TY - CONF

T1 - The Effect of Material Fatigue on Differently Modified Wood

AU - Kupfernagel, Carlo

AU - Curling, Simon

AU - Spear, Morwenna

AU - Ormondroyd, Graham

PY - 2022/4/25

Y1 - 2022/4/25

N2 - Wood modification has become a thoroughly studied field of work over the last few decades, but the ability to produce larger quantities of modified timber on an industrial scale is a relatively recent accomplishment. It is therefore reasonable to consider different loading scenarios, such as dynamic loading which may result in material fatigue. Secondly, a key feature of modified wood is its resistance towards wood-destroying fungi. The question arises – does material fatigue have an effect on biodegradability? This study employs an alternative sample preparation, using a DMA instrument, to induce material fatigue in small specimens. A sinusoidal load with a maximum stress level (SLmax) of 20% was maintained for 25,000 cycles. This sample preparation is used to investigate the relationship of fatigue and biodegradability in Scots pine specimens treated with three different modifications: thermal, acetylation and phenolic resin. It was found that the alternative sample preparation caused differences in the sorption behaviour, as represented by the equilibrium moisture content (EMC). The MOE and MOR of differently modified woods were not significantly affected by fatigue cycling. Contrary to the authors’ expectations, fatigued samples showed a lower mass loss (ML) in fungal decay experiments than intact control groups. The alternative sample preparation inherits certain disadvantages, e.g., in terms of useable specimen size, that complicates the investigation of the original research question. Nevertheless, the observed trends favour a further investigation.

AB - Wood modification has become a thoroughly studied field of work over the last few decades, but the ability to produce larger quantities of modified timber on an industrial scale is a relatively recent accomplishment. It is therefore reasonable to consider different loading scenarios, such as dynamic loading which may result in material fatigue. Secondly, a key feature of modified wood is its resistance towards wood-destroying fungi. The question arises – does material fatigue have an effect on biodegradability? This study employs an alternative sample preparation, using a DMA instrument, to induce material fatigue in small specimens. A sinusoidal load with a maximum stress level (SLmax) of 20% was maintained for 25,000 cycles. This sample preparation is used to investigate the relationship of fatigue and biodegradability in Scots pine specimens treated with three different modifications: thermal, acetylation and phenolic resin. It was found that the alternative sample preparation caused differences in the sorption behaviour, as represented by the equilibrium moisture content (EMC). The MOE and MOR of differently modified woods were not significantly affected by fatigue cycling. Contrary to the authors’ expectations, fatigued samples showed a lower mass loss (ML) in fungal decay experiments than intact control groups. The alternative sample preparation inherits certain disadvantages, e.g., in terms of useable specimen size, that complicates the investigation of the original research question. Nevertheless, the observed trends favour a further investigation.

M3 - Paper

SP - 292

EP - 300

T2 - European Conference on Wood Modification, Nancy, France

Y2 - 25 April 2022 through 26 April 2022

ER -