A three-dimensional progressive failure analysis of filament-wound composite pressure vessels with void defects

Composite pressure vessels are promising solution for storing compressed gas with the high strength/stiffness to weight ratio, but the accurate modeling of mechanical behavior under high pressure remains a huge challenge considering manufacturing-induced void defects. The void generating method is developed to construct the finite element model with voids explicitly constructed. A three-dimensional(3D) progressive damage model complied with the user-defined material subroutine (UMAT) is performed to predict the void defect introduced damage behavior and burst pressure of composite pressure vessels. It indicates that the predicted burst strength agrees well with experimental value, and with the pressure increasing, the damage of composite layers initially appears in the matrix of middle cylinder section and region near the equator. The matrix damage is dominant at the outset, then achieves a balance with the fiber damage, and finally comes in second until the burst failure of the composite pressure vessels. The void defects will result in the damage initiation, evolution and final failure of composite layers, and the clustered voids will deteriorate the local damage status, but will not change the general damage trend. The present damage failure analysis scheme can provide theoretical guidance for reliability evaluation of composite pressure vessels with void defects.