National Repository of Grey Literature 2 records found  Search took 0.01 seconds. 
Topological optimization and lattice structures for aerospace components
Petržela, Zdeněk ; Hutař, Pavel (referee) ; Paloušek, David (advisor)
Low product weight in combination with high mechanical properties play a crucial role in reducing operating costs in the aerospace industry. For this purpose, topology optimization and lattice structures are used. Additive manufacturing processes enable the production of optimized parts with geometric complexity. So far, no clear and comprehensive approach for designing a machine part with reduced weight in this way has been presented. The aim of this work was to map the topology optimization process with the use of lattice structures, corrected by experimentally determined production limits. Furthermore, the work deals with the implementation of the proposed methodology in optimization of a real machine part, its production from AlSi10Mg metal powder using selective laser melting technology, and verification of its manufacturing accuracy and vibration response. To determine the production limits, a series of lattice strut tests were performed. According to dimensional, weight and porosity analysis of lattice struts, a minimum applicable cross-section of the strut was chosen. Struts with this cross-section were subsequently applied into the beam samples with the BCC and BCCz lattice structure. Based on the mechanical response, the BCCz lattice structure was selected for application in the optimized part. For a more accurate mechanical behaviour prediction, based on actual lattice structure response, corrected elasticity modulus and yield strength value for BCCz lattice type were determined. These parameters were applied into FEM simulation in the lattice optimization phase. After solving the problem of lattice structure geometry export from FEM software, the optimization methodology could be completely defined, the part was manufactured, and the design potential was verified.
Base frame´s oil system under the steam turbine and generator
Petržela, Zdeněk ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
This bachelor thesis describes problematics of the lube system of steam turbines as an important part for its operation. The beginning of the thesis offers an overview of steam engine and steam turbine development both at home and abroad and its working cycle. The main part of the thesis discusses lube system functions and components. Next section contains a summary of required turbine oil properties and effects that affect the oil during working cycle. The conclusion of the thesis is focused on lube system operating problems, their causes, consequences and recommendations for their preventing.