Abstract
Under the axial tensile force in the fiber direction the distribution of crystal lattice strain in the b-axis direction of the cellulose (I) in the cell wall of tracheids were measured by the X-ray diffraction technique using (040) reflection of cellulose micelles.
In this study the transit X-ray method was used and the diffraction profiles were obtained by 40sec fixed time and θ-2θ method. The macroscopic surface strains of the specimens in the fiber direction were measured by the electrical strain meter and resistance type strain gage, pasted on both sides of the specimens.
The lattice strain in the fiber direction was a little smaller than the surface strain of the specimens, but the average ratio of the lattice strain to the surface strain was in the range of 0.90∼0.97 below the surface strain level of 3000×10-6.
The lattice strains decreased with the increasing inclination from the fiber axis.
In the inclined direction from the fiber axis, the lattice strains were a little smaller than the normal strains of the specimen calculated from Eq. (10), of homogeneous orthogonal anisotropic body, but the appearance of distribution of lattice strains in the cell wall was similar to that of the normal strains of the specimens.
From those results it is considered that the micelles which were arranged in the cell wall have actually taken over a portion of the applied stress and acted an effective role in the mechanical properties of wood.
It is qualitatively observed that the micelles have largely been improved in their orientation by the axial extension in the fiber direction.
