Burst pressure estimations of a composite pressure vessel accounting for the composite shell imperfections

The paper presents the numerical evaluation of the effect of possible imperfections on the burst strength of composite pressure vessel made by filament winding over a thin metallic liner. The damages and defects distributed over the composite volume that lead to deterioration of the mechanical properties or increase their scattering are considered. The burst pressure is predicted with finite element analysis by using progressive damage approach. The obtained results show a strong influence of initial imperfection in the composite laminate on the vessel strength. The performed calculations show that the failure of the weakest layers does not lead to loss of the load-carrying capacity of the composite shell and the structure burst occurs as results of the subsequent damage evolution process. Such phenomenon happens regardless of the level of initial imperfection.