Analysis of stress development during kiln drying of beech timber

cris.virtual.author-orcid0000-0002-6713-8077
cris.virtual.author-orcid0000-0003-0076-3190
cris.virtualsource.author-orcid5ad889ad-842c-4ab2-9a0e-ea77e6f75f9c
cris.virtualsource.author-orcidbe4662f0-4144-45b2-96f7-33f2859e6d5e
dc.abstract.enBefore use, timber must have reduced moisture content. Kiln drying causes cracking risk. This study aims to evaluate the risk of cracking during the drying of beech wood samples using the response surface methodology. Additionally, we aim to develop an empirical model that describes critical tensile stress during the early drying stages and the air parameters commonly used in kiln-drying schedules for beech timber, specifically, the effects of dry-bulb temperature (DBT) and wet-bulb depression (WBD). Nine options of drying conditions were analyzed in the study according to the Central Composite Design assumptions; they were combinations of three options of DBT (30, 40, and 50 °C) and three options of WBD (4, 5, and 6 °C). During the experiments, tangential shrinkage of the wood samples was completely restrained with a load cell that measured generated tensile drying stresses. The results of the ANOVA analysis confirmed that the DBT is the only factor significantly influencing the tensile stress at failure (σf). The second-order effect between DBT and WBD has also been confirmed. The drying condition causing the highest risk of cracking was shown using the multiple contour plots of tensile stresses and the moisture content at failure (MCf). Reliability theory was used to predict the cracking risk of wood tissue. The analysis confirmed the dependence of the cracking risk of wood tissue on drying conditions. When DBT is equal to 30 °C, the cracking risk increases as the air relative humidity (RH) decreases. However, during the drying of beech wood samples at a temperature of 50 °C, decreasing the RH in a range corresponding to the increase of WBD from 4 to 6 °C reduces the cracking risk, which is indicated by the lower moisture content at failure (MCf) of the wood samples.
dc.affiliationWydział Leśny i Technologii Drewna
dc.affiliation.instituteKatedra Nauki o Drewnie i Techniki Cieplnej
dc.affiliation.instituteKatedra Obrabiarek i Podstaw Konstrukcji Maszyn
dc.contributor.authorMajka, Jerzy
dc.contributor.authorSydor, Maciej
dc.date.access2025-06-17
dc.date.accessioned2025-09-18T10:02:43Z
dc.date.available2025-09-18T10:02:43Z
dc.date.copyright2023-05-27
dc.date.issued2023
dc.description.abstract<jats:title>Abstract</jats:title><jats:p>Before use, timber must have reduced moisture content. Kiln drying causes cracking risk. This study aims to evaluate the risk of cracking during the drying of beech wood samples using the response surface methodology. Additionally, we aim to develop an empirical model that describes critical tensile stress during the early drying stages and the air parameters commonly used in kiln-drying schedules for beech timber, specifically, the effects of dry-bulb temperature (DBT) and wet-bulb depression (WBD). Nine options of drying conditions were analyzed in the study according to the Central Composite Design assumptions; they were combinations of three options of DBT (30, 40, and 50 °C) and three options of WBD (4, 5, and 6 °C). During the experiments, tangential shrinkage of the wood samples was completely restrained with a load cell that measured generated tensile drying stresses. The results of the ANOVA analysis confirmed that the DBT is the only factor significantly influencing the tensile stress at failure (<jats:italic>σ</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>). The second-order effect between DBT and WBD has also been confirmed. The drying condition causing the highest risk of cracking was shown using the multiple contour plots of tensile stresses and the moisture content at failure (<jats:italic>MC</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>). Reliability theory was used to predict the cracking risk of wood tissue. The analysis confirmed the dependence of the cracking risk of wood tissue on drying conditions. When DBT is equal to 30 °C, the cracking risk increases as the air relative humidity (RH) decreases. However, during the drying of beech wood samples at a temperature of 50 °C, decreasing the RH in a range corresponding to the increase of WBD from 4 to 6 °C reduces the cracking risk, which is indicated by the lower moisture content at failure (<jats:italic>MC</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>) of the wood samples.</jats:p> <jats:p><jats:bold>Graphical Abstract</jats:bold></jats:p>
dc.description.accesstimeat_publication
dc.description.bibliographyil., bibliogr.
dc.description.financepublication_nocost
dc.description.financecost0,00
dc.description.if2,4
dc.description.number5
dc.description.points140
dc.description.versionfinal_published
dc.description.volume81
dc.identifier.doi10.1007/s00107-023-01967-y
dc.identifier.eissn1436-736X
dc.identifier.issn0018-3768
dc.identifier.urihttps://sciencerep.up.poznan.pl/handle/item/4909
dc.identifier.weblinkhttps://link.springer.com/article/10.1007/s00107-023-01967-y#Sec1
dc.languageen
dc.relation.ispartofEuropean Journal of Wood and Wood Products
dc.relation.pages1189-1200
dc.rightsCC-BY
dc.sciencecloudsend
dc.share.typeOTHER
dc.titleAnalysis of stress development during kiln drying of beech timber
dc.typeJournalArticle
dspace.entity.typePublication
oaire.citation.issue5
oaire.citation.volume81