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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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Bridge crane two-girder
Vajmar, Jan ; Malach, František (referee) ; Malášek, Jiří (advisor)
This master’s thesis describes the design of two-girder overhead crane. At the beginning of the work are designed sectional characteristics of the girder and the crossbeam. Furthermore, they are calculated loads applied during crane operation. Following the determination of the static load and fatigue strength. All calculations are solved with respect to relevant standards relating to overhead cranes. The work also includes analysis of purchased components, which are geared motors, bumpers and drive (no drive) wheels.
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Processes of contact damage bearing materials
Chaloupka, Petr ; Dvořáček, Jiří (referee) ; Hort, Filip (advisor)
The focus of this bachelor’s thesis is treatise on processes of contact failures of bearings and theirs materials analyse type of degradation processes of material, contact fatigue strength and means of metering. In fine of bachelor’s thesis are given development of future tendencies in optimalization of bearings.
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Analysis of the use of Code_Aster in solving the limit state of fatigue strength
Busta, Michal ; Kovář, Jaroslav (referee) ; Vosynek, Petr (advisor)
This bachelor’s thesis deals with the analysis of the use of Code_Aster in the calculations of the limit state of fatigue strength. The first part is the research in fatigue analysis using the solver Code_Aster and in the second part the know-how of Code_Aster usage is used to solve three tasks of the limit state of fatigue strength. Acquired results are compared with analytical solutions and with the student licence of the numerical software Ansys Workbench 19.2. In conclusion, all the results are analysed.
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Bridge crane one-girder
Chroust, Martin ; Malach, František (referee) ; Malášek, Jiří (advisor)
The focus of this thesis is the construction of a single girder overhead crane. The goal is to render a crane construction according to preset parameters. The parameters include a lifting power of 8,000 kg, a 10,000 mm reach, a 2,400 mm wheelbase and a stroke of 8,000 mm. The thesis includes brief theoretical research focused on overhead cranes, their various types and description of their main components. Brief description of chosen parameters for the construction itself follows. The description of chosen parameters includes calculations of strain acting during operation, technical and stability parameters, essential for the construction. All calculations were made with regard to valid Czech technical standards and specialized literature which focuses on the construction of cranes and their parts. Finally, the thesis is extended by the required technical drawings.
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Design of Welded Joints
Kojecký, René ; Doman, Jozef (referee) ; Dlugoš, Jozef (advisor)
This bachelor thesis deals with international and standardized approaches of weld assessment. The aim was to create a clear set of rules and differences of individual methods. The processing was based on the available literature. The first part is devoted to a research study that deals with this issue. Subsequently, three methods were selected for processing and evaluation using FEM.
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The fatigue life of steel specimens under axial, torsional and combined axial-torsional loading
Mička, Jan ; Horníková, Jana (referee) ; Slámečka, Karel (advisor)
The master’s thesis deals with the fatigue life prediction under multiaxial cyclic loading. First, the fatigue process is discussed and the methods for fatigue life prediction under uniaxial and multiaxial loading are described. In the practical part, the accuracy of selected criteria is assessed based on experimental data obtained on cylindrical samples made of 1.2210 steel that were tested under synchronous symmetric axial-torsion loading. Application of criteria requires to determine the fatigue strength under pure axial and torsional loading.
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Mobile wall crane
Bábek, Tomáš ; Malach, František (referee) ; Malášek, Jiří (advisor)
This master’s thesis describes the design of wall mobile crane and its railway. At the beginning of the work research of suitable hoists is conducted according to important parameters. Following the calculation of basic loads applied during crane operation. Furthermore the determination of the static load and fatigue strength of selected part which is verified by MKP simulation. The work continues with design of selected parts of crane and its railway. This design is solved with respect to relevant standards. In conclusion the final design of machine is drawn.
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Fatigue analysis and life of steel structures
Dostál, Petr ; Šťastný, Antonín (referee) ; Kubín, Martin (advisor)
The thesis is focused on solutions fatigue´s analysis and consequently on persistence steel structures of engineering and building aspects. The theoretical part describes the influence of cyclic fatigue in steel structures, describe the basic characteristics of fatigue and its application, a description of the fatigue life curves and their subsequent mathematical approximation of both engineering and the building terms. The study also includes the calculation of fatigue real parts (structure) in mechanical engineering, depending on the operating conditions of the structure. The work is further prediction of the life of steel structures using damage accumulation hypothesis according to the nominal stress. The practical part composes an example of life calculation of drawbar tractor-trailer bogie suspension of engineering and building terms. An example serves as an algorithm solving the life prediction of engineering and building terms, and reveals the possibility of solving the life of engineering structures in terms of building. The comparison of both approaches is done in conclusion.
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