|
|
Measurement of vehicle moments of inertia
Grác, David ; Hejtmánek, Petr (referee) ; Porteš, Petr (advisor)
This diploma thesis is concerned with selecting the appropriate method for determining the moment of inertia to the vertical, lateral and longitudinal axis through the centre of gravity of the vehicle. Using the special mechanical device, constructed on IAE was carried out repeated measurements of known mass properties in each axis. With the aid of obtained data was calculated measurement error. To compare the resulting values was created MBS model.
|
|
|
Crank mechanism with a high mechanical efficiency
Drápal, Lubomír ; Tůma, Jiří (referee) ; Páv,, Karel (referee) ; Píštěk, Václav (advisor)
This document describes the possibilities of increasing the mechanical efficiency of the crank train of an internal-combustion engine. For this purpose, a concept with a reduced number of main bearings is chosen and its contribution is verified experimentally. The proposed solution consists of an innovative crankshaft design of a four-cylinder spark-ignition engine with only three main journal bearings and laser-welded sheet metal crank webs. The new design is compared to the mass-produced one in terms of friction losses, vibrations and loading of engine parts by means of simulations of crank train dynamics using the Multi-Body System. The increase in vibration, accompanied by a reduction in friction losses, is compensated by a torsional vibration damper and its effect is experimentally verified. Experimental research of laser welds on the crankshaft in terms of fatigue life is also described. The overall potential is also summarised and further possible development of this innovative and patented design is outlined.
|
|
|
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.
|
|
|
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.
|
|
|
Computational Models of Transmission Dynamics
Czakó, Alexander ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
This bachelor thesis deals with a summary of knowledge about the computational models of transmission dynamics. Dynamics modelling has different levels of complexity. From the modal, harmonic analysis solved in the FEM, up to creating a virtual prototype in the MBS softwares. In the introduction, there are presented the basics of analytical dynamics and mechanical oscillation which are the basis of individual analysis. Vibration sources in transmission are described as well.
|
|
|
Dynamics Improvement of CNC Axis with Ball Screw
Ciklamini, Marek ; Blecha, Petr (referee) ; Březina, Tomáš (advisor)
This work deals with virtual designing of ball screw drives of CNC machine by modern software tools to approximate evaluation of dynamic behavior of real system. Realized multi body system of thrust axes actuated by synchronous motor is analyzed and after that are designed elements of control used for accuracy positioning of table.
|
|
|
Virtual prototype of mechatronic system
Dinga, Milan ; Březina, Lukáš (referee) ; Hadaš, Zdeněk (advisor)
This thesis deals with modeling of delta 3D printer virtual prototype and its co-simulation using software ADAMS and MATLAB/SIMULINK. The first part consists of virtual model creation and its kinematic analysis. Then a model of electric motors is created. The final part consists of co-simulation and control design.
|
|
|
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.
|
|
|
Virtual prototype of mechatronic system
Dinga, Milan ; Březina, Lukáš (referee) ; Hadaš, Zdeněk (advisor)
This thesis deals with modeling of delta 3D printer virtual prototype and its co-simulation using software ADAMS and MATLAB/SIMULINK. The first part consists of virtual model creation and its kinematic analysis. Then a model of electric motors is created. The final part consists of co-simulation and control design.
|
|
|
The influence of a computational model of crank train dynamics on engine block load
Charvát, Adam ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
This work investigates the influence of the computational model of the cranktrain dynamics on the engine block load around the main bearings depending on the discretization level of the bodies used. Four variants of the computational model of the cranktrain in the Multi-Body System software SIMDRIVE 3D are compared with respect to the load on the main bearings. Based on the obtained loads, a strength analysis of the EA211 series 1,5 MPI mass-production engine block, manufactured by ŠKODA AUTO, is performed, including the influence of pre-stress during the assembly of the cylinder head and bearing caps. To evaluate the results, a fatigue life calculation is performed, and the endurance safety factors in the grooves on the bottom of the engine block are compared.
|
guest ::
