Vpliv površinske obdelave na akustične lastnosti lesenih resonančnih plošč

Skrt, Jakob (author), Straže, Aleš (mentor), Pavlič, Matjaž (co-mentor)

V raziskavi smo preverjali akustične lastnosti smrekovih (Picea abies (L.) Karst.) in javorjevih (Acer pseudoplatanus L.) lamel, dimenzij 400 mm × 75 mm × 3 mm. Akustične lastnosti lamel smo proučevali dinamično mehansko, s frekvenčnim odzivom pri prečnem nihanju. Lamele smo testirali neobdelane ter po površinski obdelavi s štirimi vrstami premazov: JOHA (J), domač (D), nitrocelulozni (NC) in poliuretanski premaz (PUR). Po površinski obdelavi se je povečala povprečna gostota lamel, bolj pri smrekovih, lastna frekvenca pa se je značilno zmanjšala. Površinski premazi, zlasti mehkejši (J, D, NC), še posebej pri smrekovini, so značilno povečali dušenje mehanskega nihanja (tanδ) lamel po površinski obdelavi. Akustične lastnosti lamel so se najmanj spremenile po površinski obdelavi s poliuretanskim lakom, ki pa značilno poveča gostoto in s tem težo resonančnih plošč. Nasprotno, pa je premaz JOHA najmanj vplival na povečanje teže resonančnih plošč, negativni učinki na relevantne akustične lastnosti (Δtanδ = +28,24 %. ΔACE = -30,44 %), pa so bili relativno majhni.

• Language: Slovenian
• Keywords: les, navadna smreka, gorski javor, akustične lastnosti, površinska obdelava
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [J. Skrt]
• Year: 2022
• PID: 20.500.12556/RUL-140890
• UDC: 630*829.1:630*812.1
• COBISS.SI-ID: 124233475
• Publication date in RUL: 21.09.2022

Secondary language

• Language: English
• Title: Influence of surface treatment on acoustic properties of wooden resonant panels

Abstract

In this study, the acoustic properties of spruce (Picea abies (L.) Karst.) and maple (Acer pseudoplatanus L.) lamellae with dimensions 400 mm × 75 mm × 3 mm were investigated. The acoustic properties of the lamellae were investigated dynamically-mechanically with the frequency response during free vibration bending. The lamellae were tested untreated and after surface treatment with four types of coatings: JOHA (J), domestic (D), nitrocellulose (NC), and polyurethane coating (PUR). After surface treatment, the average density of the lamellae increased, especially for spruce, and the natural frequency decreased significantly. The surface coatings, especially the softer ones (J, D, NC), especially for spruce, significantly increased the damping of mechanical vibrations (tanδ) of the lamellae after surface treatment. The acoustic properties of the lamellae changed the least after the surface treatment with polyurethane varnish, which significantly increases the density and thus the weight of the resonance plates. In contrast, the JOHA coating had the least effect on the weight increase of the resonance plates, and the negative effects on the relevant acoustic properties (Δtanδ = +28.24 %. ΔACE = -30.44 %) were relatively small.

• Keywords: wood, Norway spruce, Sycamore maple, acoustic properties, surface treatment