アカマツ苗条の力学的性質に関する研究
Study on Some Mechanical Properties of Japanese Red Pine Seedlings

Yasuo OHSAKO, Hidetoshi MIYAGAWA
1977 Journal of the Society of Materials Science Japan  
In this study, we investigated some mechanical properties during growth of Japanese red pine (Pinus densiflora Sieb. et Zucc.) seedlings in air-dry. The results obtained are summarized as follows. (1) The values of tensile strength for pine seedlings having different growing duration varied depending upon the growing duration, and the variation could be divided into two steps on the basis of the degree of growth of pine seedlings; in the early step, pine seedlings contained only primary xylem,
more » ... nd, in the late step, pine seedlings contained secondary xylem. (2) The fracture surface by tension test differed depending upon the degree of growth for seedlings; at the early stage of growth, the fracture surface showed a simple fracture type at the cell wall in primary xylem, separation of intercellular layer, deformation in cell shape and etc., and, at the late stage of growth, the fracture surface showed a complex fracture type at each layer of cell wall in secondary xylem but did not show any clear deformation of cell shape and separation of intercellular layer. (3) Tensile relaxation tests were carried out on three pine seedlings having different growing duration. The difference in relaxation spectra among three seedlings could be shown by the position of maximum in the short-time range, and the position of the maximum seemed to be related to the growing of xylem tissue within seedlings.
doi:10.2472/jsms.26.424 fatcat:igl6ajcaavhsnoo4ganigr4wb4