The bachelor thesis deals with analysis of the system with seven solids with consideration of passive effect. In the first part of thesis describes the basics of statics and dynamics. Description of neutral and passive links, release method and reduction method. In the second part of the work are describing effects of passive effects on the movement state of the elevator. The individual bodies were released in the GeoGebra program. The aim of the example is to determine the contract forces in the links, check functionality of the links and state of motion. The solution took place in the computer program Matlab
Stress-strain analysis of a crane arm
Mora, Lukáš ; Halabuk, Dávid (referee) ; Fuis, Vladimír (advisor)
The content of this bachelor’s work is a summarization of types of tower cranes and subsequent stress-strain analysis of the crane arm of the crane type 150EC-B8 Litronic located on the Šumavská street in Brno. Analytical stress-strain analysis is calculated with equations of equilibrium using joint method in various types of loading of the construction with MAPLE software. Numerical calculation is executed on 3D model of the construction in software ANSYS. The aim of this bachelor work is the verification of the correctness and comparison results of analytic calculation with numeric calculation and evaluation of the results from a limit states and deformation standpoint.
Radial turbine runner design with reduced moment of inertia
Votava, Ondřej ; Skalka, Petr (referee) ; Fuis, Vladimír (advisor)
This master’s thesis deals with topological optimization of the impeller of a radial turbocharger turbine. It focuses on reducing the moment of inertia with unchanged aerodynamic properties. The optimization was carried out using CFD, thermal and structural analysis. The computational modeling was performed using the finite element analysis in ANSYS. The work proposes models of the impeller with the topological modification of the internal structure. Based on the values of moment of inertia, the stress and the strain the most suitable model was selected.
26th International Conference Engineering Mechanics 2020
Fuis, Vladimír
The proceedings of the 26th international conference Engineering Mechanics contains 129 papers from the following section: Biomechanics, Dynamics, Fluid Mechanics, Fracture Mechanics, Kinematics, Mechanics of Solids, Mechatronics, Reliability of Structures, Technological Processes, Thermomechanics.
Influencing the Indentation Curves by the Bluntness of the Berkovich Indenter at the Fem Modelling
Kovář, J. ; Fuis, Vladimír ; Tomaštík, J.
The influence of the Berkovich indenter bluntness on the indentation curves at nanoindentation test of fused silica is determined by the FEM (finite element method) in this paper. The Berkovich indenter, which is mostly used for the nanoindentation test, was assumed for calculations. The indenter is always blunted in real tests. The bluntness of the indenter has an influence on the results of the nanoindentation test. The combination of the nanoindentation test and the FE modelling can be used for the calculation of the parameters of fused silica plasticity and estimation of the bluntness of the indenter. In this paper, the FEM was used for calculating of the indentation curves. Two cases of bluntness were assumed. The curves for ideally sharp or blunted indenter were determined. The results of these calculations showed that the indentation curves are dependent on the bluntness of the Berkovich indenter. The greatest relative influence of the nanoindentation curves by the bluntness is in the area of small values of the indenter displacement. The impact of assuming blunted indenter to calculated parameters of plasticity was assessed. It is often difficult to measure the bluntness of the indenter but it has an influence on the results of the nanoindentation test and should be included into calculations to make it more precise.
FEM simulation of the nanoindentation test with rigid non-rigid indenter
Kovář, J. ; Fuis, Vladimír
This paper focuses on the comparing of the results of the FEM simulations of fused silica nanoindentation tests. Fused silica is modelled like bilinear elasto-plastic material with the parameters estimated from the experiment. FEM simulations are made with the 2D axisymmetric conical indenter which is equivalent to the Berkovich indenter and the indentation curves are evaluated. The FEM simulations were made with the rigid and the non-rigid indenter and the difference between the indentation curves obtained with these models is assessed. The evaluated indentation curves are compared with the indentation curves obtained from the experiment.
Sensitivity Analysis of the Material Parameters Obtained from the Measurements
Fuis, Vladimír
The paper deals with sensitivity analysis of the material parameters of the ceramic material on the dispersion of the measured data from the sensors. Material parameters of ceramic material are calculated from a set of destruction tests of ceramic heads of total hip joint replacements. The standard way of calculation of the ceramic material parameters consists in carrying out a set of 3 (or 4) point bending tests of specimens which were cut out from parts of the ceramic material to be analysed. In case of ceramic heads of the prosthesis, it is not possible to cut out specimens of required dimensions because the heads are too small. On that score, a special testing jig was made, in which 40 heads were destructed. From the measured values of circumferential strains of the head’s external spherical surface under destruction (by the sensors – strain gauges), the state of stress in the head under destruction was established using the finite elements method. From the obtained values the material parameters of the ceramic material were calculated using Weibull’s weakest-link theory. The calculated material parameters (Weibull modulus m and normalized volume strength σo, the last material parameter – stress σu is assumed to be equal 0 and corresponds to the conservative approach) has the dispersion and the influence of this dispersion (in our case the dispersion ± 5 % is assumed) is analysed in detail.
Comparing the Results of Probability of Ceramic Head Fracture According to Weibull's Theory with Inclusion of One or Three Principal Stresses
Kovář, J. ; Fuis, Vladimír
This paper focuses on the assessment of probability of ceramic head hip joint endoprothesis fracture.\nThe Weibull's weakest link theory with inclusion of one or all three principal stresses was used for calculations of probability of failure and the results were compared. The test of head of the hip joint endoprothesis according to ISO 7206 was modelled. Three variants were considered. In the first variant, the head of hip joint endoprothesis ended up without any imperfections from ideal geometry. In other two variants, the ceramic head had shape imperfection from nominal conicity. Principal stresses needed for the calculation of probability of failure were calculated by finite element method. The results with the use of linear and quadratic solid elements were compared and better option was chosen for the next calculations. The influence of allowed penetration, density of the mesh on the results of stresses and probability of failure was assessed. The Gaussian quadrature of 13th order was used for integration over the surface of unit hemisphere in space of principal stresses which was needed for computation of probability of failure with inclusion of all principal stresses. The influence of imperfection from nominal conicity on probability of failure of the head hip joint endoprothesis was calculated and the relative difference between the results of Weibull's weakest link theory with the inclusion of one or all three principal stressed was analyzed.
Comparison of hemispheric and conical cup in the total trapeziometacarpal joint replacement
Kukučka, Ivan ; Švancara, Pavel (referee) ; Fuis, Vladimír (advisor)
This diploma thesis deals with the comparison of total replacement of a trapeziometacarpal joint with a hemispherical cup and replacement of the same joint with a conical cup. In both cases of implants, these are types of replacements with dual mobility. The focus of the diploma thesis is the comparison of the transfer of forces from the head of the prosthesis to the trapezius bone through the different shape of the cup. The work was processed using computer software ANSYS Workbench 19.3.

National Repository of Grey Literature : 154 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.