薄層除去法によって測定した樹幹の残留応力分布について

概要

論文の詳細を見る
In the previous report, the authors gave the following clear physical interpretation for the process of creation of residual stress in wood log : The distribution of residual stress in a tree is set by the superposition of growth stress on the outer layer of the tree. However, the precise measurement of residual stress in a tree trunk must be needed for estimating the mechanism of occurrence of growth stress from residual stress in a tree. Now, the experimental values for growth stress reported in literature are not residual stresses in a tree trunk but one-dimensional recovery strains. Therefore, the past data cannot be used for such a purpose. In the present study, the residual stresses in tree trunks have been measured by " thin layer removal method " proposed by Doi & Kataoka. The experimental results are shown as in Fig. 1. The tendency of residual stress distribution in both longitudinal and radial directions is similar to that of the past data. But, only in the tangential direction, the compressive stress appeared near the center of tree trunk. The residual stress in the tree measured by this method can be used for estimation of the mechanism of occurrence of growth stress in a tree.
1975-09-15