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Analysis of mechanical loads of selected structural parts of the excavator during operation
Busta, Michal ; Maňas, Pavel (referee) ; Vosynek, Petr (advisor)
This thesis is focused on the issue of computational modeling of soil harvesting while using the compact excavator from the company DOOSAN BOBCAT EMEA s.r.o.. The solution consists in creating two computational models in Rocky DEM and Ansys Mechanical. Rocky DEM software is used to solve the disconnection of soil by excavator components using the discrete element method. The outcome includes courses of forces and moments during the particular time of the individual joints of the model that was used. The obtained courses are then applied as an external load to the joint of a selected structural part of the analyzed model using a kinematic model in ANSYS Mechanical. The kinematic model consists of simplified geometry models of individual parts of the excavator arm, and a more detailed geometry model of the analyzed part of the arm. All the parts are connected to each other by rotational bonds representing joints. A static structural analysis of the mechanical stress is performed in ANSYS Mechanical for the prepared model during the simulated process. Finally, the selected structural part is assessed with respect to the elastic limit and fatigue strength.
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Device for filling tap hole of arc furnace
Juda, Lukáš ; Brhel, Jaroslav (referee) ; Malášek, Jiří (advisor)
Diploma thesis describes design and function verification of device for filling tap hole of electric arc furnace with tap hole diameter from 190 mm to 250 mm. The theses includes drive design calculation of chute swinging movement and bearing calculations. Another part of the thesis deals with verification of device functions which it is completed with process description of creating DEM simulation in program YADE. The thesis also includes basic experiments for determination angle of internal friction, angle of repose, coefficient of restitution and angle of material friction on a steel surface. Drawing documentation of selected assemblies is part of the thesis.
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Discrete modelling of railway ballast
Dubina, Radek ; Petr,, Frantík (referee) ; Eliáš, Jan (advisor)
For modeling of particulate materials, discrete element method (DEM) is commonly used. It perceives every particle like a single body. A railway ballast loading by trains is a typical example of a particulate discrete material. By a passing train, static and dynamic forces act on a track bed. Cycling loading results in pernament changes in the railway ballast. Cavity creation, agglomeration and ballast cracking lead to damages in rail traffic. Usage of the discrete element method may reveal the real issues of the railway ballast and it may leads to a reduction of costs associated with a design and repairs. This thesis is focused on the ballast modeling and identification of the discrete model parameters. Obtained results are compared with real experiments from Nottingham University.
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Design Optimization of Bucket Conveyors
Jonák, Martin ; Svěrák, Tomáš (referee) ; Zegzulka, Jiří (referee) ; Malášek, Jiří (advisor)
This thesis deals with a study of methods sufficient to describe the behavior of bulk materials (homogeneous and non-homogeneous) during their transport by bucket elevators in the application focused on the optimization of the bucket shape and also on the optimization of operating parameters of whole elevator. More specifically, this thesis is based on the studying and creating analytical and numerical computational models which are used for description of flows and deformations especially of particulate materials. Firstly, the thesis is focused on the process of discharging the bucket – the relationship among the shape of the surface of a particulate material and geometry, position and movement of the bucket. The beginning and way of discharge of the bucket will be determined. Secondly, the thesis includes the overall computational model of a bucket elevator which is based on discrete element method and presented in the case study. The goal is to determine the limits of some classical physical and mathematical descriptions.
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Mobile separator of the gravel and sand into individual fractions
Bezdíček, Petr ; Mergl, Václav (referee) ; Kašpárek, Jaroslav (advisor)
This thesis focuses on a research analysis of the technology of similar separators, the legislative regulations of the trailers and the conceptual design of the mobile gravel sorter itself. The thesis also includes functional, dimensional and force calculations of the individual nodes of the classifier. The classifier also includes conveyor belts for conveying material up to a height of approximately 1.5 m. Calculations and selection of the necessary drives for certain parts of the machine are also included. Furthermore, the work includes strength FEM calculations of selected structural nodes under different loading regimes. Finally, the DEM simulation of the sorting process in Altair EDEM is discussed. The thesis, including the assembly drawing, also includes a drawing of the weldment subassembly of the separation drum and frame. Selected shop fabrication drawings are prepared for this sub-assembly as a basis for fabrication of selected components.
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Analysis of mechanical loads of selected structural parts of the excavator during operation
Busta, Michal ; Maňas, Pavel (referee) ; Vosynek, Petr (advisor)
This thesis is focused on the issue of computational modeling of soil harvesting while using the compact excavator from the company DOOSAN BOBCAT EMEA s.r.o.. The solution consists in creating two computational models in Rocky DEM and Ansys Mechanical. Rocky DEM software is used to solve the disconnection of soil by excavator components using the discrete element method. The outcome includes courses of forces and moments during the particular time of the individual joints of the model that was used. The obtained courses are then applied as an external load to the joint of a selected structural part of the analyzed model using a kinematic model in ANSYS Mechanical. The kinematic model consists of simplified geometry models of individual parts of the excavator arm, and a more detailed geometry model of the analyzed part of the arm. All the parts are connected to each other by rotational bonds representing joints. A static structural analysis of the mechanical stress is performed in ANSYS Mechanical for the prepared model during the simulated process. Finally, the selected structural part is assessed with respect to the elastic limit and fatigue strength.
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Design Optimization of Bucket Conveyors
Jonák, Martin ; Svěrák, Tomáš (referee) ; Zegzulka, Jiří (referee) ; Malášek, Jiří (advisor)
This thesis deals with a study of methods sufficient to describe the behavior of bulk materials (homogeneous and non-homogeneous) during their transport by bucket elevators in the application focused on the optimization of the bucket shape and also on the optimization of operating parameters of whole elevator. More specifically, this thesis is based on the studying and creating analytical and numerical computational models which are used for description of flows and deformations especially of particulate materials. Firstly, the thesis is focused on the process of discharging the bucket – the relationship among the shape of the surface of a particulate material and geometry, position and movement of the bucket. The beginning and way of discharge of the bucket will be determined. Secondly, the thesis includes the overall computational model of a bucket elevator which is based on discrete element method and presented in the case study. The goal is to determine the limits of some classical physical and mathematical descriptions.
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|
|
Device for filling tap hole of arc furnace
Juda, Lukáš ; Brhel, Jaroslav (referee) ; Malášek, Jiří (advisor)
Diploma thesis describes design and function verification of device for filling tap hole of electric arc furnace with tap hole diameter from 190 mm to 250 mm. The theses includes drive design calculation of chute swinging movement and bearing calculations. Another part of the thesis deals with verification of device functions which it is completed with process description of creating DEM simulation in program YADE. The thesis also includes basic experiments for determination angle of internal friction, angle of repose, coefficient of restitution and angle of material friction on a steel surface. Drawing documentation of selected assemblies is part of the thesis.
|
|
|
Discrete modelling of railway ballast
Dubina, Radek ; Petr,, Frantík (referee) ; Eliáš, Jan (advisor)
For modeling of particulate materials, discrete element method (DEM) is commonly used. It perceives every particle like a single body. A railway ballast loading by trains is a typical example of a particulate discrete material. By a passing train, static and dynamic forces act on a track bed. Cycling loading results in pernament changes in the railway ballast. Cavity creation, agglomeration and ballast cracking lead to damages in rail traffic. Usage of the discrete element method may reveal the real issues of the railway ballast and it may leads to a reduction of costs associated with a design and repairs. This thesis is focused on the ballast modeling and identification of the discrete model parameters. Obtained results are compared with real experiments from Nottingham University.
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