Low-velocity impact damages of filament-wound composite overwrapped pressure vessel (COPV)

Abstract

Low-velocity impact tests were carried out on filament-wound composite overwrapped pressure vessel (COPV) specimens at different impact energies and impact points to determine the low-velocity impact damages of wound composite structures. The anti-impact performance of the filament-wound COPV was compared with that of composite laminated and filament-wound composite plates. Different impact damage modes and damage mechanisms inside the wound COPV were investigated through ultrasound scanning, X-ray, and scanning electron microscopy. Results showed that the impact force–time response curve of the wound COPV can be divided into an ascending area, a plateau area, and a descending area. The duration of the plateau area increased with the increase in impact energies. The impact resistance of the filament-wound COPV was the best, followed by that of the composite laminated plate, and the filament-wound composite plate was the worst. The major damage modes of the filament-wound COPV under low-velocity impact included matrix breakage, delamination, and fiber breakage. Delamination in the COPV tube section mainly occurred between the spiral wound and hoop layers. Delamination at the head of the COPV occurred between different winding layers. Fiber breakage inside the COPV mainly developed in the fiber overlapping zone inside the spiral layer. Results indicated that the fiber overlapping zone was the weak part in the filament-wound composite structure.