Comprehensive study of distributions of residual stress and Young’s modulus in large-diameter sugi (Cryptomeria japonica) log

Abstract Aged conifer forests in Japan are expected to produce large-diameter logs, defined as logs with a top-end diameter of 30 cm or more. However, the knowledge and techniques for industrial processing Japanese wood species have not been sufficiently developed. This study was aimed at characterizing longitudinal component residual stress distribution sugi (Japanese cedar, Cryptomeria japonica ), major tree cultivated Japan, yield primary lumber from is affected by magnitude pattern stress. The radial distributions released strain stress, tensile Young’s modulus, were measured using 63 logs. showed typical patterns reported previous studies: contraction near bark elongation pith strain, bark, compressive pith. modulus pattern: low high bark. difference between maximum minimum strains each log varied widely among individuals, which result wide variation crooking when rip sawing. uniformity axial symmetry experimentally confirmed, lays groundwork improved understanding