RELATIONSHIPS BETWEEN DYNAMIC VISCOELASTICITY OF MOSOCHIKU (PHYLLOSTACHYS PUBESCENS) AND INTENODE NUMBER, AGE, AND SPECIFIC-GRAVITY

The relationships between dynamic viscoelasticity of mosochiku (Phyllo stachys pubescens) and internode number (the height above the ground), bamboo age, and specific gravity were studied by means of the free fl exural vibration method.The results obtained for bamboo were compared with those of sugi (Cryptomeria japonica D. Dan), hinoki (Chamaecypari s obtusa Endl,), and shide. (Carpinus spp.). The dynamic elastic modul us of masochiku was larger on the epidermis side than on the endodermi s side, and increased with increasing specific gravity on bath sides. However, the modulus was independent of internode number and bamboo ag e. Logarithmic decrement of mosochiku Tn-as larger an the endodermis s ide than on the epidermis side, and that for a young age was less than that for an older age. However, the decrement was independent of inte rmode number and specific gravity. The dynamic modulus and logarithmic decrement of wood were almost the same as those of bamboo of the same specific gravity, Therefore, it is thought that the mechanism of dyna mic viscoelasticity of both bamboo and wood is the same regardless oi differences in tissues and structures and is dependent: on their solid volumes.