Research

Variations in the morphology of wood structure can explain why hardwood species of similar density have very different resistances impact and compressive loading


Reference:

Hepworth, D. G., Vincent, J. F. V., Stringer, G. and Jeronimidis, G., 2002. Variations in the morphology of wood structure can explain why hardwood species of similar density have very different resistances impact and compressive loading. Philosophical Transactions of the Royal Society A - Mathematical Physical and Engineering Sciences, 360 (1791), pp. 255-272.

Related documents:

This repository does not currently have the full-text of this item.
You may be able to access a copy if URLs are provided below.

Abstract

A clear relationship has been established between the impact resistance and density of softwoods. However, there are hardwood species that have the same density but very different impact resistance. Softwoods are largely composed of tracheid cells (30-50 mum across); hardwoods have smaller fibre cells and also contain vessels (50-500 mum across). We examined white oak, beech, hickory and spruce. Compressive deformation was identified as the main mechanism for energy absorption in the type of impact test used. The disparate size of different wood cells in the hardwoods results in heterogeneous compressive deformation. During compression, large vessels cause smaller surrounding cells to be deformed more than in regions without vessels, increasing the energy absorbed. However, vessels that are too close together initiate kink banding at low loads and less energy is absorbed. The different morphologies of hardwoods are probably responsible for the variation in impact resistance between species of similar density. Drilling small holes along the grain of spruce, which naturally lacks vessels, mimicked the effect of vessels and did not reduce the energy-absorbing capabilities of the wood, despite the density being reduced. These findings could be used to increase the energy-absorbing capacity of synthetic foam materials.

Details

Item Type Articles
CreatorsHepworth, D. G., Vincent, J. F. V., Stringer, G. and Jeronimidis, G.
DOI10.1098/rsta.2001.0927
DepartmentsFaculty of Engineering & Design > Mechanical Engineering
RefereedYes
StatusPublished
ID Code2707
Additional InformationID number: ISI:000173869100008

Export

Actions (login required)

View Item