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Loss of strength during welding aluminous alloys AW 6060
Sklenář, Martin ; Vaněk, Mojmír (referee) ; Sigmund, Marian (advisor)
The aim of the bachelor thesis is to qualify the welding procedure according to the standard ČSN EN ISO 15614-2. At the beginning of the work is introduced a company with which was this thesis made. This is followed by an assessment of the issue of aluminum. Furthermore, the mechanical properties of aluminum are discussed. Follows by part about welding specially about aluminium welding. In the practical part the samples were welded and subsequently evaluated, then the design and qualification of the welding process was made. In conclusion, the possibilities and results that have been achieved are summarized.
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Využitelnost recyklátu dřevovláknitých desek ve výrobě kompozitních materiálů
Valko, Filip
The research dealt with the issue of the usability of fiberboard recyclate in the production of composite materials based on particleboard and wood fiber. The investigated properties were moisture content, density, density profile, thickness swelling, flexural strength, modulus of elasticity and tensile strength perpendicular to the fibers. The results were evaluated in Excel after the tests. A comparison of the results between the different boards was then carried out. The use of recycled wood fiber in composite materials has a positive effect on the physical properties, modulus of rupture and tensile strength perpendicular to the plane of the board.
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Stanovení pružnostních a pevnostních charakteristik dřeva v čerstvém stavu
Ressler, Ondřej
The topic of this bachelor's thesis was the determination of the mechanical properties of wood in its fresh state. The investigated mechanical properties of the wood were investigated on summer oak wood (Quercus robur L.). For the experiments, three oak trunks were secured from which samples were made. Determination of elasticity and strength characteristics was determined by a destructive method with the help of a universal ZWICK Z050 machine. Destructive methods included tests in compression, tension and bending. Physical properties (density and moisture), strength limits and elastic moduli were determined for these tests. The investigated mechanical properties of oak were determined for two moisture conditions. It has been verified by statistical tests that heartwood has greater strength than sapwood. As a result, a correlation between moisture content and ultimate strength and flexural modulus of in bending.
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Cyclic plasticity and low-cycle fatigue resistance of materials prepared by the ColdSpray method
Brůža, Jaromír ; Šulák, Ivo (referee) ; Zapletal, Josef (advisor)
In the theoretical part, the diploma thesis focuses on Cold spray technology and parameters affecting the efficiency and quality of deposition. Next, there is an introduction to the fatigue process of materials. The theory is concluded with a summary of the current knowledge regarding materials created by Cold spray technology in the field of fatigue. In the practical part, volumetric bodies were created from the material EN AW7075. Specimens for tensile and fatigue tests were cut from the bodies by electrosparking. From the material and powder, metallographic cuttings were created for the determination of porosity using Archimedes’ principle, hardness according to Vickers and evaluation of EDS and EBSD analysis. The basic mechanical properties were determined from the tensile tests and the Wöhler-Basquin parameters were determined from the fatigue tests along with the life curve. Subsequently, a fractographic analysis of fracture surfaces using SEM took place.
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Structural-mechanical characteristics of the selected type of low-carbon steel after cold drawing and heat treatment
Stopka, Maroš ; Molliková, Eva (referee) ; Pacal, Bohumil (advisor)
This bachelor's thesis focuses on changes in the mechanical properties of low-carbon wire that has been cold-drawn and subsequently heat-treated. Mechanical tests, from which the values of elongation, yield strength and tensile strength were measured, were performed on all samples within 24 hours after they were collected. Two different production rates were established on the hot dip galvanizing line to achieve different time intervals of the annealing process. The experiment was performed at all stages of wire diameter reduction, including the input material. This work also includes metallographic analyzes of samples that have been both polished and etched. The most representative samples were selected for analysis. The results show that deformation caused changes in mechanical properties and an increase in strain hardening, which was subsequently removed by heat treatment.
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Posouzení kvality lepení u kombinovaných kompozitních materiálů na bázi dřeva
Krejčí, Filip
The aim of the bachelor thesis is to evaluate the bonding quality of wood-based composite materials. Chipboard panels from various manufacturers with representation in the Czech Republic will be selected. In the theoretical part will be briefly described the important parts of the production process and the factors influencing the properties of chipboard. In the practical part will be determined the methodology of the experiment and the subsequent testing to determine the physical and mechanical properties of the selected material. The bachelor's thesis will show tables and charts, which will be evaluated and commented in the end for practical use.
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Stanovení mechanických vlastností dřeva v čerstvém stavu
Jakeš, Ondřej
This bachelor thesis deals with the determination of mechanical properties of wood in a fresh state. The object of the research was Acer platanoides. The mechanical properties were determined using the destructive method on the Zwick Z050. The primary objective was to determine the density, the modulus of elasticity, the modulus of rupture and also to determine the relationship between the individual variables. The secondary objective was to use the results obtained and to compare the density variability along the trunk and the density dependence on the cardinal point.
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Stanovení pružnostních a pevnostních charakteristik dřeva v čerstvém stavu
Bielesz, Robin
This thesis examines the elasticity and strength characteristics of freshly felled timber. Specifically, the wood of Norway maple (Acer platanoides L.). There was a whole trunk of one tree from urbanized environment, which were marked the world sides. After production of individual samples with dimension od 20 × 20 × 30 mm it has been necessary for each sample to describe his former position in the trunk (height, location in the trunk, location of the world side). The final experiment was performed on the testing machine Zwick 050, samples were tested by destructive method by pressure along the fibers. Then the results were processed using program testXpert from Zwick. The result is how to change the density, strength and elasticity characteristics in different locations in tree trunk.
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Pružnostní a pevnostní charakteristiky lepeného nosníku využívajícího recyklovaného dřeva
Syrovátko, Jakub
The subject of the thesis was the analysis of recycled wood for the use of glued beams on selected mechanical properties. Recycled wood was used for this research. Test specimens, ie lamellas with dimensions of 2000 × 80 × 20 mm, were made of both recycled wood and healthy wood, which was subsequently glued into a laminated beam, always after an odd number of layers; 2000 × 80 × 100 mm. Subsequently, values of tensile strength and modulus of elasticity in cross-fiber compression were determined experimentally. The measured data were statistically analyzed and the results discussed and compared with the literature.
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