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

Merhar, Miran (avtor), Moutou Pitti, Rostand (avtor)

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.

• Jezik: Angleški jezik
• Ključne besede: damping factor, logarithmic decrement, natural frequency, wavelet transform
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: BF - Biotehniška fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Datum objave: 01.01.2025
• Leto izida: 2025
• Št. strani: 17 str.
• Številčenje: Vol. 16, iss. 7, [article no.] 1055
• PID: 20.500.12556/RUL-170198
• UDK: 630*8
• ISSN pri članku: 1999-4907
• DOI: 10.3390/f16071055
• COBISS.SI-ID: 241140227
• Datum objave v RUL: 02.07.2025

Gradivo je del revije

• Naslov: Forests
• Skrajšan naslov: Forests
• Založnik: MDPI
• ISSN: 1999-4907
• COBISS.SI-ID: 3872166

Licence

• Licenca: CC BY-NC 4.0, Creative Commons Priznanje avtorstva-Nekomercialno 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc/4.0/deed.sl
• Opis: Licenca Creative Commons, ki prepoveduje komercialno uporabo, vendar uporabniki ne rabijo upravljati materialnih avtorskih pravic na izpeljanih delih z enako licenco.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: faktor dušenja, logaritemski dekrement, lastna frekvenca, valčna analiza

Projekti

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: P2-0182-2019
• Naslov: Razvojna vrednotenja