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Chain Drive Computional Model as Virtual Engine Module
Vlastník, Jan ; Štětina, Josef (referee) ; Dundálek, Radim (referee) ; Píštěk, Václav (advisor)
his work deals with the methods of creating computational models for the analysis of the chain drive of camshafts in combustion engines. Methods are compared of the simulation of the drive mechanism; a new method is also presented for the simulation of the tensioning and guide bar by means of a modal reduction of an elastic body in the Multibody system. The work describes individual parts of the chain gear and the mathematical formulation of differential equations of motion. Algorithms are also indicated describing the mutual interaction of bodies in contact. Computations are here described for the determination of individual parameters necessary for setting up a chain drive model. The tensile characteristics of the chain is determined by the FEM programme. The chain model is analyzed in several alternatives of arrangement. FEM calculations are described here of the rigidity of contacts between the chain and the chain wheels and between the chain and the guide bars. The computational model has been created in the MSC ADAMS programme. The computation is carried out for a stabilized speed of the crankshaft of 3,000, 4,500 and 6,000 rpm and for a continuous start from the idle state up to the speed of 6,000 rpm with a constant load of the crankshafts by the torsion moment. Computation is also carried out for loading the crankshafts with a torsion moment deduced from the cam shape. The courses of the quantity obtained are processed by means of FFT; Campbell diagrams have been constructed for their evaluation. The results have been compared with the modal analyses of the individual parts of the chain gear for the determination of their mutual interaction.
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Interier Vibration Analysis of Moving Train
Železník, Gabriel ; Lošák, Petr (referee) ; Hadaš, Zdeněk (advisor)
In this work, a multibody system of a passing train on a railway is created. The model is focused on the vibrations, which are related to defect conditions. The subject of this work is to investigate the effect of vibrations in the interior of a rail vehicle. In the first part of the work, research of published dynamic models is performed. Various options for track and train modeling are described. Furthermore, the research presents several solution methods that can be used to simulate the moving train. Based on the research, the structure of the model and the method of solution were determined. The main areas of interest are the track, on which vibrations occur in contact with the wheel, and the car body, in which the vibrations will be further analyzed. For this reason, both parts were modeled as flexible bodies. The assembled model uses finite element discretization to describe flexible bodies. The time domain simulation is done by using generalized coordinates and modal superposition. The work describes the construction of the model in detail. The whole model is written in the Matlab and all codes are part of the appendix. The model allows change of all the parameters of the track and the car, including their geometric dimensions. The model includes 4 excitation mechanisms simulating the following defects: flat wheel, lifted sleeper, damaged sleeper and rail wear. After the model algorithm is fully described, the simulations without any defect are performed and a behavior of each system component is described. Finally, simulations of defect conditions are performed. Thanks to the combination of all defect conditions the response of the car body for the analysis of vibrations in the interior is compiled. In the last part, the compiled response in the frequency domain is used for the analysis of random vibrations in the vehicle interior in the Ansys environment. A 3D model of the train's ceiling paneling is used for the analysis, on which the effects of static and dynamic loads are compared. The area with the highest stress was determined by random vibration analysis. In the end, the modification of the part is proposed, which leads to the improvement of the strength properties of the assembly.
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Formula Car Front Wheel Carrier Simulation Analysis
Gach, Jakub ; Porteš, Petr (referee) ; Ramík, Pavel (advisor)
This Master’s thesis is focused on the suspension of the front wheel, more accurately for specific part, upright. It describes the basic requirements for construction, distribution of uprights, their method of production and types of materials used. It briefly mentions topology optimization and its two optimization methods. Also deals with vehicle dynamics for driving conditions – standing vehicle, braking and cornering. In the practical part, the work is focused on determining the load effects on the upright during the aforementioned driving conditions using MBS software. At the end of the work, FEM stress and deformation analyses are performed for loading on the wheel side and on the suspension side, which are then compared and evaluated.
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The Possibilities of Displacement Increase of 4C Zetor Engine
Zloch, Jan ; Franz, Rudolf (referee) ; Dundálek, Radim (advisor)
Diploma thesis aims on mechanical design of new concept of Zetor UŘ III engine with displacement increase and solves calculations of main and pin hydrodynamic bearings of crankshaft. Creo 2 CAD software is used for preparing mechanical design of this new concept. For computation and analysis of hydrodynamic bearings multibody model of crankshaft mechanism is used with flexible FEM model of crankshaft for solving dynamics of mechanism and performing hydrodynamic analysis of bearings in FEV Virtual Engine. Results of this diploma thesis demonstrate the feasibility of new concept of engine and serve as a basis for next engineering tasks before realization of concept.
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STABILITY ANALYSIS OF CUTTING PROCESS OF MACHINE TOOL WITH RESPECT TO CHATTER
Vetiška, Jan ; Marek, Jiří (referee) ; Singule, Vladislav (referee) ; Březina, Tomáš (advisor)
The thesis deals with building and utilization of mechatronic models which are based on modeling of system of rigid and flexible bodies. Such models are then used for analysis of behavior of complex systems, for instance machine tools. The work is concentrated on analysis of self-excitation of a machine tool. The appearance of the self-excitation during the machining may be influenced by several methods described in the work. The evaluation of the appearance of the self-excitation is analyzed via so called lobe diagram. It is necessary to know transfer function describing the impact of acting forces on the deformation of the system (machine tool in this case) for compilation of the lobe diagram. The whole structure of the model shows compliant behavior which dramatically influences the transfer function thus the approach to the modeling of mechanical parts as flexible bodies is proposed. There are created models of modally reduced flexible bodies based on modified CAD models which have same modal properties as non-reduced FEM models up to the maximal excitation frequency. The reduced models have significantly lower number of degrees of freedom and it is possible to work with them in multi-body simulation tools and at the same time they contain the information about the deformations. The work utilizes Graig-Bamton method which is implemented to the ANSYS. The whole model is consequently built and analyzed in ADAMS. It is possible to export the linearized model of the system in form of state matrices which are used for writing of the transfer function. The conditions of stability of the machining process are then evaluated via the lobe diagram. The proposed thesis presents the modeling of mechatronic systems with stiff and rigid bodies. The approach may be used for analysis of machining tools as well as for development of advanced mechatronic systems with active damping, etc.
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Analyses of Mechanical Tasks in ADAMS
Rybár, Šimon ; Švancara, Pavel (referee) ; Hadaš, Zdeněk (advisor)
The aim of this thesis was to create parametric models of technical systems in Adams software. The simulations were made to analyze the systems from kinematic and dynamic point of view. In some cases, the simulation results were compared with the results obtained by the analytic method. The thesis is divided into three chapters. The first defines the area and aims of the thesis. The second one defines multibody system and closely presents the software and its features. The third chapter contains five different examples which demonstrate the abilities of Adams. In the conclusion, own information, overall rating and educational recommendations are summarized.
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Multi-Body Computational Modeling of Transmission Dynamics
Líčeník, Adam ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
This diploma thesis is focused on compiling a computational model of the transmission of a Zetor Forterra HSX tractor in the Multibody software MSC ADAMS environment. It analyses the issue of creating gears in terms of vibration and noise. The thesis describes the creation of computational model which is used for simulation of the load conditions during tractor operation. The methodology is applied to a single-stage gearbox in which is verified. Then it is used on a model of a real tractor gearbox. The response of the input load conditions is projected during the forces in the engagement of the gears which are transmitted to the bearings.
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Plain Bearings for CI Tractor Engine
Petr, David ; Ramík, Pavel (referee) ; Dundálek, Radim (advisor)
This thesis deals with the hydrodynamic plain bearings tractor diesel engine. The first part is closer acquainted with the hydrodynamic bearing, its principles and materials used. The next part work deals with the multibody system adams-engine. The main part of this work is to model the crank mechanism and its storage in hydrodynamic bearings in the MBS program and the subsequent simulation under different operating conditions.
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Behaviour of Plain Bearings under Various Working Conditions
Lábus, Jiří ; Svída, David (referee) ; Dundálek, Radim (advisor)
This diploma thesis is devoted to problems of crankshaft plain bearings at five-cylinder in-line engine. Document body describes behaviour of plain bearings under various working conditions. To needs of the hydrodynamic bearings simulations is created the cranktrain virtual model. Next part of hereof document deals with problems of bearing shell design. Is created survey of the bearing materials and shortly described technological processing of shell bearing. To understand complicated problems hydrodynamic lubrication is derived Reynolds differential equation and foreshadowed succession calculation dynamically loaded bearings. In final parts of this thesis are presented most interesting results obtained from computational analysis.
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Computational Modelling of Piston Ring Dynamics
Dlugoš, Jozef ; Raffai, Peter (referee) ; Novotný, Pavel (advisor)
Piston rings are installed in the piston and cylinder wall, which does not have a perfect round shape due to machining tolerances or external loads e.g. head bolts tightening. If the ring cannot follow these deformations, a localized lack of contact will occur and consequently an increase in the engine blow-by and lubricant oil consumption. Current 2D computational methods can not implement such effects – more complex model is necessary. The presented master’s thesis is focused on the developement of a flexible 3D piston ring model able to capture local deformations. It is based on the Timoshenko beam theory in cooperation with MBS software Adams. Model is then compared with FEM using software ANSYS. The validated piston ring model is assembled into the piston/cylinder liner and very basic simulations are run. Finally, future improvements are suggested.
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