20.500.12556/RUL-170198 The influence of thermal modification, moisture content, frequency, and vibration direction plane on the damping of spruce wood (Picea abies) as determined by the wavelet transform method This article analyses the main effect and interaction of thermal modification, wood moisture content, frequency, and vibration direction on the damping of spruce wood. Samples were thermally modified at three different temperatures (180 °C, 200 °C, and 230 °C) and then equilibrated at four different relative humidities (RHs) (20%, 44%, 76%, and 88%). The specimens were then freely supported and excited with a hammer to vibrate freely. Damping at the frequencies of the first three bending vibration modes for vibrations in the radial (LR plane) and tangential (LT plane) directions was determined using the wavelet transform method, which enables a decoupling of the vibration modes and thus a precise and accurate determination of the damping values. Damping increases with the wood moisture content for different modification levels, whereby the damping in the LR vibration direction plane differs from the damping in the LT vibration direction plane. For an unmodified sample and at frequency at the first vibration mode, damping in the radial plane is greater than in the tangential plane, but the relationships change with RHs, modification levels, and vibration direction planes. The dependence of damping on various factors has a strong influence on the calculation of various acoustic indicators, where damping of the wood is considered for the calculation, since damping for the same sample differs depending on the direction of vibration and the frequencies at different vibration modes. damping factor logarithmic decrement natural frequency wavelet transform faktor dušenja logaritemski dekrement lastna frekvenca valčna analiza true false true Angleški jezik Slovenski jezik Članek v reviji 2025-07-02 14:45:02 2025-07-02 14:45:07 2025-07-04 03:54:45 0000-00-00 00:00:00 2025 0 0 17 str. iss. 7, [article no.] 1055 Vol. 16 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-01-01 630*8 1999-4907 10.3390/f16071055 241140227 RAZ_Merhar_Miran_2025.pdf RAZ_Merhar_Miran_2025.pdf 1 1A01F9C394E7B4E373249031745A0ADA 96597062c6805f826411301b26b357f796ce2cf4fcab6eef724e1d230b7b347f b25e289f-5740-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=212147 https://www.mdpi.com/1999-4907/16/7/1055 1 7ca9b1ae-5740-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=212146 Biotehniška fakulteta 0 0 0