Investigation on the calculation model of burst pressure for tube and casing under practical service environment

The burst strength of tube and casing is important to the storage and development of hydrogen gas and natural gas. Studies on the current classic models to calculate burst pressure of tube and casing show that they are not suitable to predict the burst pressure of tube and casing under modern manufacturing technology level due to without considering the effects of radius-thickness ratio and practical service environment (capped-end condition and capped-open conditions). Hence, for the thin-wall (20＜D/t＜40) tube and casing, based on the deformation instability and finite strain theory, this paper has established the equations to calculate burst pressure of thin-wall pipe under capped-end condition and capped-open conditions by adopting the power-law constitutive relation. For the thick-wall (5 ≤ D/t ≤ 20) tube and casing, based on the failure criterion of through-wall yield, the unified algorithms of burst pressure for thick-wall pipe under capped-end condition and capped-open condition have been derived by adopting unified strength theory. The burst pressure model which can calculate the burst pressure of thick-wall pipe under modern manufacturing technology level, has been presented combining with weighting twin shear stress yield criterion. Numerical and experimental comparisons show that the calculated results of this equation are closest to the test data, and its accuracy and reliability are obviously superior to other models, and the service environment of tube and casing has a great impact on the burst pressure.