A NEW METHOD TO DETERMINE YOUNG'S MODULUS IN THE TANGENTIAL DIRECTION FOR HOLLOW TUBES, IN PARTICULAR HOLLOW PLANT STEMS

摘要

A method is described to obtain Young's moduli in the tangential direction by compressing hollow cylinders along a radial axis. For thin-walled cylinders ovalization can be described by pure bending. For thick walled cylinders shear strains have to be taken into account. The method is applied to the giant reed Arundo donax, where the stem is composed of different tissues. Within one of these tissues a gradient of stiffness in radial direction is observed. The analysis demonstrates that the theoretical description developed for the ovalization process can be applied even to this relatively complex composite material.