Martian Asseko Ella, Giacomo Goli, Claude Feldman Pambou Nziengui, Joseph Gril, Eric Fournely, Rostand Moutou Pitti
{"title":"Comparative investigation on viscoelastic and mechanosorptive creep behavior of two tropical hardwoods and one temperate softwood","authors":"Martian Asseko Ella, Giacomo Goli, Claude Feldman Pambou Nziengui, Joseph Gril, Eric Fournely, Rostand Moutou Pitti","doi":"10.1007/s00107-023-02002-w","DOIUrl":null,"url":null,"abstract":"<div><p>Two series of 3-point bending tests under constant mechanical load and temperature of 20 °C have been performed on two tropical hardwoods, <i>Aucoumea klaineana</i> Pierre (Okoume) and <i>Pterocarpus soyauxii</i> Taub (Padauk), and one temperate softwood, <i>Abies alba</i> (Silver fir). A first series of 14-day tests was performed at 10% stress level and 65% relative humidity (RH), with moderate step variations at 45 and 75% RH. A second series of 5-day tests was performed at 35% stress level and 75% <i>RH</i> with a stronger step variation at 45% RH. Deflection and transverse expansion were measured using linear variable displacement transducers. The results show that the first variation of RH always increases the deflection and that subsequent changes decrease (humidification) or increase (drying) it. It was also observed that Padauk has a higher viscoelastic response and a lower mechanosorptive response than Silver fir and Okoume. As an indication of interaction between viscoelastic and mechanosorptive behaviour, in 14-day test the latter influenced the former, with small increments of relative compliance at each cycle. The analysis of the mechanosorptive trajectories suggested the existence of a creep limit and confirmed that of pseudo-creep/recovery.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Wood and Wood Products","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s00107-023-02002-w","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FORESTRY","Score":null,"Total":0}
引用次数: 0
Abstract
Two series of 3-point bending tests under constant mechanical load and temperature of 20 °C have been performed on two tropical hardwoods, Aucoumea klaineana Pierre (Okoume) and Pterocarpus soyauxii Taub (Padauk), and one temperate softwood, Abies alba (Silver fir). A first series of 14-day tests was performed at 10% stress level and 65% relative humidity (RH), with moderate step variations at 45 and 75% RH. A second series of 5-day tests was performed at 35% stress level and 75% RH with a stronger step variation at 45% RH. Deflection and transverse expansion were measured using linear variable displacement transducers. The results show that the first variation of RH always increases the deflection and that subsequent changes decrease (humidification) or increase (drying) it. It was also observed that Padauk has a higher viscoelastic response and a lower mechanosorptive response than Silver fir and Okoume. As an indication of interaction between viscoelastic and mechanosorptive behaviour, in 14-day test the latter influenced the former, with small increments of relative compliance at each cycle. The analysis of the mechanosorptive trajectories suggested the existence of a creep limit and confirmed that of pseudo-creep/recovery.
期刊介绍:
European Journal of Wood and Wood Products reports on original research and new developments in the field of wood and wood products and their biological, chemical, physical as well as mechanical and technological properties, processes and uses. Subjects range from roundwood to wood based products, composite materials and structural applications, with related jointing techniques. Moreover, it deals with wood as a chemical raw material, source of energy as well as with inter-disciplinary aspects of environmental assessment and international markets.
European Journal of Wood and Wood Products aims at promoting international scientific communication and transfer of new technologies from research into practice.