Effect of span length on the impact bending strength of poplar and pine woods

Bal, Bekir Cihad

doi:10.15376/biores.16.2.4021-4026

“…Most size effect studies have been performed quasistatically. The results of one very recent study of the impact fracture of two different woods ( Figure 46 ) shows that the size effect may be more complicated in impact than at low rates of strain ( Figure 47 ) [ 166 ].…”

Section: Evidence Of Size Effects In Woodmentioning

confidence: 99%

“… Plots of the impact bending strengths of Poplar and Pine specimens as a function of the span length of the original specimens. From [ 166 ]. …”

Section: Figurementioning

confidence: 99%

Is Wood a Material? Taking the Size Effect Seriously

Walley

¹

,

Rogers

²

2022

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This review critically examines the various ways in which the mechanical properties of wood have been understood. Despite the immense global importance of wood in construction, most understanding of its elastic and inelastic properties is based on models developed for other materials. Such models neglect wood’s cellular and fibrous nature. This review thus questions how well models that were originally developed for homogeneous and effectively continuous materials can describe wood’s mechanical properties. For example, the elastic moduli of wood have been found by many authors to depend on the size of the test specimen. Such observations are incompatible with classical elasticity theory. There is also much uncertainty about how well elastic moduli can be defined for wood. An analysis of different models for size effects of various inelastic properties of wood shows that these models only approximate the observed behaviour, and do not predict or explain the scatter in the results. A more complete understanding of wood’s mechanical properties must take account of it being in some sense intermediate between a material and a structure.

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“…Most size effect studies have been performed quasistatically. The results of one very recent study of the impact fracture of two different woods (Figure 46) shows that the size effect may be more complicated in impact than at low rates of strain (Figure 47) [166]. The weakest link theories discussed so far have assumed that flaws are uniformly distributed, but due to the way trees grow, flaws are arranged anisotropically in timber/lumber [86].…”

Section: Preprintsmentioning

confidence: 99%

Is Wood a Material?

Walley¹,

Rogers²

2022

Preprint

1

0

View full text Add to dashboard Cite

This review critically examines the various ways in which the mechanical properties of wood have been understood. Despite the immense global importance of wood in construction, most understanding of its elastic and inelastic properties is based on models developed for other materials. Such models neglect wood’s cellular and fibrous nature. This review thus questions how well models that were originally developed for homogeneous and effectively continuous materials can describe wood’s mechanical properties. For example, the elastic moduli of wood have been found by many authors to depend on the size of the test specimen. Such observations are incompatible with classical elasticity theory. There is also much uncertainty about how well elastic moduli can be defined for wood. An analysis of different models for size effects of various inelastic properties of wood shows that these models only approximate the observed behaviour, and do not predict or explain the scatter in the results. A more complete understanding of wood’s mechanical properties must take account of it being in some sense intermediate between a material and a structure.

show abstract