|
|
Evaluation of load-deformation characteristics of glued timber using DIC analysis
Šot, Michal ; Vejpustek,, Zdeněk (referee) ; Vaněrek, Jan (advisor)
The work deals with issues of evaluation of the shear properties of timber structural materials, particularly CLT elements. The work contains an overview of extensive research so far presented scientific studies dealing with the characteristic shear properties of wood. In the practical part was carried out the experiment dealing with the failure mode of transverse lamellae of CLT elements that were exposed to shear stress. There were observed individual effects that this may affect the material properties. In the first part of the experiment were performed numerical models using FEM. In the second part, the test specimens were tested in three point bending. Here, attention was paid to the influence of macroscopic properties of wood on the distribution of stress cracks and shear strength, the tests were recorded using DIC system.
|
|
|
Analýza morfometrických parametrů tracheid dřeva smrku ztepilého (Picea abies (L.) Karst.) na výzkumné ploše Bílý Kříž a Rájec-Němčice
Novák, Tomáš
This thesis is about analysis of morphometric parameters of Norway spruce tracheid wood from research areas Bílý Kříž and Rájec–Němčice. Wood for examining was sampled from different heights of trees. Width of the annual ring and percentage of late wood was determined at macroscopic level. Annual ring width ranged from 2,2 to 4,5 mm. The percentage of late wood was found to be 24 %. Microscopic analysis of tracheid wood dimensions followed. Radial size of tracheids was determined and averaged 31 μm. Tracheid cell wall thickness ranged from 2 to 10 μm. The number of tracheids increases with trunk height as does the width of the annual ring. Wood density of sampled wood averaged 450 kg·m-3. The variability of the wood structure by radius and height was examined. Subsequently, the obtained data was compared with precipitation and temperature.
|
|
|
Evaluation of load-deformation characteristics of glued timber using DIC analysis
Šot, Michal ; Vejpustek,, Zdeněk (referee) ; Vaněrek, Jan (advisor)
The work deals with issues of evaluation of the shear properties of timber structural materials, particularly CLT elements. The work contains an overview of extensive research so far presented scientific studies dealing with the characteristic shear properties of wood. In the practical part was carried out the experiment dealing with the failure mode of transverse lamellae of CLT elements that were exposed to shear stress. There were observed individual effects that this may affect the material properties. In the first part of the experiment were performed numerical models using FEM. In the second part, the test specimens were tested in three point bending. Here, attention was paid to the influence of macroscopic properties of wood on the distribution of stress cracks and shear strength, the tests were recorded using DIC system.
|
|
|
Vliv variability stavby rezonančního dřeva na jeho akustické vlastnosti
Schwarzer, Martin
This work was the structure of resonant spruce wood devoted to. The tree-ring widths and summer wood measure were measured. By use of non - destructive methods their acoustic properties were measured - speed of sound, acoustic constant, logarithmic decrement of damping, acoustic wave resistance, wood - density and Young's modulus. Data were statistically analyzed and the wood structure coefficient of variation for each specimen was calculated. There were three different methodologies for verification of the wood structure variability effect formulated. Subsequently, it was found that it is possible to determine the effect on the acoustic properties of the wood macroscopic structure variability.
|
guest ::
