球形圧力容器の破裂に及ぼす肉厚不均一性の影響

抄録

In this study，a method is developed to predict the burst pressure of spherical pressure vessels with non-uniform thickness. The commercial 6061-T6 aluminum alloy which has wide applications as a structural material in the transport machines and construction industries is selected for this study．At this study we focus on the spherical pressure vessels which have periodic thickness changes and is subjected to internal pressure loads．The elastic-plastic and damage properties of the material are estimated inversely from the uniaxial tensile properties，and the stress，strain and damage state of the spherical pressure vessel with non-uniform thickness is analyzed by the finite element method．The Quantitative analysis of the effects of thickness heterogeneity on burst pressure is conducted in two aspects: its amplitude and wavelength．The greater the amplitude of the thickness change， the lower the burst pressure，but the effect of wavelength on the burst pressure is less severe．Through the analysis of the simulation results，it is shown that Hill's material instability theory is effective as a bursting prediction method for spherical pressure vessels with non-uniform thickness．The degree of change in radial strain is also positively related to the instability of the material．When the local radial strain change drastically，it is often considered that the instability of the material occurs．