Přístupnostní navigace
E-application
Search Search Close
Branch Details
Original title in Czech: Inženýrská mechanikaFSIAbbreviation: D-IMEAcad. year: 2009/2010
Programme: Applied Sciences in Engineering
Length of Study: 4 years
Accredited from: Accredited until: 1.3.2012
Profile
The Ph.D. study focuses on the following fields of mechanics: · Mechanics of solids. Theory of modelling mechanical systems, constitutive material relations with emphasis on non-linear behaviour, limit state conditions of materials and structures, mechanics of composites, biomechanics, analysis of stress, deformation and dynamic behaviour of selected groups of bodies (including composite bodies), inverse problems of mechanics of rigid bodies, modelling of stress and deformation in selected technological processes (forming), theory of experiments in interactive driving and mechatronic systems, dynamic of vehicles and of machinery, solution of selected problems in vibroacoustics. · Mechanics of liquides and gases. Flow theory of compressible and incompressible fluids. Flow of gases and vapours. Nonstacionary flow and impact. Orientation on the flow in hydralic machines and heat engines. · Thermomechanics. Theory of heat and substance transfer. Application of interferometry and other modern experimental methods. Thermodynamic problems of metallurgy and foundry technologies and heat treatment. Applications in the field of design of thermal power-generating machines. Inverse problems of heat transfer.
Issued topics of Doctoral Study Program
The function of human hearing organ is generally described as moving mechanical system. Actual computer systems enable to perform the computer simulation of the sound signal transmission from external air medium to fluid medium in the inner ear with the consideration of all fluid-structure interactions, the FEM or BEM are most frequently used for this purpose. The complete FE model of normal human ear has been developed at UMTMB. The principal aims of this work will be the amelioration of this FE ear model and the application of this model for sound transfer characteristics calculations when different types of earphones are inserted.
Tutor: Pellant Karel, doc. RNDr., CSc.
The objective of the assignment will be to obtain new findings concerning transfer phenomena during crystallization and cooling of concast significantly rectangular-profile steel slabs inside a caster. It will be necessary to establish a dynamic model of the transient temperature field that will analyse the process and in real time, or even shorter. This model will contain a program for scanning all real operational parameters. On the interface of this program, the calculation of the temperature field of the slab will be confronted with the operational parameters that are measured on-line. After determining the limit values of the decisive output parameters, a system will be set up for the control of the caster depending on the current state and recommended limit values. The model is to be integrated into the information system of the concasting technology at VÍTKOVICE STEEL, a.s.
Tutor: Kavička František, prof. Ing., CSc.
The variation in mechanical properties or in the shape of individual ear parts can simulate the influence of different ear diseases or different ear pathologies on hearing. The studies of the efficiency of invasive surgery interventions in external or middle ear region will be executed. The results of modelling will be compared with audiological investigations of patients.
The use of FME is possible for the studies of sound transmission via human ear. When the mechanicle conection between eardrum and inner ear is interrupted, the ossicle chain prosthesis are applied. The analysis of the influence of fixation plosition, mode of fixation and mechanical properties of prosthesis on sound transmission characteristics of reconstructed ear will be discussed.
Review of the state of art from the area of robot motion planning in a scene with obstacles which can be static or dynamic, the scene need not be known and size of robot and its motion contraints must be considered (direction changes, rotation etc.). Application of modern methods of computational geometry and their structures (Voronoi diagrams, Delaunay triangulation, visibility graphs) and stochastic heuristic methods with a support of approximate reasoning. Implementation of algorithms for 2D and 3D scene and different types of robots. Analytic expression of time complexity of proposed algorithms and comparison of their efficiency depending on problem specific constraints (e.g. motion only in 8 directions) and size of data structures.
Tutor: Šeda Miloš, prof. RNDr. Ing., Ph.D.
In area of intelligent robotic systems it's very important to use feedback of environment to machine. A machine possibility to recognize of biological entity is desired. The aim of the work will be theoretical design and real application for intelligent robotics. In the design context image processing methods and artificial intelligence methods (artificial neural networks, fuzzy-neural networks etc.) are supposed. Simulation modeling and optimization in Matlab environment are recommended.
Tutor: Ošmera Pavel, prof. Ing., CSc.
a
Tutor: Florian Zdeněk, doc. Ing., CSc.
The objective of the thesis is a crack growth analysis along the crack interface between mismatched composite materials consisting of a ceramic matrix reinforced by various types of fibres, particles including piezoparticles capable of self-diagnostic function. Both sharp and smooth transition between two layers will be considered. For smooth gradient transitions micromechanical models will be suggested. Within the thesis framework a computational FE model based upon the principles of two-parameters linear fracture mechanics will be created. Theoretical predictions will be compared with experimental data obtained by Brittle Fracture Group, Institute of Physics of Materials ASCR. It is also expected that the results of molecular dynamics simulations of interface performed at the Lund University will be employed
Tutor: Kotoul Michal, prof. RNDr., DrSc.
Theme of the dissertation will be the formulation of reliable computational models of high velocity material fracture, their implementation into the FE packages and application to typical problems of impact loading like car crash, drop or penetration tests. Material failure criteria of the computational models will take into account basic processes on the structural level like localization of plastic deformation and formation of adiabatic shear bands. Correspondence between the computational prediction and experimental results will be analysed to judge practical application of suggested models. Results will be formulated as a proposition of approach to typical impact problems, acceptable as a practical calculation tool for industrial applications.
Tutor: Petruška Jindřich, prof. Ing., CSc.
The theme is focused on a very actual topic of biomechanics, i,e, computational modelling of stress-strain states in isolated smooth muscle cells during their mechanical tests. The results obtained from the biomechanical laboratory of prof. Hayashi at Okayama University of Science in Japan, as well as experimental data from literature will be used for verification of the models.The computational model comprehends internal cell structure (nucleus, cytoplasm, membrane, cytoskeleton) and parameters of the components should be identified on the base of mechanical tests of cells and their components. The model will then be used for evaluation of stress-strain states of cells in the vascular wall. Changes of stress-strain states of cells in the vascular wall influence biochemical (physiological as well as pathological) processes in the wall so that their knowledge can contribute to investigation of fundamentals of atherosclerotic and remodelation processes in the vascular wall.
Tutor: Burša Jiří, prof. Ing., Ph.D.
Application of system methodology for mechatronic design of hydrostatic guide for linear axes of large and heavy machine tools. Especially increase of guides accuracy through real-time compensations of deformations (esp. thermic, deformations from technologic forces, deformations caused by workpiece dead load, etc.) by means of variable pressure in hydrostatic pockets will be considered.
Tutor: Březina Tomáš, prof. RNDr. Ing., CSc.
Application of system methodology for mechatronic control design with maintaining of optimum operation mode of a swirl turbine. The speed regulation of the swirl turbine will be especially considered with respect to headwater as well as tailwater level, and to the eventual impacts on space and functional integration of the device. Collaboration with industry.
Stress-strain Analysis in the Wheel.
Tutor: Janíček Přemysl, prof. Ing., DrSc.
In a majority of structural components, the stress state is different from the homogeneous uniaxial tension or compression, typical for fatigue testing in laboratories. Therefore, biaxial fatigue tests start to be used more frequently in the last years. In the last years, the world research has produced a number of new and improved criteria for multiaxial fatigue life based on continuum mechanics.Consequently, there is a wide field for their verification and improvement. In the Czech Republic, however, this research is only in a pioneering stage. The work will be focused on the application of multiaxial fatigue criteria for prediction of fatigue life in metallic materials loaded under combined bending and torsion. The research is supported by a Grant of the Czech Science Foundation. The Phd student will attend international scientific conferences and summer schools focused on multiaxial fatigue and fracture of materials.
Tutor: Pokluda Jaroslav, prof. RNDr., CSc.
The advanced polymer structures contain material interfaces, which can influence its final lifetime. Important topic of the research is than study changes of the crack behaviour due to material nonhomogeneity. Therefore, general goal of the project lies in the development and suggestion of reliable techniques for estimation of a residual life time of multilayer polymeric structures. Slow crack growth, which can be described by the corresponding fracture mechanics parameters, plays an important part in this estimation. In the case of viscoelastic polymer materials the current methodology will be developed. The correlation between the experimental data and results of relevant numerical model will be presented. The results enable to estimate material's composition with respect to the optimal mechanical properties of multilayer structure.
Tutor: Hutař Pavel, prof. Ing., Ph.D.
The work will be focused on research and development of nonlinear control algoriths which use the dynamical model of the system. The simulation modelling in Matlab+ environment is supposed to use as well as experimental work with Real-Time Rapid Prototyping hardware dSPACE, which is currently de facto standard in automotive industry. Theoretical results will be practically verified on particular real servodrives with DC motors used in automotive (throttle, REA).
Tutor: Grepl Robert, doc. Ing., Ph.D.
The work will be focused on research of new methods for the control of wheeled vehicles which is recent industrially and scientifically interested topic applied e.g. in traction algorithms in car (ABS, ASR). The simulation modelling in Matlab+ environment is supposed to use as well as experimental work with Real-Time Rapid Prototyping hardware dSPACE, which is currently de facto standard in automotive industry. Designed simulation models will be based on both holonomic as well as nonholonomic kinematics. Theoretical results will be practically verified on particular real model of four wheeled vehicle.
Tutor: Horský Jaroslav, prof. Ing., CSc.
Manage of the design, optimizing and its experimental verification of the turbochrgers wirth journal and thurst bearings. 1. Design of the journal bearings with fixed segments. 2. Computational analysis the rotor systems with these bearings. 3. Experimental verification of the design.
Tutor: Malenovský Eduard, prof. Ing., DrSc.
The problems of mechanics of hyperelastic materials are motivated by the possibility of computational assessment of reliability of tyres. The objective is to increase the level of computational modelling of stress-strain states and failures in steel-rubber composites. As no generally acceptable failure criterion has been fomulated till now, not only for elastomers, the first step is the verification of suitable constitutive models, then the description of failures of elastomers; the failure mechanisms depends on the type of the stress state. A criterion of failure of elastomers under statical load proposed by the supervisors recently requires a comprehensive experimental-computational modelling to be verified or falsified. To achieve this, enlargement of knowledge on material characteristics of components of these gradient materials is necessary.
Advanced structures are often created by composite materials with interfaces, which can influence their service lifetime. As an example can be introduced e.g. multilayered polymer composites applied as water or gas pressure pipes or layered ceramics. The aim of thesis is determination of interface influence in layered materials on their failure conditions, crack propagation and eventually residual fatigue lifetime. PhD student will contribute to develop of suitable procedure for determination of interface influence on lifetime of composites. For necessary numerical calculations FEM system Ansys and mathematical software Matlab will be used.
Tutor: Náhlík Luboš, prof. Ing., Ph.D.
Subject of the dissertation will be the analysis of ductile fracture criteria, existing now in commercial FE programs, evaluation of their theoretical background and practical applicability for material damage prediction in various forming and cutting operations. This stage will be the basis for implementation of modified damage criteria, suitable for simulation of fast dynamic processes solved by explicit FEM, which is necessary for development of simulation modelling of material forming, cutting, sawing and machining. Attention will be given to calibration of necessary material parameters of selected criteria, too.
Thesis will be focused on: 1.Detailed background research about noise of computers and how it varies with operating conditions 2. Development of FE model of one computer 3. A controlled theoretical and experimental study of the noise emission of a typical model of computer (system Ansys, Sysnoise or SEADS will be applied). The study of the efficiency of possible noise control arrangement (application of absorptive surfaces, the diminution of cooling fan diameter, the change of fan blade, the application of sound screening of fans etc.) 4. Specification of the efficient noise control arrangement of computers
The problem of noise is very oft-discussed problem in buildings. As the stage of personal lifts in CR does not correspond to the contemporary EU limits, the reconstruction of the personal lifts is actual. The study of the efficiency of possible noise control arrangement (application of absorptive surfaces on the engine room walls, the application of sound screening of the motor, the application of gum elastic underlays etc.). The application of mathematical modelling using SEA method (statistical energy analysis) or FEM is supposed for discussions of suggested noise control measures.
Tutor: Raudenský Miroslav, prof. Ing., CSc.
The objective of the assignment will be to obtain new findings concerning transfer phenomena during crystallization and cooling of concast massive steel billets and rounds inside a caster. It will be necessary to establish an off-line and on-line model of the transient temperature field that will analyse the process and - in the case of the on-line model - in real time. The models will be corrected and verified via experimental measurement directly in the operation. The model is to be implemented for the optimization of the concasting technology at TŘINECKÉ ŽELEZÁRNY, a.s.
Strength optimization of the composite material structure at selected machine part.
Tutor: Vrbka Jan, prof. RNDr. Ing., DrSc., dr. h. c.
The theme is focused on a very actual topic of biomechanics, i,e, computational modelling of stress-strain states occuring in aneurysms of abdominal aorta and some of the brain arteries. The shape of the arterial wall shows irregular geometry that is defined on the base of CT scans of real patients.Further it shows non-linear constitutive dependencies under large strains, for which some special constitutive models have been implemented in ANSYS. The geometry as well as material parameters of the arterial tissues are changing as a consequence of pathological processes what influences substantially the stress-strain states in the wall. Computational models wil be used in the expected proposal of criteria for assessment of rupture risk of the aneurysm.
The methods of mathematical modelling (Multibody systems) will be applied for the optimalisation of distribution system of the motor Zetor type UŘ3. Existing computer systems (Pro-engineer Wildfire3, MSC Adams, CFD Fluent) will be applied for this purpose. The achievement of the maximal engine power and the minimal jumps of inertial forces will be used as main criteria for the determination of the optimal valve timing. The results of mathematical modelling will be compared with experimental measurements (laser interferometry) on the model.
Microlaminate systems are an attractive class of microstructures for engineered materials due to the natural tendency of some materials to form laminate structures and since multilayer structural toughening is an effective toughening mechanism. Microlaminate structures are utilized to in many electronic and structural applications such as MEMS. The objective of the thesis is to develop a computational model of crack propagation through microlayers. A particular attention will be devoted to the analysis of the transition of crack across the sharp material interfaces. Moreover, high residual stresses developed in individual layers will be taken into account. In case of smooth transitions, Betti's-Rayleigh reciprocal theorem in conjunction with FEM will be employed for the calculation of both, the stress intensity factors and the T-stress. A novel approach will be based upon non-equilibrium auxiliary stress field which implies retaining a domain term in Betti's-Rayleigh reciprocal theorem. Theoretical predictions will be compared with experimental data obtained by Brittle Fracture Group, Institute of Physics of Materials ASCR. It is also expected that the results of molecular dynamics simulations of interface performed at the Lund University will be employed.
Theme of the dissertation will be the computational analysis of transient thermal stress problems in both rolls and rolled products. Aim of the dissertation is to provide reliable computational models of thermal, stress and deformation fields that could be used for prediction of service life, dimensional stability, residual stress and mechanical properties of both the tool and product of the rolling process. Computational models will be verified by experimental data in cooperation with the Heat transfer laboratory of Faculty of Mechanical Engineering, BUT. They will be further used for optimization of the rolling mills cooling.
Study plan wasn't generated yet for this year.