円筒の張出し加工に関する研究(第1報)

Abstract

This paper deals with the analysis by the logarithmic total strain theory for the deformation of thin-walled cylinder of finite length subjected to hydrostatic internal pressure and axial load. The ends of the cylinder are closed and the radial displacement there is not permitted. It is assumed that the material of the cylinder is rigid-plastic and obeys the power law of strain hardening. The stress-strain relations similar to those of Hencky and von Mises' yield condition are used. The meridional profile of the cylinder after deformation is not assumed in the calculations. The maximum internal pressure is obtained in the case of internal pressure only as well as in the case of internal pressure combined with the proportional axial load before the analytical limit, which is incidental to the total strain theory, appears. Stress and strain distribution, critical expanding radius (radius at the center of the cylinder when the maximum internal pressure is attained), relation between the internal pressure and the center radius, etc. are obtained in relation to the length of the cylinder, strain hardening exponent, axial load, existence of die, etc.. The cylinder shows the maximum value of the critical expanding radius when it has a certain definite length.