Buckling reliability analysis of the metal liner of composite pressure vessel after autofrettage

A buckling reliability analysis method for the metal liner of composite pressure vessel was established. Based on the analytical model of influence of the depression on the pressure and residual moment of the liner interface, the local buckling analysis of the metal liner was carried out by combining the finite element numerical simulation analysis method. Based on Monte Carlo algorithm, sampling methods for design variables of composite pressure vessel liner and winding layer were established, respectively. The radial basic function (RBF) surrogate model was used to replace the finite element analysis model for the buckling calculation of the inner liner, and a fast analysis method for the reliability of the local buckling of the pressure vessel with metal liner after autofrettage was established. Taking a 30 L cylindrical fiber wound composite pressure vessel with metal liner as an example, the influence of the uncertainties of the design parameters of the inner liner and the winding layer on the buckling reliability of the inner liner was analyzed. The results show that the buckling probability of the liner is positively correlated with the autofrettage pressure within the calculated range. The influence of the liner thickness on the buckling probability of the liner increases approximately linearly with the increase of the autofrettage pressure. Considering the liner radius, the thickness of the winding layer and the modulus of the winding layer separately, the variation trend of the buckling probability with the autofrettage pressure is an increasing curve from slow to fast and then to gentle.