木材乾燥応力の一測定法について

Abstract

A photoelastic method is employed for the determination of the stress built up in Buna wood (Fagus crenata Blume) block during vacuum drying at 40℃. The photoelastic polariscope used is shown in Fig. 1 and in Photo 1, and the photoelastic test piece which is a disc of Araldite Casting Resin is laid in the wood block (Fig. 4 and Photo 2). The relation between the photoelastic fringe order and the stress at the center of the disc is previously estimated (Fig. 8, 9 and Table 1). As the block dries, the change of the photoelastic fringe pattern is observed in the disc. From this pattern, the stress is calculated and is plotted against drying time in Fig. 10~13 and 15.