%0 Research article
%T Displacement fields of wood in tension based on image processing: Part 1. Tension parallel- and perpendicular- to grain and comparisons with isotropic behaviour
%A Samarasinghe, S.
%A Kulasiri, G. D.
%D 2000
%J Silva Fennica
%V 34
%N 3
%R doi:10.14214/sf.629
%U https://silvafennica.fi/article/629
%X Displacement fields for tensile loaded rubber and wood in parallel- and  perpendicular-to-grain were obtained from digital image correlation. The  results showed that the digital image correlation can reveal fine  details of the nature of displacements in both rubber and wood. It was  found that when load is perpendicular-to-grain, the lignin matrix  produces uniform displacement fields similar to that of isotropic  rubber. Uniform displacement fields also observed when lignin is  involved in contraction due to Poisson effect in parallel-to-grain  tension. However, when tracheids carry the load in parallel-to-grain  loading, or are compressed in perpendicular-to-grain loading, a complex  displacement pattern distorted by internal shear stress and slippage is  produced.