Development of a special self-adaptive auxetic structure for protecting tree trunks from external damage

Tomažinčič, Dejan (author), Klemenc, Jernej (author)

The objective of this research is to present the development of an innovative tree protection structure. With the increasing population of wild animals, the number of tree trunk damages is rising. Similarly, frequent damages occur during intensive forestry operations and timber harvesting, where bark abrasions and direct mechanical injuries are common. For this purpose, a wire wrapping structure was developed, which allows for easy direct installation around the tree trunk. Numerical simulations were used in the design and optimisation of the protective net. An important innovation is the introduction of an auxetic structure, which allows for spatial expansion that is synchronous with the natural process of tree growth. Such structure also stretches along two axes as the trunk thickens, which is the exact opposite of how conventional materials behave. Due to the use of a steel-wire base, the structure is sturdy and durable with a good protective effect. On the other hand, the cellular pattern results in spring properties, which contribute to a moderate and constant surface pressure on the tree bark. The protective structure was experimentally manufactured and tested on an affected conifer tree Abies alba. Over a period of three years, it contributed to the stable recovery process of the tree's damaged bark and prevented further damage attempts.

• Language: English
• Keywords: fir tree, damage from wild animals, mechanical bark damage, auxetic structure, numerical simulations
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: Str. 1-14
• Numbering: Vol. 20, art. 100860
• PID: 20.500.12556/RUL-169542
• UDC: 621:582.091
• ISSN on article: 2666-7193
• DOI: 10.1016/j.tfp.2025.100860
• COBISS.SI-ID: 237990915
• Publication date in RUL: 03.06.2025

Record is a part of a journal

• Title: Trees, forests and people
• Publisher: Elsevier
• ISSN: 2666-7193
• COBISS.SI-ID: 56233987

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian

Abstract

Namen študije je prikaz razvoja novega tipa zaščitne strukture dreves. S povečevanjem populacije divjih živali narašča število poškodb debel dreves. Prav tako pogosto poškodbe nastajajo pri intenzivnih gozdnih posegih in spravilu lesa, kjer prihaja do obdrsanj in drugih direktnih mehanskih poškodb lubja. V ta namen je bila izdelana žična ovijalna struktura, ki omogoča enostavno direktno namestitev okoli debla drevesa. Pri oblikovanju in iskanju optimalnih oblik zaščitne ovijalne strukture so bile uporabljene računalniške simulacije in računalniško podprto konstruiranje CAD. Pomembna novost je vpeljava avksetičnega vzorca strukture, ki omogoča prostorsko raztezanje, kar je sinhrono z naravnim procesom rasti drevesa. Struktura se ob debelitvi debla tudi dolžinsko razteguje, kar je ravno obratno, kot se obnašajo konvencionalni materiali. Zaradi uporabe jeklene žične osnove je struktura čvrsta in obstojna z izkazanim dobrim varovalnim efektom. Po drugi strani celični vzorci takšni strukturi dajejo vzmetne lastnosti, kar prispeva k zmernemu in konstantnemu površinskemu tlaku pritiska na lubje drevesa. Varovalna struktura je bila eksperimentalno izdelana in preizkušena na primeru prizadetega drevesa iglavca Abies alba. Skozi periodo treh let je prispevala k stabilnemu procesu okrevanja poškodovanega lubja drevesa in preprečila ponavljajoče poskuse poškodovanj.

• Keywords: jelka, drevo hoja, vplivi gozdnih živali, mehanska poškodba lubja, avksetična struktura, numerične similacije

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: Z2-50081-2023
• Name: Razvoj celičnega kompozita s sposobnostjo transformacije celic z izbranim aktivacijskim mehanizmom