National Repository of Grey Literature 49 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
The developement of SLM laser strategy for lattice structure fabrication
Jaroš, Jan ; Dočekalová, Kateřina (referee) ; Vrána, Radek (advisor)
Additive technology (AT) is increasingly used to design unique parts, mainly due to the ability to produce complex structures such as lattice structures. However, this also includes the need to modify the process parameters or the production strategy of the AT, which is usually set to produce volume geometry. Using samples corresponding to the geometries of the lattice structures, the exact input values were measured, which were used to design the SLM (Selective laser melting) production process using a contour strategy. Thanks to this, vertical and angled (35.26°) struts with low porosity (up to 0.2 %), low surface roughness and high dimensional accuracy were produced. Porosity was measured on µCT, surface roughness and dimensional accuracy were measured on STL data. The results show that if the parameters of the SLM process are set correctly, it is possible to produce struts with low porosity and surface roughness using different combinations of laser power and scanning speed. The above findings were used in the creation of script that allow the selection of suitable process parameters to produce lattice structures.
Design of lattice structures for additive manufacturing using Selective Laser Melting technology
Vrána, Radek ; Maňas, Pavel (referee) ; Koutný, Daniel (advisor)
Metal additive technology allows to create objects with complex shape that are very difficult to produce by conventional technologies. An example of such component is a porous structure which is composed of periodical truss cells. This diploma thesis deals with the prediction of the mechanical properties of very small lattice structures made of additive manufacturing technology Selective Laser Melting. Using the proposed test specimens it was found that real dimensions of the trusses varies with size and orientation to the base platform. It was proposed and tested samples for rod tensile test made of SLM. Based on the real information about dimensions and mechanical properties of rods were predicted mechanical properties of lattice structures. A lot of mechanical tests were carried out to obtain the real mechanical properties. Test results and conclusions are described in the thesis.
Research on process parameters for producing of a structured material made by Selective Laser Melting technology
Richter, Vladislav ; Koutný, Daniel (referee) ; Vrána, Radek (advisor)
Selective laser melting (SLM) is one of additive technologies which allows manufacturing of components with very complex shape. One of the examples are porous lattice structures which are used in cosmonautics or medicine due to its good mechanical properties and low weight. In this work the influence of processing conditions (laser power and laser scanning speed) on material properties and geometry of as-fabricated trusses is investigated. Wide range of laser powers (100–400 W) and laser scanning speeds (1000–10000 mm/s) were used to determine optimum process parameters. Truss size, morphology and internal porosity was investigated using optical 3D scanner and X-ray micro computer tomography (mCT). Based on executed measurements optimum processing conditions were determined to be 350 W and 3000 mm/s. It is possible to manufacture faster geometrically more precise structures with equal internal porosity due to optimization.
Alternative design of the Dětkovice sewer network
Vrána, Radek ; Beránek, Josef (referee) ; Ručka, Jan (advisor)
The aim of this diploma thesis is to elaborate alternative designs of the Dětkovice sewer network. The first part deals with reasons of this work and the area of interest. In the next part the thesis deals with describe of current condition and proposed alternative designs. Furthermore, the economic assessment of alternative designs is elaborate.
Lattice Topology Optimization in ANSYS software
Černák, Martin ; Vaverka, Ondřej (referee) ; Vrána, Radek (advisor)
ANSYS is one of the first commercially available software which allows to make topology optimization of lattice structures. In this bachelor’s thesis optimization workflow, calibration of numerical model, validation of numerical results and revelation of influence of basic parameters involved in computation – cell type, minimum and maximum relative density, cell size and used discretization, are showed. Optimised part was compared by means of FEM and homogenization with available experimental data. Subsequently, influence of basic parameters was evaluated. It was shown that optimized structure is stiffer than benchmark and influence of basic parameters for mechanical response and computational complexity was introduced. Simultaneously, it was shown that homogenization overestimated mechanical response. The findings of bachelor’s thesis validate computational model in program ANSYS and can be used for more effective making of optimization models.
The study of the effect of additive manufacturing technology parameters Selective Laser Melting properties of the produced object
Žabka, Marek ; Koukal, Ondřej (referee) ; Vrána, Radek (advisor)
Metal additive technology currently finds use in a large number of industrial sectors. Mainly in domains such as aviation, medicine and astronautics, the emphasis is laid on mechanical and material properties of materials. This bachelor thesis deals with the research study of process parameters of technology Selective Laser Melting for material AlSi10Mg and stainless steel 316L. In thesis the impact analysis of main process parameters: laser power, scanning speed, hatch distance, layer thickness, especially on the porosity of the samples was carried out. Recommended settings for both materials were found based on the research of the current state. It was further found out the influence of parameters such as powder humidity or laser scan strategy.
Evaluation of Mechanical Properties of Lattice Structures Made by 3D Metal Printing
Pliska, Jan ; Skřivánková, Vendula (referee) ; Vrána, Radek (advisor)
Additive manufacturing technologies allow manufacturing of complex structures which are near impossible to manufacture by other more conventional technologies. A fine example of these complex structures is a periodic metallic micro-cellular structure This bachelor thesis is focused on summarization of known mechanical behaviour of lattice structures manufactured via Selective Laser Melting. This study also investigates suitable comparison criteria for lattice structures. Required values for determination of material constants were obtained from mechanical testing of real specimens. For faster evaluation of mechanical testing, automatic script in MS Excel was created. Research showed up some of the major parameters characterising the mechanical behaviours of lattice structures. It is possible to compare qualities of lattice structures based on criteria presented in this work.
Design of the Střížov sewer network
Vrána, Radek ; Úterský, Michal (referee) ; Ručka, Jan (advisor)
The aim of this bachelor's thesis is to elaborate the proposal technical design of the drainage village Střížov by combined sewer network. The first part deals about the area of interest. In the next part the thesis deals with the design and description of the location of sewer with respect to crossing with existing utility lines. It is also processed hydrotechnical situation of dewatered area and detailed longitudinal profile of the main collector.
Design of coating system with integrated milling head for 3D printing of metal prototypes
Rafaja, Hynek ; Vrána, Radek (referee) ; Koutný, Daniel (advisor)
The bachelor thesis deals with conceptual and design solution of coating system with integrated milling head for 3D printing of metal prototypes. It contains a simple overview of produced machines with similar technology. Further, the thesis contains conceptual solutions from which the final version is selected according to the specified parameters. Based onthe selected variant, a design of the application system with a built-in milling head for SLM280HL is created and detailed.
Review of materials used for the manufacturing by the Selective Laser Melting technology
Skalický, Petr ; Vrána, Radek (referee) ; Koukal, Ondřej (advisor)
This bachelor thesis aims to provide an overview of metallic materials (powders), which are used in the manufacture of parts and models with SLM (Selective Laser Melting) technology. It contains basic information about Rapid Prototyping (RP) technology and more detailed description of basic methods of RP, especially SLM. Next is a description of manufacture powders methods and its properties. The last section contains an overview of powdery materials as powders made of pure metal (one kind of metal material) and powders produced from metal alloys. This review focuses on the most important and most widely used materials for the manufacture of parts using SLM.

National Repository of Grey Literature : 49 records found   previous11 - 20nextend  jump to record:
See also: similar author names
3 Vrána, Roman
2 Vrána, Rostislav
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