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Design of machining process diagnostic system
Wolf, Jonatan ; Klapka, Milan (referee) ; Houfek, Lubomír (advisor)
The master’s thesis is focused on online diagnostics of the machining process. In the theoretical part are presented maintenance possibilities of machine tools. A whole chapter is devoted to vibrodiagnostics, which describes vibration sensors, their attachment to the measured object and methods of vibration signal processing. The practical part lies in creating a software diagnostic solution for chosen PLC and sensors. The functionality of the proposed system was verified during experimental machining, which also provided valuable data for the correct setting of the system.
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Simulation model of ABS in passenger car
Svobodová, Jana ; Houfek, Lubomír (referee) ; Grepl, Robert (advisor)
The development of electronics caused revolution the automobile industry. Antilock-Brake-System have become a milestone in the development of electronic security systems. ABS detects susceptibility to locking the wheels, which may occur during braking for critical driving conditions, and then hits. Using of simulation programs is another milestone. Simulation allows repeating of tests and find the best solution of the problem before introduction in practice. Time and development costs are then significantly reduced. In the work is described the most important component of security systems - the braking system and the entire braking process of ABS system. With using a mathematical description of the wheel is in the Matlab-Simulink made quarter model of the vehicle to simulate driving conditions and then created to it a system of ABS. At the end is there an assessment and graphically shown the results of simulations braking.
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Utilization of multi-body simulation tools in subject Dynamics
Lokšeninec, Ľuboš ; Houfek, Lubomír (referee) ; Březina, Lukáš (advisor)
The bachelor’s thesis is conducted in purpose of modernization the dynamics theory teaching methods by the multi-body simulation systems. Thesis acquaints student with accessible simulation systems and provides a manual how to compose virtual models of physic frameworks. Student is introduced to the basic options of current multi-body system by means of pre-processed examples focused on rolling, oscillation and inertia moment. Thesis refers to present teaching methods with models composed in Matlab/Simuling system with SimMechanics sublibrary.
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Design, production and testing of education model "Watt's regulator"
Janoš, Petr ; Houfek, Lubomír (referee) ; Grepl, Robert (advisor)
In the thesis I deal with design, production and testing of laboratory education model "Watt‘s regulator". This work considers different solutions of construction and especially the role of sensors. I assess positives and negatives of each solution. In addition, I describe design and implementation of electronics and wiring for the communication with a PC via control card Humusoft MF624. Using the MATLAB-Simulink and its extensions Real Time Toolbox 4.0 I make the proposal of PID regulator based on Ziegler – Nichols method.
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Stress analysis of rotor packet of synchronic generator
Bureš, Jiří ; Houfek, Lubomír (referee) ; Petruška, Jindřich (advisor)
This diploma thesis deals with distribution stress and strain of sheets metal of rotor packet and in critical locations of supporting bars of synchronous generator. These variants are calculated and one another comparison of analytic calculation results, numeric calculation of 2D model and numeric calculation of 3D model in three vriants ( with bars of rectangle section, circular section, with upper radius). The calculation include influence of thermal expansion, centrifugal force, interference of the packet on the shaft and prestress in the axial direction of bolt. To creation of geometric model and numerical calculation is used program ANSYS 11.
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Application of DIC method for measurement of deformations on small specimens
Vejchoda, Ondřej ; Houfek, Lubomír (referee) ; Návrat, Tomáš (advisor)
This diploma thesis tries to find the most suitable optical system for measuring deformation displacements on the surfaces of bodies. The first chapter describes the systems and methods that will be used. The second chapter is devoted to the design of the experiment. It describes the preparation of the experiment from the point of view of software and hardware and what are the important preliminary preparations. The last chapter contains the results of experiments and evaluation of the systems.
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Optimization analysis of brake wheel
Hrabovský, Jozef ; Vlach, Radek (referee) ; Houfek, Lubomír (advisor)
Subject of this diploma thesis is break wheel optimalization analysis. Break wheels are used in mountain bike downhill races in extreme conditions. It is the first product of this type of an emergent company that was made by the use of intuitive approach. The reason for optimalization is improper behavior of existing solution that occurred during testing. This optimalization consists of finding and analyzing existing characteristics, deciding which factors influence this improper behavior, suggesting new solution and verification of this solution. Break wheel characteristics were detected in an experiment. For realization and evaluation of this experiment, a method named Design of experiments, was selected. This method is used for elaboration of results coming from the Regression analysis. It is possible to effectively achieve the result data by using this procedure. The experiment was oriented to gain data of temperature behavior of break wheel during real load. Mathematical model was adapted on the basis of this data and finally, the calculation was made by the use of Final element method by ANSYS WORKBENCH. Calculations were also coordinated through Design of calculation, and were oriented on temperature deformation and stress. Solution achieved by the Final element method, was evaluated by the Regression analysis and served as a proposition for a new break wheel construction.
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Application of ductile fracture models in computational simulation of manufacturing operations
Hůlka, Jiří ; Houfek, Lubomír (referee) ; Petruška, Jindřich (advisor)
This diploma thesis is an introduction to the ductile fracture under large plastic deformations and is focused to numerical simulation of this type of problems. Explicit finite element method (FEM) is discussed in theoretical introduction as the most powerful tool for numerical calculations in this area. Actual state of research and possibilities of ductile fracture simulations are presented. Applicable fracture criteria are collected in a summary sheet and the most important ones are selected and commented in detail. The problem of implementation of selected criteria into commercial FEM packages is discussed, too. Main part of the work is presented in chapters 7÷9 where two ductile fracture criteria (Equivalent Fracture Strain and Johnson-Cook) are applied to numerical simulation of material cutting. All results were obtained with ABAQUS/Explicit 6.5.1 and their verification was realized by experimental measurement.
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